| ||||||
| 5/16 |
| 2012/8/28-11/7 [Computer/HW/Memory] UID:54466 Activity:nil |
8/26 Amazon medium instances (3.75GB RAM): 0.160/hour = $1382/year
Generic standard Linux VPS (4GB RAM): $480/year
Amazon costs more (but does offer superior scaling options).
\_ Amazon is $670 if you buy a year's usage up front (heavy util).
Why is heavy util less expensive than light util? |
| 2012/6/27-7/27 [Computer/HW/Memory, Computer/SW/OS/OsX] UID:54424 Activity:nil |
6/27 You can't put 16GB RAM in the new 13" Macbook Pro.
Fuck you Apple!
\_ Really? I know they say you can't put more than 8GB in the 13"
MBP, but I have 16GB in my 2011 13" MBP and it works perfectly.
\_ I thought the new ones have soldier on HD and RAM just like
the Macbook Air?
\_ AFAIK, only the new 15" MBP has the RAM soldered on its
motherboard. It looks like the 13" MBP's RAM can still
be upgraded, since OWC is selling a 16 GB RAM upgrade for
it:
http://eshop.macsales.com/item/Other%20World%20Computing/1600DDR3S16P
\_ That's true but the upcoming 13" retina coming out in
Sep/Oct (reliable source from an Asian supplier) will
be ALL soldier on component. FUCK YOU APPLE!!! |
| 2012/3/29-6/4 [Computer/HW/Memory, Computer/HW/CPU, Computer/HW/Drives] UID:54351 Activity:nil |
3/29 A friend wants a PC (no mac). She doesn't want Dell. Is there a
good place that can custom build for you (SSD, large RAM, cheap video
card--no game)?
\_ As a side note: back in my Cal days more than two decades ago when
having a 387SX made me the only person with floating-point hardware,
most machines were custom built.
most machines were custom built. -- yuen
\_ did that make you a better programmer/gamer/etc?
\_ No. I was writing a pre-emptive multi-threading library as
part of an effort to port some floating-point-heavy Unix code
to DOS for CS199. I couldn't figure out how to save the
"context" of Borland C++'s floating-point emulation library.
The options were to either mask context switching around all
floating point operation or get a co-processor. I ended up
getting the co-procoessor. -- yuen
to DOS for CS199 (http://ssli.ee.washington.edu/~bilmes
mypubs/bilmes1992-icmcmood.pdf). I couldn't figure out how
to save the "context" of Borland C++'s floating-point
emulation library. The options were to either mask context
switching around all floating point operations or get a
co-processor. I ended up getting the co-procoessor. -- yuen
\_ Why not Dell? What is it about Dell she doesn't like?
\_ Fry's? HP? Lenovo? The only place I have done this is Lenovo. |
| 2011/6/5-8/27 [Computer/HW/Memory] UID:54127 Activity:nil |
6/5 In an effort to stabilize our services, we'll be rebuilding parts of
the CSUA infrastructure over the course of this summer. To give us
some wiggle room, I've temporarily decreased soda's allocated RAM from
8GB to 2GB. If you need to run something that requires large amounts
of memory, please send mail to root@csua.org and we'll try to
accommodate your request. --jordan
-------------------------------------------------------------------------------- |
| 5/16 |
| 2011/3/26-4/20 [Computer/HW/Memory] UID:54062 Activity:nil |
3/19 When you're explaining the stack to people do you draw it with the
highest addresses at the top or at the bottom?
\_ When I explain any memory layout including stacks, I draw with the
highest addresses at the bottom. But I've seen people doing the
other way. -- yuen
\_ do you by any chance have seen or have a jpg of the full memory
layout of the program, eg: .text, .bss, .initdata, etc etc?
If not, can one get that info from the ELF spec? Thanks. |
| 2010/5/22-6/11 [Computer/HW/Memory, Computer/HW/Drives] UID:53841 Activity:nil |
5/22 Duke turns of its Usenet server:
http://news.duke.edu/2010/05/usenet.html
\_ Imminent death of the net predicted.
\_ :( Sucks. I wish Berkeley hadn't turned off Usenet, either. |
| 2010/1/26-2/8 [Computer/HW/Memory] UID:53665 Activity:nil |
1/26 What's a good motherboard I can get that will fit in a 1U
case, with sata connectors, gig-e ethernet, and lots of
slots for RAM? I also don't want to have to use expensive
double buffered RAM. Can you tell I havne't bought a PC in
years? thanks.
\_ Buy a mac. Haven't you heard? if you don't buy a Mac people
will put the electronic Black Spot on you and never talk to you
again. Or put you down for being poor. |
| 2009/12/7-2010/1/3 [Computer/HW/Memory, Computer/HW] UID:53574 Activity:nil |
12/7 How many TCP retransmits are too many? Here is what I get:
3594143433 segments received
3760174421 segments send out
3801829561 segments retransmited
\_ rephrase. you can never have too much money. or too little.
what is, is.
\_ You always get a few, but I have a bunch of squid servers that
I just noticed have 500/second, which seems really high to me.
They do about 20MB/sec at peak so this is a retransmit every
40K? This is kind of hard to believe, because they are working
fine.
More details have been requested so here they are:
Each server has apache and squid installed and serves about 10M
requests/day out of memory in 5ms or less. They are configured
as memory only squid servers. They are middle tier caching
servers, sitting between an application layer and an API.
They have 1Gb/sec uplinks to shared switches, which each have
1 Gb uplinks to the core routers. No other servers on the
switches are showing this behaviour and the switches themselves
are not overloaded. Further investigation shows that 99% of
the connections on the servers are sitting in TIME_WAIT, which
I actually think is the cause of these retrans. I am still trying
to figure out who is rudely dropping all their connections to
these servers, but it is hard, since all traffic is through a load
balancer (NetScaler). |
| 2009/4/20 [Computer/HW/Memory] UID:52878 Activity:nil |
4/20 Heil....HeilHitlerHe.. #In Memory of Adolf Hitler# ..Heil....HeilHitlerHe
Heil....ilHitlerHeil.... We will always remember ....Heil....ilHitlerHeil
Heil....Heil............. and cherish you. Your .....Heil....Heil........
Heil....Heil............. acts of selflessness ......Heil....Heil........
Heil....Heil........... will be passed down from ....Heil....Heil........
HeilHitlerHeilHitler... generation to generation. ...HeilHitlerHeilHitler
HeilHitlerHeilHitler... The lies that dishonor your .HeilHitlerHeilHitler
........Heil....Heil..... name will be vanquished. ..........Heil....Heil
........Heil....Heil.... You were a true patriot ............Heil....Heil
........Heil....Heil.... and a lover of all men, ............Heil....Heil
HeilHitlerHe....Heil... all races, all religions. ...HeilHitlerHe....Heil
ilHitlerHeil....Heil.. #In Memory of Adolf Hitler# ..ilHitlerHeil....Heil |
| 2009/4/9-13 [Computer/HW/Memory] UID:52829 Activity:kinda low |
4/9 Which is better designed/engineered for reliability, the SDCard
or the Compact Flash card? I'm IEEE and EE dumb but I do understand
a lot of RAM terms and design architectures.
\_ Mechanically, I think CF cards are more durable because there is
more plastic and the contacts are hidden. For example, I'd be
comfortable to let my toddler kid play with a CF card but not an
SD card. Electrically, I have no idea. |
| 2009/4/1-10 [Computer/HW/Memory] UID:52781 Activity:nil |
4/1 http://www.google.com/mobile/m/brainsearch/intro_android.html |
| 2009/3/30-4/3 [Computer/HW/Memory, Computer/HW/Drives] UID:52772 Activity:nil |
3/30 CF/SD Disk database:
http://robgalbraith.com/bins/multi_page.asp?cid=6007 |
| 2009/3/19-23 [Computer/HW/Memory, Computer/SW/WWW/Browsers] UID:52731 Activity:moderate |
3/19 Any comments on IE8? How's its memory usage?
\_ Who cares. Microsoft will eventually push it onto everyone.
Accept your fate.
\_ Well, if IE8 uses less memory than Firefox 3, I'll get it now
instead of wait for it to be pushed. |
| 2009/3/16-23 [Computer/Companies/Apple, Computer/HW/Memory] UID:52722 Activity:nil |
3/16 Does anyone know what type of flash is used in the iPhone and how many
5A writes the flash memory could handle before failing? I'm wondering why
MobileSafari doesn't support paging to flash "disk". As is, it reloads
pages all the time, which sucks. |
| 2009/2/20-25 [Computer/HW/Memory, Computer/SW/OS/VM] UID:52616 Activity:nil |
2/20 Why flash ram will get you into trouble, in the long run:
http://www.pcper.com/article.php?aid=669
This is worse than over-clocking your computer. There's data
involved.
\_ What's your point? That flash supports a fairly limited number of
write cycles? We knew that already.
\- I am not the OP but dont think you're inquiry is very
thoughtful. This may be another case of "physical difference"
[between rotating mag storage and memory cell storage] cant
be abstracted away by software emulation" [in this case
focusing on the write/erase asymmetry]. An older example of
this with another hyped technology was ATM emulation of
Ethernet and the problem of doing broadcasts. |
| 2009/2/13-18 [Computer/HW/Memory, Computer/Domains] UID:52565 Activity:nil |
2/13 Question about memory relocation:
These days most h/w has a relocation register. Could the relocation
address be stored on disk or in kernel memory vs. in a register? Yes,
that would be slow but is it possible? Do you *need* a relocation
register or does it exist purely for performance reasons? I was
reading some paper written by IBM in the 1960s that seemed to
imply the former and I don't understand why that would be.
\_ What "relocation register" is this? If you're talking about the
one that (say) the IBM 7090 used for time-sharing, that's been
obsolete for 30 years; modern machines use virtual memory. (And
the tables defining the virtual-memory mapping are in fact stored
in kernel memory, since they're too big to fit in a register.)
Or did you have something else in mind?
\_ Yes, but modern machines still have a base register. Do
they need it?
\_ What do you mean by a "base register"? It would help if you
could say exactly which register you're talking about on some
real architecture (x86, PowerPC, MIPS, etc.), or at least if
you could describe what this register does.
\_ Because comparing 1960s computer hardware to today's is like asking
why drivers need a whip to make their cars drive faster because
you saw a picture of a horse drawn carriage.
\_ Well, no. Modern hardware still does it that way. The
question is: Does it *have* to? |
| 2009/1/21-26 [Computer/SW/Languages/Java, Computer/HW/Memory] UID:52436 Activity:nil |
1/21 If I have a linked list of structs and many of those structs have
members that are structs then what is the best way to free() the
memory when I am done with them? I thought I would walk the list
and do a free() on each member of each struct, but that generates
errors like free(): invalid pointer, presumably because I don't
always allocate memory in each struct. No, I never took a class in
memory management (obviously). In a Java World I don't worry
about all this! ;)
\_ Why don't you just check the pointer before calling free? i.e.
if (p) { free(p); }
\_ This was my first inclination and it doesn't change anything.
\_ This should have no effect in this case. The if only checks if
p is null, and if p is null, most versions of free will ignore
p is NULL, and if p is NULL, most versions of free will ignore
it anyway.
\_ All versions. It's a requirement in the standard.
\_ Hah, you assume all libc implementations are
compliant. Well, okay, things are better these days.
That said, if you aren't allocating the memory for the pointer,
you NEED to set the pointer to NULL. Preferably at the point
that the enclosing struct is allocated. Otherwise that pointer
may just be nonsense, which the if won't catch.
\_ Well, do the structs contain other structs, or pointers to other
structs? If struct A contains struct B, struct B is allocated
and free'd as part of struct A.
If struct A contains a pointer to struct B, you need to make sure
you're allowed to free the pointer before you do, perhaps there
are multiple pointers to B, and B shouldn't be free'd until all
the pointers are done.
If you are supposed to free pointer to B, but you think you might
be accidentally freeing it twice, you're going to have to be more
careful and figure out where exactly you should free it. There's
no easy way out of that.
\_ You need to define the difference between and owning an object and
referring to one. It's a logical difference -- the owners are
responsible for lifetime, referring pointers just are assigned.
\_ You're not doing something like the following, right???
while (p != NULL) {
free(p);
p = p->next;
} |
| 2008/12/18-2009/1/2 [Recreation/Dating, Computer/HW/Memory, Computer/SW] UID:52277 Activity:nil |
12/18 I'm loving the Privacy Browsing feature on Safari. I turn it
on, browse porn, then turn it off, and no one using my
computer would ever know that I browsed porn (no history,
no cache, nada). Loving it man.
\_ The guy with the backdoor knows. Also, the shadow knows.
\_ That may be the case and I don't really care about the
guy with the backdoor. The most important thing is that
my kids and my wife don't know about it.
\_ But it's advertised as being useful for gift shopping!
You horrible, horrible man.
\_ And tax cuts are good for THE PEOPLE! |
| 2008/12/4-10 [Computer/HW/Memory, Computer/HW/Drives] UID:52172 Activity:nil |
12/5 What would you guys think of this?
TYAN Tank barebone
http://tyan.com/product_barebones_detail.aspx?pid=353
2x Intel Quad Xeon E5420
http://www.newegg.com/Product/Product.aspx?Item=N82E16819117147
16GB ram
http://www.newegg.com/Product/Product.aspx?Item=N82E16820134633
SAS hard drives
http://www.newegg.com/Product/Product.aspx?Item=N82E16822116058
Total cost <$3000, and it seems like this would be an ESX supported
configuration if we ended up going that way (and there's no reason
that it would preclude any other virtualization option either)
The goal here would be to eliminate the other servers in various states
of 'broken' (scotch, screwdriver, lifesaver) and replace it with this
one. Once it was up and tested, we'd migrate soda there and then reuse
the hardware from Soda for something else. Thoughts?
\_ Why do you believe soda would not run on a $1-1.5k machine:
3gz proc + 1tb disk + ~4gb memory. I suppose something on the
higher end of this range with two slower processors might be
better than a 1proc. I'm guessing you'ld be better off with
one two lower end machine. Especially if you want one to play
around on.
\_ He's talking about replacing 4 servers with 1 server, not
just replacing soda. Soda is already way overpowered for
what it's doing right now. It doesn't need to be a dedicated
machine anymore.
After that I really can't tell what you're trying to say. |
| 2008/9/20-23 [Computer/HW/Memory, Computer/HW/CPU] UID:51241 Activity:low |
9/20 I am running NAT on an Extreme Networks switch connected to a
Cisco switch at GigE speeds. Copying a file across the same link
w/o using NAT gets about 25 MB/sec, but with NAT turned on I get
2.5 MB/sec. The CPU is 98% idle and there is plenty of RAM. I know
that NAT in s/w has an overhead but could it realistically be a
factor of 10 slower?
\_ what kind of file copy?
\_ NFS or SFTP. Same symptoms with either.
\_ Are you sure it is not your test platform that is slower? This
seems really crappy. Are you perhaps having a duplex mismatch
problem on the switch the NAT is connected to?
\_ What test platform? You mean the one I am copying with? I
said that I get 25 MB/sec with NAT off and 2.5 MB/sec with
NAT on - using the exact same hardware. Therefore, I doubt
it is a duplex problem or it would be present both times. |
| 2008/9/4-8 [Politics/Domestic/Election, Computer/HW/Memory, Computer/SW/WWW/Browsers] UID:51059 Activity:nil |
9/4 Someone asked yesterday about the Obama/Ayers link. It took me a while
to find a link I was happy with, this one is ok. This guy goes into
excruciating detail about the Annenberg Challenge and CAC over a
number of blog posts. The full Annenberg documents were only recently
released, and this post predates the release. The documents are still
being digested, so this is far from the final word.
Anyway, it is pretty obvious that Obama and Ayers had a close working
relationship for at least 6 years (the real relationship almost
cetainly predates this), in which they funneled millions to Ayers'
causes and students. It's also quite obvious that Obama has been
highly disingenous about this relationship, and many of his statements
about it have been blatant falsehoods. ("Our kids went to school
together", etc)
http://csua.org/u/m9b
\_ Yes, Obama supports terrorism and wants to KILL WHITEY.
\_ It looks like Obama has really been trying to improve the schools,
which is great. I think I am going to give him another $2300.
\_ Might want to look into what he was spending that money on
first. The challenge itself was deemed an utter flop. $100mil
down the hole.
\_ Deemed an utter flop by who? This guy is not a reliable
source.
http://preview.tinyurl.com/554pov
The Annenberg Challange is hardly the radical far-left
proposal this guy makes it out to be.
\_ Sorry, it was a flop _in Chicago_. That is, it had no
effect on student performance in Chicago. Your link is an
overall evaluation, so not really interesting for this
discussion.
Also, it was deemed a flop by the Consortium of Chicago
School Research (CCSR) in 2003.
\_ Yes, that is interesting. I will have to do some more
research. But I think it is amusing that an effort to
try and weaken the hold of the teacher's union is called
a communist tactic by this guy.
\_ I with you agree there. -op
\_ I agree with you there. -op
here are some new numbers (VM Size in MB reported by Task Manager):
2.0.0.16 3.0.1
- Startup, empty the cache. 13 23
- Go to http://www.yahoo.com 17 40
- Open 6 news pages in 43 69
6 new tabs.
- Close the 6 tabs above. 35 54
- Open the same 6 news pages 44 71
in 6 new tabs again.
- Close the 6 tags again. 38 53
So, after opening and closing the same tabs a second time, Firefox 3
still uses more memory than Firefox 2. Any idea? Thanks.
\_ The delta between 2 "close the 6 tabs" lines is 3 megs for FF2
and -1 megs for FF3. The general problem with FF2 was it tended
to leak memory over time. For a desktop app, an extra 10 megs
is minimal, but since people like to have long lived browser
sessions, FF2's habit of slowing growing up to 2 gigs of memory
is a real problem.
\_ Dunno, I notice better memory usage with lots of tabs open.
Firefox 2 used to go into the 500 MB range after a while,
Firefox 3 typically doesn't go above 400 MB.
\_ I used to have to restart my browser every day. I don't have to
with FF3.
\_ FF3 does seem more crashy though.
\_ Anyway, you made your point. He has extensive political connections
to an ex-WU guy. A big yawner to me, but perhaps middle America
cares. I kind of doubt it. |
| 2008/8/8-13 [Computer/HW/Memory] UID:50822 Activity:nil |
8/8 Just got my 16GB Rally2 USB flash drive, for $50. I can't believe the
pace of technology.
\_ http://woot.com has an 8GB Kingston DataTraveler 100 for $20+s/h. |
| 2008/6/9-12 [Computer/HW/Memory] UID:50203 Activity:nil |
6/9 Video RAM question:
Let's say I need to display a shape model that was ~3 million
plates that are each 72 bytes (216MB). Do I have to have a video
card that has more than 216 MB of RAM or can the system dip into
main RAM in order to display it? As I understand it, the VRAM is
a buffer but what happens when the buffer fills? In this instance
my video card has 64 MB of RAM and the image displays fine. Is
the rest of the image resident in system RAM? Do people get video
cards with more VRAM for performance reasons (VRAM is faster and
dual-ported) or because they can display images they never could
otherwise? Compare a system with 16GB RAM and 64 MB VRAM to one
with 1 GB RAM and 2 GB VRAM.
\_ That wildly depends on how the data is presented to your card.
\_ Please elaborate.
\_ If you present the data to your card the right way, it can
store the vectors directly. If you don't, it can't.
\_ So what if it can't if I have 16 GB of main RAM? Can I
use that or not? Why would I not want to? That is,
what does storing directly buy me? Can I display my
model in either case but with a performance penalty?
Excuse my ignorance, but I am not a gamer or anime
freak and never had a graphics class. I realize you
touched a little bit below, but I've been reading
about rendering pipelines all day and there's not been
much that talks about the role of the h/w in this or
what happens when you run out of video RAM.
\_ If you do "immediate" mode then you're limited by the
bus speed to the video card. If you can cram it all
onto the card, you're theoretically maximizing the
hardware performance. -emarkp
\_ Are there any other penalties? Just the penalty
of the speed of the VRAM vs. RAM and the
offloading of the main CPU in favor of the GPU?
I don't see the bus speed as a limiting factor.
You have to load it all into VRAM over some bus
anyway, right? I realize say AGP might be
faster than PCI but I am more concerned by how
the size of VRAM impacts the problem than by
issues of throughput, which are clear-cut. If I
have 256 MB of VRAM and a 1 GB image then what
happens? Does the video card swap to main RAM?
\_ At this point, you leave generalities and it
depends on the card, and the quality of the
driver. If the card runs low on memory, it can
dump whatever it needs to render, and then pull it
back from main memory when necessary. -emarkp
Typically cards do 16 bits of floating point, but that's
moving up to 32. The rendering pipeline today is basically
transforming triangles modelspace->worldspace, lighting,
worldspace->cameraspace. This can be done in "immediate"
mode, where each triangle is provided from the program running
in the CPU to the video system (D3D, OpenGL, etc.=> video
card) or in buffered mode (historically "display lists" on
OpenGL though that included much more than just geometry)
commonly called "vertex buffer objects". If there's room on
the card, you can push a bunch of geometry into the card, then
just tweak the input values and do everything very
efficiently. If there isn't room on the card, then the video
memory is mostly 1) frame buffer (what you see) and 2) texture
memory.
http://en.wikipedia.org/wiki/Rendering_pipeline
John Carmack (Id software, etc.) believes he's solved the
megatexture problem (imagine a whole world or large
environment that can be textured down to tiny detail),
with little or no performance issues (implemented in their
upcoming game, Rage). He says his next project is to do the
same with geometry. So things may be changing in the next few
years. -emarkp |
| 2008/4/3-9 [Computer/HW/Memory, Computer/SW/OS/Windows] UID:49655 Activity:nil |
4/2 Anyone try vmware player and notice that network performance
becomes terrible? I mean things like webpages timing out, etc.
This is in NAT mode on a windows XP host running a windows 2K guest.
\_ I use VM Server on XP Pro running XP Pro guests in NAT mode. No
such problem.
\_ I use VM Server on XP Pro running two XP Pro guests in NAT mode. No
such problem. However, if I run three or more guests, everything
becomes slow (not just network), and Task Manager on the host shows
that the CPU rarely goes to idle even though I'm not doing anything
It's not a problem with RAM since Task Manager shows that Commit
Charge Total is still less than the physical RAM.
on the host or the guests. It's not a problem with RAM since Task
Manager on the host shows that Commit Charge Total is still less
than the physical RAM.
\_ It's a little bit worse, but not much worse. Do you have enough
RAM? Everything is slow without it - and it should be allocated.
\_ I actually meant the network performance inside the guest.
It seems fine on the host. The host has 2 GB, and the guest
is allocated 512 MB, so I don't think that should be a problem.
I'm not doing anything particularly resource-intensive.
\_ 512 MB might not be enough. Increase that. In my
experience (Win XP guest on MacOS host) I started with
512 MB allocated and was unhappy until I doubled that.
\_ Hmm, Win2K should require substantially less memory than
XP, but it's worth a try I guess. My suspicion is
actually that a large number of TCP connections is
handled badly somewhere (maybe in vmware's nat service),
since webpages nowadays tend to retrieve random images
from a whole bunch of different places, etc.
\_ Maybe, except that my network performance (also
using NAT) is not anywhere near as bad as yours. |
| 2008/3/31-4/6 [Politics/Foreign/Asia/China, Computer/HW/Memory] UID:49619 Activity:nil |
3/31 Dear Chinese people who are into feng-shui and szhuan4-ming4.
There are a few main ways to szhuan4-ming4. If memory serves
right, one of them is called zji3-wai1 and the other one is
called zji3-ping2. Is that right? Where can I get more informatino
on this? Thanks for any pointer.
\_ http://en.wikipedia.org/wiki/Fortune-telling#Asian_fortune_telling
It lists four major methods and some other methods.
\_ http://chinese-astrology.blogspot.com/2005/08/zi-wei-dou-shu-what-is-it.html
The first one is called Zi3 Wei1 but I don't know other methods. |
| 2008/2/21-25 [Computer/HW/Memory, Computer/SW/Security] UID:49208 Activity:nil |
2/21 Cold Boot Attacks Against Disk Encryption:
http://www.schneier.com/blog/archives/2008/02/cold_boot_attac.html
http://citp.princeton.edu/memory |
| 2008/2/20-22 [Computer/HW/Memory] UID:49204 Activity:nil |
2/20 In python, say I have a function:
def hello(a,b,c): ...
and I have a list l that contains 3 entries (l[0], l[1], l[2]),
how can I pass it easily in the following manner?
hello(l)
\_ hello(*l)
\_ Oh cool, thanks!!! |
| 2007/12/14-19 [Computer/HW/Memory] UID:48806 Activity:nil |
12/14 What the heck are SDHC flash memory cards?
what's the SD?
can i use SDHC cards with my old stuff?
\_ SD - secure digital, HC - High Capacity. You probably cannot
use SDHC in old stuff b/c HC is a different memory addressing
scheme. Some old stuff like Treo 650s can be hacked to work
w/ SDHC cards, but most can't. |
| 2007/3/15-20 [Computer/Rants, Computer/HW/Memory] UID:45990 Activity:nil |
3/15 YEEEHAAAA!!!!
'ATLANTA - A panel of Georgia lawmakers signed off Thursday on a plan
to create a Confederate heritage month, even as legislative leaders
reacted coolly to a push to apologize for the state's role in slavery.
Sen. Jeff Mullis' bill would dub April as Confederate History and
Heritage Month to honor the memory of the Confederacy and "all those
millions of its citizens of various races and ethnic groups and
religions who contributed in sundry and myriad ways to the cause of
Southern Independence."'
http://news.yahoo.com/s/ap/20070315/ap_on_re_us/confederate_month
\_ WTF? Is that a joke?
\_ Nope. YEEEEHAAAAA!!! |
| 2007/3/4-6 [Computer/SW/Languages/C_Cplusplus, Computer/SW/Mail, Computer/HW/Memory] UID:45865 Activity:nil 54%like:45917 |
3/4 trn crashes on me upon startup:
"*** glibc detected *** malloc(): memory corruption: 0x08091618 ***
Abort"
Any idea? Thanks. |
| 2006/10/25 [Computer/HW/Memory] UID:44960 Activity:nil |
10/25 Anyone know if ACP-EP memory is a problem? Looks like it's the
least expensive where I am, but I don't have any idea of its quality. |
| 2006/8/30-9/3 [Computer/HW/Memory, Computer/HW/CPU] UID:44208 Activity:nil |
8/30 I just configured a Dell XPS M1710 with the 2.0-GHz 4MB-cache
Core 2 Duo with WinXP Pro and 3 years warranty. $3,106 after tax!
Dang, some rich kids will be spending bux on their computer for
undergrad WoW.
\_ Excuse my lameness, but it this faster than a 3GHz Pentium D ?
I know MHz doesn't matter anymore, but it doesn't feel right.
\_ I believe all Pentium D's up to 3.6 Ghz are blown out of the
water by a 2.0-GHz C2D with 4MB-cache.
http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2795&p=12
The above has desktop Core 2 Duo vs. Pentium D, not mobile C2D,
but you also need to consider the 1.86 C2D desktop has only
2MB of cache.
\_ In my (limited) experience, Core (1) Duo 1.86GHz >> Dual Xeon 3.0 |
| 2006/8/25-29 [Computer/HW/Memory, Recreation/Humor] UID:44155 Activity:nil Cat_by:auto |
8/25 USB teddy bear holds data, scares children:
http://tinyurl.com/m9ak4 -John |
| 2006/8/4-6 [Computer/HW/Memory] UID:43907 Activity:nil |
8/4 What happens if you boot a computer with no RAM installed? Will it
POST? Can you get into the BIOS config? Or does it just beep at you?
\_ I think you get a blank screen and the infamous 3 beeps.
\_ Depends alot on your PC BIOS, but most just simply refuse to POST.
\_ Absolutely. No way. Sometimes. -proud American |
| 2006/8/1-6 [Computer/HW/Memory] UID:43855 Activity:nil |
8/1 I'm looking for a 1GB and a 2GB USB flash drive.
All the reviews I've seen on amazon seem to be very mixed.
I'd like something rugged, simple, fast, and reliable.
Any suggestions? Thanks
\_ I like the Kingston DataTraveler Elite 2GB. I backup my pr0n to the
the encrypted partition, it's fast, and it's reliable. Other flash
drives have the cool slideout (so you don't lose the cap), but it's
hard to find one with real hardware-based encryption. FYI, the
"Privacy Edition" is the same thing except you don't have a public
partition (basically so ppl don't have to think), and I don't care
for the "Migo Edition" and similar solutions where you load your
user prefs from your flash drive (too heavyweight IMO).
http://www.newegg.com/Product/Product.asp?Item=N82E16820189017
If you don't want hw encryption, you can go much cheaper, just go
to http://newegg.com, pick 1GB or 2GB, and sort by Rating.
\_ Get a U3 Smart flash drive. This week Office depot 1GB $25.
http://www.newegg.com/Product/Product.asp?Item=N82E16820189017
\_ One of my recent new toys has been a Corsair FlashVoyager, which
I've been very happy with. It supports partitioning and all that
good stuff and is fairly snappy for a USB thumbdrive. Plus it's
built like a brick and hard to lose (rubbery surface stays in my
pocket much, much better). IMO, teeny-tiny ones (Cruzer Micro or
smaller) are just too loseable
http://www.newegg.com/Product/Product.asp?Item=N82E16820233009
I think it's also slightly cheaper than a few months ago.
--michener
\\\_ Thanks y'all! -op
\_ I've got a Memorex 2GB Traveldrive. Never had any problems
it. I carry all kinds of porn wherever I go. -proud American |
| 2006/7/14-18 [Computer/HW/Memory, Computer/SW/Unix] UID:43671 Activity:nil |
7/14 So as I understand it, Intel introduced Hyperthreading because the
penalty for a cache miss or branch misprediction on Netburst was huge
so to make up for it they could work on a different thread while
waiting for memory latency. Given that the Core2 architecture has
such a wide execution path, couldn't they use HT to try and keep all
those execution units full?
\_ I attended one of Intel's talks on campus and the "huge penalty"
myth is a myth. As the number of pipelines increases, the depth
of the miss and a pipe flush is longer, yes. However, keep in mind
that since each stage in the pipe is shorter the clock cycle is
also faster. Thus, in terms of absolute time (time=number of
pipes that need to be flushed * cycle time), the increase in P4
from the old architecture is only increased by ~20% time, which
is insignificant in computer science speak.
As for keeping execution units full, it's very much application
dependent. Even with the huge instruction reorder mechanisms some
applications still can't utilize them all. |
| 2006/6/21-26 [Computer/HW/Memory] UID:43455 Activity:nil |
6/21 When they say Conroe chips will run on a 1066MHz FSB, what kind of
RAM does that imply? DDR2-522 or DDR2-1066? |
| 2006/4/4 [Computer/HW/Memory, Consumer/Audio] UID:42650 Activity:low |
4/4 To whoever recommended crucial, thanks for the tip, but
I just cancelled my order with them. Their credit card
clearing operation is pathetic, and customer service was
rude and unhelpful. They were unwilling and/or unable to
try to figure out how to process an out-of-US order. Fuck
them. Thanks anyway. Any other suggestions? -John
\_ Wow, sorry to hear about that. I've also used http://memoryx.net
\_ Don't apologize, I appreciate the tips. I'll try them. -John
\_ I've bought ram from 1-800-4-Memory (http://www.18004memory.com
They were cheap and decent, but I have no idea how the service
is outside the US. Another option could be to try amazon.co.uk.
\_ Crucial is just a memory maker. They're resold by a zillion other
companuies around the world. http://pricegrabber.com, http://pricewatch.com,
http://shopping.com, froogle, http://pricescan.com, etc to find a reseller.
\_ John, here is a hint: American Express.
No, I am not kidding. Most of online store in USA requires
billing address in USA. If you are using some non-USA card,
you are going to get into trouble. American Express appearently
only check the zip code. So, as long as the zip code is correct,
it will go through. In my part of town, my zip code is 3 digit,
and i managed to get it through by padding it with zeros at the
front of digits :p kngharv
\_ I don't think it is true--I work with Versign and AVS is
available for AmEx as well. It's up to the vendor whether
to use it or not.
\_ The thing is, I already have 2 gold cards (one Swiss and
one Chilean.) AmEx is fine, but I have never ever ever
had trouble with either of my Visas except with US vendors.
I'd prefer not to have another card floating around just to
deal with people who're too lazy to implement proper ID
checking (which this is a case of.) And as for zip codes,
many of the shops I've had trouble with don't understand that
a lot of the world doesn't work that way (my zip code right
now is "Las Condes", go figure.) Thanks though. -John
\_ Amazon seems to sell some Crucial memory. I've bought from
Amazon abroad and shipped to the US, and that went smoothly.
Perhaps the reverse is also smooth. |
| 2006/4/3-4 [Computer/HW/Memory] UID:42624 Activity:nil |
4/4 Anyone have a recommendation for where I can get a cheap 1GB
memory dimm for a 12" Powerbook? -John
\_ http://www.crucial.com (I don't know if it is cheap)
\_ Seconded. And the price is worth not having to ship back
faulty or non-compatible units.
\_ Thanks much, I just ordered there. Price-wise it's
perfect--even with import tax & shipping it's much
cheaper than Apple. -John
\_ Thirded, always had good experience with http://crucial.com, the prices
are not rockbottom but they are good, and I've never had a
problem, plus they have fast shipping.
\_ I just cancelled my order with them. Their credit card
clearing operation is pathetic, and customer service was
rude and unhelpful. They were unwilling and/or unable to
try to figure out how to process an out-of-US order. Fuck
them. Thanks anyway. Any other suggestions? -John |
| 2006/4/1-2 [Computer/HW/Memory] UID:42598 Activity:nil |
4/1 April is the cruelest month.
\_ breeding lilacs out of the dead land,
mixing memory and desire, stirring dull
roots with spring rain. |
| 2006/3/16-18 [Computer/HW/Memory] UID:42277 Activity:nil |
3/16 Mr. Phelps, this thumbdrive will self-destruct in 5 seconds:
http://tinyurl.com/pqkd4 (everythingusb.com) |
| 2006/2/17-20 [Computer/HW/Memory] UID:41910 Activity:nil |
2/17 What's the basic technological difference between EEPROM and
flash? Both program and erase using electricity...
\_ http://en.wikipedia.org/wiki/Flash_memory
\_ i thought eeprom erases with uv light
\_ ee = eletrically eraseable.
you are thinking of eprom or just plain shitty prom. |
| 2006/2/7-9 [Computer/HW/Memory, Computer/HW/Drives] UID:41761 Activity:kinda low |
2/7 I have a little multi-threaded server I'm writing, and I log at
the start of each call and at the end of each call. I log by
having a global lock file, lock, write, flush, unlock. This
seems like a bottleneck, is there a better way to log from a
multi-threaded server? Perhaps something like syslogd where I
could send messages to another process that would log for me?
(This would avoid the flush because it could keep running even if
the server crashes) Order in the log is not terribly important,
since a quick run through sort on the date will order that for me.
\_ What about a separate thread to manage the log? Put the msgs
in a shared queue, and have the logging thread write out the
messages later on.
\_ Not a bad idea, but if the server crashes I won't get the
messages just before the crash.
\_ There isn't really a way to avoid this problem in a
threaded app, except to move logging into a separate
process, such as syslog. If you are going to use
syslog(3), then you probably should openlog(3) prior
to starting your threads.
\_ How about each thread keeps its own log file, as well as writing
into a shared buffer which is flushed periodically to the common
log. That way in normal operation you have just one log to look
at, but when the server does down, you can examine the per-thread
logs. In normal operation, other threads will not have to wait
while one thread flushes its own log.
\_ I don't think there is a problem with just using write(2), it is
atomic and writes to buffer cache so a crash of the process won't
be a problem. With some applications, mmap(2) is better, but
depends on what you are doing. --jwm
\_ Note that write(2) is only atomic if nbytes is less than
PIPE_BUF (which is at least 512 according to POSIX). That
said, if you know your log messages will be reasonably short,
this is the way I'd go. -gm
\_ I was assuming he wanted to write a file, and in that case
I suspect that the atomicity extends at least to the page
size, though I may be wrong. --jwm
PIPE_BUF (which is at least 512 according to POSIX). You
can also get short writes, even if nbytes is less than 512,
if you're writing to a pipe or other space-limited fd. -gm
\_ Really? I didn't know that. Related, why is it called
write(2) rather than just write()?
\_ That represents that it's in section 2 of the man pages which
is the system call section. "man write" shows you the page
for the write utility to send messages to someone's tty.
"man 2 write" gets you the write system call.
\_ On Slowlaris: man -s 2 write
\_ Unix needs it's own diversity day.
\_ Stop geeking and find a hot gf during undergrad before it's
too late!
\_ I'll add to my previous comment some speculation. If you're
using stdio or iostreams, I suspect your flush is not syncing to
disk, but merely calling write(2) to flush it's internal buffer.
To test this you could use ktrace to see the calls it is making.
Of course you will still may need a lock to protect the library
you are using as I suspect these are not threads safe. And if
you don't like locks, you could use sprintf() and write(2) with
no locks. --jwm
\_ Tried using sprintf and write(2) with no locks, and it
doesn't quite work. The log file is a bit messed up. It
appears that concurrent calls to write can screw things
up. (Not threadsafe) But, it seems like in that case
the lock shouldn't be costing as much as I had supposed
anyway, since the write is just being buffered somewhere.
\_ Having every thread in your application serially accessing
a piece of code that does I/O is a really bad thing, you
really don't want to do this. Grabbing a lock and
sticking data on some list that another thread comes and
consumes will be a lot faster (just makes sure that other
thread doesn't hold the lock while writing the data, then
you've lost everything you gained in the first place.) As
for needing to get everything logged in case your
application crashes, you are never going to get that
anyway. If you have 10 threads waiting to grab the lock
and the server crashes those 10 logging statements will be
lost no matter what.
How often you log should influence your choices here, are
we talking tons of debugging logging or just 1 or two
lines a second? If a lot of logging keep in mind that
things like gettimeofday are syscalls and those are more
expensive. Is it really that important that you get the
date of the log statement exactly right? Can you get the
time before or after you get the lock? If you really need
to order your logs, maybe just use a long that you
increment per statement?
Getting a lock is done entirely in user space (and
normally in just a few asm instructions AS LONG AS THERE
IS NO QUEUE FOR THE LOCK. Locks get a lot more expensive
to use (by orders of magnitude) when any blocking has to
occur. If you are worried that a lot of threads are going
to be blocking at a time keep the critical section as
small as possible, it really helps.
Finally, while logging can be more complex than it looks
at first, it is also a pretty solved problem. There are
tons of free logging libraries out there that do all this,
do it well, and do it fast. It might be worth your while
to just use existing code.
\_ Interesting. Thanks. What could I search for to find some
of these logging libraries? I didn't have much luck last
time I tried. (The critical section was already tiny, just
the write and the flush. The string is all built outside
the critical section.) -op
\_ You do understand that I/O is THE most expensive thing
you can do don't you? Just because it is only 2 lines
of C code doesn't mean the critical section is fast. |
| 2006/1/25-27 [Computer/HW/Memory] UID:41522 Activity:nil |
1/25 I'm working on a program in windows which is having memory problems.
When I allocate memory with new or malloc, it seems to reserve more
memory than I request (using VM Valiator to monitor this). Even if I
delete the memory there is still a "reserved" chunk that doesn't seem
to ever get used by other code. I'm using VC++ 6 btw. Anyone have an
idea of what might be going on?
\_ When you malloc memory it gets a page at a time. Also freeing
memory will rarely actually give that memory back. You do
understand memory pages right?
\_ Yes. The memory involved here is in multiples of megabytes
however. |
| 2005/12/11-14 [Computer/HW/Laptop, Computer/HW/Memory, Computer/HW/IO] UID:40960 Activity:nil |
12/11 NEC: products of the future
http://www.nec-design.co.jp/showcase |
| 2005/11/16-18 [Computer/HW/Memory, Computer/Networking, Computer/SW/Unix] UID:40627 Activity:nil |
11/16 Your friend's kid's gadget is cooler than yours
http://www.nytimes.com/2005/11/17/technology/circuits/17pogue.html
\_ That's awesome!
\_ Wait how does it know what you clicked on? Don't you need
to store the picture somewhere (in memory) and an input
method (like a tablet)?
\_ I got to play with one of these a couple of months ago before it
came out. It is pretty cool, although the one problem it has it the
only feedback it can give is audio. Thus, it wouldn't be very easy
to use in a classroom w/o disturbing everybody. Also, in order to
use it, you need to write on special paper that costs about $1 a
sheet. Its covered by very tiny dots so the pen knows where it is
located on the paper at all times. But I will say that their future
plans for the Fly pen seem really cool (wireless sync and such).
\_ It comes with headphones and paper is about 8 cents/sheet.
\_ I think reading its manual alone will make me dizzy. |
| 2005/11/7-8 [Computer/HW/Memory] UID:40475 Activity:nil |
11/07 Does 168pin DDR (PC3200) memory needs to be used in pairs? Thx!
\_ Ideally, in pairs. Dual-channel mode will be activated if the
memory is of the same size and in the right slots.
If not added in pairs or of memory of different size or in the
wrong slots, then the memory will operate in single-channel mode.
Your mobo manual should tell you the same thing.
Your mobo manual will also tell you which slots to use for a pair
(e.g., for my Asus, it was every other slot that was a pair).
Same deal with DDR2.
\_ Dual-channel mode is much faster?
\_ From what I've read, for your typical program you will see
1-5% difference.
\_ Dual channel nearly doubles your memory bandwidth.
If "typical applications" don't use memory bandwidth,
then this guy is right. But stuff I care about is
often limited by memory bandwidth.... --PeterM
\_ Yeah, an easy test is to run Doom 3 or whatever and
measure fps, swap the memory to the wrong slots, and
see if there's a difference.
Repeat for real program that you're using. |
| 2005/11/5-8 [Computer/HW/Memory] UID:40453 Activity:nil |
11/4 I'm putting 1.5GB of RAM in a computer that takes PC2100. Is there
any reason that a mix of PC3200 and PC2700 RAM should not work?
\- kids today are lazy and stupid. STFW, the answer is obvious.
\_ Yes, the answers I found seems to say that it should work fine,
but with this RAM config, the computer now experiences kernel
oops, so I'm trying to figure out where to start with debugging.
\_ Have you tried loading your computer with this many sticks
of memory before? I'd be more suspicious signal integrity
or load problems first. That or even if your motherboard
is designed to support that memory configuration (assuming
yours is an older design).
\_ I have never had success mixing ram. Now a days I always order
from the same vendor and if possible the same part number. If
I can't I replace all the ram so it all matches. Linux/FreeBSD
seem to be far more sensitive to this than windows. |
| 2005/11/3-4 [Computer/HW/Memory] UID:40421 Activity:nil |
11/3 In Windows XP, how can I trace all the files called by an executable?
I'm trying to run Quicken off of my USB thumbdrive by doing this:
1. Installed a copy (I bought at Fry's) on XPProAtHome machine.
2. Copied executables to USB thumbdrive.
3. Used SysInternal's procexp.exe to see what files qw.exe used when
it was running on XPProAtHome.
4. Copied some additional dll's and other files that procexp.exe
highlighted to USB thumbdrive.
5. Copied additional dll's and other files to appropriate directories
on XPProAtWork machine.
6. Ran qw.exe off the thumbdrive using XPProAtWork.
7. Quicken hangs at splash screen.
Apparently, just copying the executables and additional dll's and files
is not sufficient. Procexpe.exe also highlighted some registry keys in
use on the XPProAtHome machine, but I haven't tried copying those to
the registry in XPProAtWork yet. Before I do that, is this even
feasible? I googled on 'tracing files called by executables' but the
results mostly relate to networking issues. Any help is appreciated.
\_ try filemon?
\_ Why not mount the drive then install onto it? Doesn't Quicken ask
where you want to install it?
\_ But it will still modify the registry of the target machine,
right? So will it run if I try to take it to another machine?
-op
\_ Oh, probably... why not just put your data files on the thumb
drive? Why do you actually need the bins there?
\_ Yes, I plan on putting my data files on the thumbdrive too.
I want to put the binaries on there so that I can run it
on any PC without having to install it on that PC. |
| 2005/10/13-14 [Computer/HW/Memory] UID:40072 Activity:nil |
10/13 Remember rapidly climbing memory prices? All the memory makers were
in on it.
http://www.cnn.com/2005/TECH/10/13/samsung.price.fixing.ap/index.html |
| 2005/10/8-9 [Computer/HW/Memory] UID:40025 Activity:nil |
10/8 In memory of the Rush, buried by Classes of '07 and '08,
March 23, 1905. Requiescat in Pace. |
| 2005/9/30-10/3 [Computer/SW/OS, Computer/HW/Memory] UID:39934 Activity:nil |
9/30 I've got a Via C3 (using kernel-image-2.4.27-2-586tsc) and 1504 MB
of RAM. Only 904 MB shows up with the "free" command. Is there a way
to get this kernel to see/use all the available ram? or do I need
a newer (or custom compiled) kernel?
\_ you need a kernel compiled with bigmem support, or something like
that. or highmem. i forget the exact term.
\_ Great! Thanks. I think I found it: CONFIG_HIGHMEM4G -op
\_ Great! Thanks. I think I found it: CONFIG_HIGHMEM -op |
| 2005/9/23-27 [Computer/HW/Memory, Computer/HW/CPU, Consumer/TV] UID:39841 Activity:nil |
9/23 Anyone ever built their own TiVo/PVR? any suggestions/advice
before I build one? I'm reading my way through http://byopvr.com
trying to figure out how to build one.
\- isnt the hardware heavily subsidized? why would you want
to build one from scratch? or is this a geek learning exercise?
\_ definitely the latter. granted I won't have to pay a
monthly service fee, I'll probably pay more up front
if I build one.
\_ I built mine out of mythtv because for some reason, I've
generally been against paying for a subscription of any kind.
You also get more features from building your own. Another
reason these days with TiVo adding various restrictions is
that you're not under direct control of some corporation's
whim. I admit, TiVo probably is more stable, but mythtv is
what works for me.
\_ How much did you spend on the hardware?
\_ I've used parts that are just laying about few times.
The latest incarnation I'm working on cost me about $400
for the shuttle-like case, cpu, and memory, I believe.
\_ I like to be able to watch recorded programs remotely :)
\_ You mean like mythtv?
\_ Decide on size of machine and noise level you find acceptable.
\_ how about those VIA C3 chip. I know that you can run
800Mhz without any fans. The newer 1GHz chip from
xxx nm fab reportly can run without fan neither. tried it? |
| 2005/9/21 [Computer/HW/Memory] UID:39800 Activity:nil |
9/21 What's the benefit of ECC RAM?
\_ When the RAM has a bit error it alerts you about it and
attempts to correct it. There is an extra 'parity bit' that
works like such bits do in RAIDs. Without ECC RAM you have no
idea if your data is corrupt or not. Always buy ECC RAM for
data you care about. I recommend always buying it if your
motherboard supports it.
http://www.anandtech.com/guides/viewfaq.html?i=3
\_ Is there EC RAM which you still have an idea if your data is
corrupt or not, although not being able to correct it?
\_ That would be called parity.
\_ There is. It's just called 'parity RAM' but I never see
it (or support for it). It seems ECC has rendered plain
old parity RAM obsolete.
\_ See, it works like this: if you have only 8 bits
in your RAM line, (RAM stored by bytes), you can
add a chip and get 9 bits: 8 data, and parity.
If you have 32 bits in your RAM line, you can add 4
bits and do ECC on those 32 bits. So ECC RAM is
party RAM, it's just stupid not to do ECC since you
have 4 bits per 32 instead of just 1 per 8. All RAM
these days is at least 32 bits "wide", so everyone
just does ECC.... --PM
\_ Yes, but you can still just 'check' the data and
not correct it, but why do it when ECC is so much more
useful and can check 2 bits (and correct 1) instead of
just checking 1?
\_ the idea is that the more parity bits you have,
the higher you probability of catching the error.
with only 1 bit, you'll not catch anything. with
4 bits, you catch more. but with 4 bits, you
might as well correct as well.
\_ Why can't I catch 1-bit errors with 1-bit parity? |
| 2005/8/9-11 [Computer/HW/Laptop, Computer/HW/Memory] UID:39064 Activity:nil |
8/9 I had a motherboard die after like 90% of the capacitors leaked.
Appareantly this is a widespread problem (badcaps.net). I'm
wondering, (a) why I hadn't heard of this earlier, and (b) why
there hasn't been a big recall of defective components.
\_ (a) because you don't read /., http://theinquirer.net, .... Do you
read anything? Try to keep up a little, will ya? This is
over a year old stuff.
\_ I read /. almost everyday. When was it on /.?
\_ Years ago.
(b) Abit sort of recalled. Problem is too widespread to recall.
Trying to do so would probably take out a lot of companies.
\_ Not only that, you apparently don't read the MOTD or archives,
this was mentioned more than once here. The answer is to get
replacement caps (assuming your other components are intact)
and solder them on to the board. Also, MBs are under $100 US,
the cheapies can be found for sometimes less than fifty, so
it's such a cheapie item that a general recall would've killed
some of the MB companies because the margins are razor thin.
And yes, there is a sort-off coverup going on.
\_ I just had my thinkpad t41 crap out under warranty... does anyone
know if they had this problem too? It died slowly, e.g. showing
signs of going out of spec in the video memory first.
\_ Just about EVERY company was affected, including IBM. |
| 5/16 |