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The CF/SD Performance Database is a regularly-updated compilation of write and read speed test results designed to aid the serious and professional photographer in selecting camera storage media for a Canon or Nikon digital SLR. Write speed test results for each of the digital SLR models actively being tested, as well as card-to-computer transfer rates, can be accessed from the popup menu above.
Defining performance A memory card is a critical component in the professional photographer's digital system. We hope that the CF/SD Performance Database will, first and foremost, enable you to determine which cards offer the speed your workflow requires. But we encourage you to look at card performance holistically. While speed is important, so is the warranty, tech support and reputation of the company whose name is on the label. Though you may have come to this database to see how CompactFlash and SD/SDHC cards perform in your camera, we think it's equally important these days to consider card-to-computer transfer rates. That's because in our own workflow, the time it takes for photos to transfer to the computer is often a bigger bottleneck that in-camera write speed. As both cards and card readers get faster, we expect that card-to-computer transfer speed will become even more significant a factor in the card selection process. An introduction to CompactFlash and SD/SDHC technology There are two sizes of CompactFlash. CompactFlash Type I (right) All of the CompactFlash-capable cameras in the database accept both CFI and CFII. SD is short for Secure Digital, and there are two variants of it on the market: SD and SDHC (Secure Digital High Capacity). The differences between the two are on the inside, as they are the same physical size and have the same connector arrangement. SD cards are limited to a maximum capacity of 2GB (there are a handful of 4GB SD cards out there, but they don't work in all cameras and card readers), while SDHC cards, as defined in the current specification, top out at 32GB (the maximum theoretical limit is 2048GB). Older SD-capable cameras and card readers that shipped before the advent of SDHC will not be compatible with SDHC, unless the manufacturer released a firmware update to introduce SDHC compatibility. Newer gear that supports SDHC is backwards-compatible with SD. The Nikon D50 is the only SD-capable camera in the database that isn't compatible with SDHC. Though there are a myriad of brands on the market, most larger-capacity CompactFlash and Secure Digital flash memory cards contain controllers from SanDisk, Lexar and a number of lesser known electronics companies: Hyperstone, KTC, Skymedi and SMI, to name a few. Flash memory cards contain, in addition to a controller, several flash memory chips. Toshiba, SanDisk and Samsung are among the biggest flash memory chip suppliers (Toshiba and SanDisk are also partners in the manufacture of flash memory). Almost all the companies included in the database purchase flash from one or more of these companies (or use their own if they're an industry heavyweight like SanDisk), for inclusion in their products. The controller and the flash memory together determine the raw performance of the card. In 2008, the NAND-type flash memory used in CompactFlash and SD/SDHC is fast, really fast; it's the controller currently that has the biggest impact on card throughput.
We compete with semiconductor companies that manufacture and sell flash memory chips or flash memory cards. These include Hynix, Infineon, Micron, Renesas, Samsung, SanDisk, ST Micro and Toshiba. Micron and Intel have recently formed a joint venture known as Intel Micron Flash Technologies. SanDisk and Toshiba jointly develop and manufacture both low-cost and high-performance flash memory through their Flash Vision joint venture.
We also face significant competition from manufacturers or card assemblers and resellers that either resell flash cards purchased from others or assemble cards from controllers and flash memory chips purchased from companies such as Renesas, Samsung or Toshiba, into flash cards. These companies include Crucial, Dane-Elec, Delkin Devices, Feiya, Fuji, Hagiwara, Hama, Hewlett Packard, Data I/O, Infineon, Kingston, Kodak, M-Systems, Matsushita, Memorex, Memory Plus, Micron, PNY, PQI, Pretec, Ritek, Samsung, SanDisk, Silicon Storage Technology, SimpleTech, SMART Modular Technologies, Sony, TDK, Transcend, Viking InterWorks and many others.
In addition, an increasing number of companies are manufacturing their own controllers, including Genesys, Hyperstone, Prolific, SanDisk, Sigmatel, Silicon Storage Technology, SMI, Solid State System, Sony and Zoran. Such companies either combine their controllers with flash memory from third parties to manufacture their own flash cards or sell their controllers to third parties who use them to assemble flash cards. Additionally, major semiconductor companies such as Infineon, Micron, Renesas, Samsung and Toshiba have also developed or are currently developing their own controllers that will likely compete with our controller and/or card sales.
We also face competition from some manufacturers of traditional film products. Kodak and Fuji are the largest and best-known manufacturers of traditional film products. Fuji has entered the flash card market, but does not yet manufacture its own flash cards. In 2004, we entered into an agreement with Kodak to sell flash cards under the Kodak brand on a worldwide basis.
Several companies, such as Cornice, IBM, and Matrix Semiconductor, which was acquired by SanDisk in 2005, have introduced competing technologies for use in digital cameras. These include products such as Digital Capture Technology and the MicroDrive. Technical background If a CompactFlash card is designed to hold data, then it's either a miniature hard drive or flash memory inside. Miniature hard drive cards have been around for a long time, at least in computer years: early digital field photographers (ie: those who were shooting digital in the early 90s) will remember the 85MB Maxtor PC Card hard drive as being THE card to get. Miniature hard drives operate much like their larger counterparts: to write a photo, a tiny arm swings over a rotating platter, encoding small areas on the platter with zeros and ones as it goes. Today, there are a handful of miniature hard drives in CompactFlash form, including the Hitachi Microdrive and Seagate's Photo Hard Drive, but they have now been surpassed in capacity, performance and price/GB by flash memory-based CompactFlash. Zeros and ones are stored in memory cells, instead of on a rotating platter. There is a key difference, however, between computer RAM and the memory chips used in digital camera cards: digital camera cards contain non-volatile RAM. That means photos aren't purged when the card is removed from the camera. Instead, memory cells remember if they contain zeros or ones until told otherwise. The greater the number of memory chips, and the more densely packed each memory chip, the greater the capacity of the card. Card capacities have been increasing as flash memory manufacturers have devised new ways to shrink memory chips. As of early 2008, 32GB CompactFlash cards were shipping, with SDHC cards of the same capacity expected to be released in the next few months. Both flash memory and rotating hard drive cards contain a controller. The controller determines how data is to be written to and read from the memory on the card. Whether a flash memory card or a card like the Hitachi Microdrive will be speedy or not with a given camera is determined as much as anything by the controller architecture. A card that is fastest with one camera isn't necessarily fastest with another, because of how the controller interacts with and exchanges data with the camera. The flash memory itself determines the maximum speed of flash memory cards, since no matter how efficient the camera-controller communication, data can't be transferred to the card any faster than the flash memory is capable of receiving it. Part of the price premium charged for certain fast flash memory cards reflects the extra cost of using the fastes...
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