Berkeley CSUA MOTD:Entry 50014
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2008/5/20-23 [Computer/SW/OS/Linux] UID:50014 Activity:nil
5/20    Q: Which is faster, a 146GB 15K RPM SAS disk or a 300GB 15K RPM
           SAS disk? I read that a larger drive is faster (more density
           means more data at hand) and also slower (more area to
           traverse). So which is it?
        \_ http://Storagereview.com will a) provide you tons of raw data and b) show
           you that there are different kinds of fast.
           \_ Thanks. Short answer: Bigger is better.
              http://tinyurl.com/587y3w
              \_ boobs, penis, cars, what else?
                 \_ Paychecks, wallets.
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tinyurl.com/587y3w -> faq.storagereview.com/tiki-index.php?page=CapacityPerformance
similar Access time is possibly the biggest factor that affects a drive's performance. Access time = rotational latency + seek time Capacity can be thought of as a way of attacking seek time. If you have a 20 GB drive and you have about 10 GB of files on your drive, you will have to seek across 50% of the platter to access two files at "opposite ends" from each other. The precise formula for how extra capacity translates into additional performance is up for debate, but IMO, you get on average 7-10% better performance for every doubling of capacity. We know areal density often translates directly into higher STR, but what does it do for access time? If you think about it, it is a way of attacking both rotational latency and seek time. It achieves this because higher areal density is the product of additional linear bit density or sectors per track (spt) and tracks per inch (tpi). So, given the same amount of data, a higher density platter will be able to pack more information linearly along a track, resulting in more files being covered with each rotation. A higher density platter will also be able to pack more information across the platter, so that the heads don't have to seek as far to cover a given amount of data. However, areal density often manifests itself in the additional capacity of a newer drive.
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Storagereview.com
Fujitsu's Newly-Announced SCSI Drives 08 March 2004 Fujitsu today announced a refresh of both its 10k and 15k RPM SCSI lines, the second step (following Hitachi's announcement of its Ultrastar 10K300) in a long-awaited update in SCSI densities and capacities. The 10,000 MAT series combines up to four platters to yield a flagship capacity of 300 gigabytes while the 15,000 RPM MAU pushes up to 147 GB. Fujitsu will finally incorporate FDB motors across the board, hopefully combining reduced noise levels with the firm's top-rate performance. Hitachi Global Storage Technologies (formerly IBM storage) is once again first out of the gate, this time offering a 300 GB 10K RPM drive, the Ultrastar 10K300. Like the previous Ultrastar 146Z10, the 10K300 achieves this high capacity by incorporating five rather than the more standard four platters in the flagship unit. The drive incorporates FDB motors, which will hopefully attentuate the line's previous penchant towards very high idle noise levels. Miscellanea 20 February 2004 This week yielded a couple interesting developments on the hard drive front. The first was Seagate's official announcement of their 25" Savvio line. The benefits, of course, are numerous- lower access times via standardization of smaller platters, less heat and noise due to the physically smaller size, cost savings via both less consumed material and less required physical space to store large arrays of disks, etc. Many readers have noted the distinct lack of advancement (capacity-wise) in the enterprise domain. The traditional fourth quarter of last year, for instance, passed with conspicuous silence as no major new units were announced. A combination of technological hurdles with somewhat tapered-off demand. And, while the maximum capacity per unit hasn't increased in a while, consider that one can fit several 25" Savvio drives in the same space that one 35" Cheetah occupies. That said, we're told larger disks in the traditional form-factor will appear this year. On another front, SR has never taken an official stance regarding the IBM Deskstar 75GXP reliability issue. Witness, for example, the amount of posters in both SR's community as well as others decrying a given family or brand based on a single experience. Ruminations over at Tech-Report, however, indicate that documents uncovered in the ongoing class-action lawsuit against the firm provide the most concrete evidence yet that the 75GXP suffers from serious problems. The Raptor Review 28 January 2004 A preview late last year of Western Digital's next-generation Raptor indicated world-class non-server performance coupled with the future promise of competitive server scores through the introduction of tagged command queuing. The WD740GD has hit the channels and been readily available for a bit. We've spent the past 36 hours uploading our last daily backup at a painfully slow pace. Most of the data is in place- all site features except the forum (the database of which is having tricky problems with MySQL3) and features that depend on the forum login (the reliability survey and reader polls) should be up and running without a hitch. Importing the forum database is a bit more complicated since RHE3 includes (sigh) MySQL3 while the forum database was powered by MySQL4. Though MySQL's site states that v3 can accept dumps generated by v4 without a hitch, practice, as usual, has been different (Update 3:35 AM: MySQL4 upgrade complete, forums operational).