The Performance Equation

USB flash drives are really quite simple devices. There are three parts to each USB drive that can actually impact performance: the flash controller, the flash memory itself, and the PCB on which the former two items are mounted. We're not talking about extremely high speed transfer rates here, so layout isn't as difficult or critical as it is with things such as motherboards, but it is a factor in influencing performance, albeit the least visible one.


Pictured here is the PCB of a USB flash drive. The left-most chip is a Samsung NAND flash device, and the other chip is a USBest flash controller. The connector on the right is a standard USB connector.

The problem with USB flash drives, however, is that the controller and the flash memory are rarely constant within the manufacturing of a single drive. In order to keep costs down and maintain a steady supply, most manufacturers obtain their controllers and memory from multiple sources, so buying one drive doesn't necessarily mean that you'll get the same combination of controller and memory that we test here.

Luckily, for the most part, this only applies to the lower end and mid-range flash drives. Even then, manufacturers guarantee some minimum level of performance, generally described somewhere on the packaging itself. But because of this variation in chip suppliers and/or types, performance will vary more than what we're used to between models of the exact same product. The higher end performance-optimized drives don't usually have this problem because the manufacturers put performance on a higher pedestal, thus they will always choose the same high performing chips to be used in these offerings. The manufacturing quantities are also much lower for the high-end, high-performance units, so having multiple sources for the controller and flash memories isn't as important.

Not only do manufacturers use different controllers/flash memories for the exact same product, but they do so at various storage sizes of that product line. For example, a 512MB USB flash drive from Company X may use a completely different controller than a 2GB drive of the same product family. Obviously, the flash memory itself is going to be different across different storage sizes, but do keep in mind that unlike hard drives, greater storage density does not necessarily mean greater performance; in other words, although different sized drives may perform differently, it isn't because of the size of the drive, but rather the actual components used on that particular drive.

There are a number of cases where the 512MB versions of a particular USB flash drive are faster than their 1GB and 2GB brethren, and other cases where the opposite is true. So, while we did our best to compare performance of equal sized drives in this roundup, note that the performance that you'll see here doesn't always map to larger drives. It is worth mentioning that although different sized drives do perform differently, the differences in performance are usually not enough to change dramatically the performance standings that you'll see in our charts.

Index Dual Channel Flash Drives
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  • phisrow - Tuesday, October 04, 2005 - link

    I'm glad to have some idea about real world performance specs, to the degree that the volatility of the market allows that, of these drives. Any chance that this, or future, reviews of this kind could test making the drives bootable. Some are easy, some are impossible, and some need some real voodoo to get them working. I'd love to know which is which these days. Reply
  • johnsonx - Tuesday, October 04, 2005 - link

    Page 13:

    "although, neither is obviously full-proof."
    Reply
  • yacoub - Tuesday, October 04, 2005 - link

    "From top to bottom, a AA battery, Kingston DataTraveler II drive, Kingston DataTraveler Elite."

    No, not even close.
    Elite is on top, DT2 is next, AA battery next, and 9-volt battery on the bottom.
    Reply
  • TheInvincibleMustard - Tuesday, October 04, 2005 - link

    C'mon, I soooo posted that before you!

    :p

    -TIM
    Reply
  • yacoub - Tuesday, October 04, 2005 - link

    What's with all the scratches on the Corsair Flash Voyager's USB connector? Reply
  • TheInvincibleMustard - Tuesday, October 04, 2005 - link

    I was actually wondering that, too ... what did you do to that poor thing to take the cover off???

    All in the name of science, eh?

    TYPO: Pg 13 ... the caption for the "battery" picture doesn't correspond to the actual picture ... oh ... and just how OLD is that 9V Eveready? It looks like something out of the stonage in comparison to the other things in the picture ...

    -TIM
    Reply
  • SpaceRanger - Tuesday, October 04, 2005 - link

    Stonage?? Sorry.. Couldn't help pointing out a typo in a "typo informative" post..

    /em hides now.
    Reply
  • TheInvincibleMustard - Tuesday, October 04, 2005 - link

    :p

    And that's all I hafta say about that.

    -TIM
    Reply
  • sxr7171 - Tuesday, October 04, 2005 - link

    Time to get a Lexar JumpDrive lightning. This may not be important to a lot of people, but a USB drive IMHO needs to have a loop for a keyring. It is the most convenient way to carry the thing and always have it with you no matter what. I guess this applies more to people living in the city and not needing a car and the big bulky car keys/remote that come with that. Reply
  • TheInvincibleMustard - Tuesday, October 04, 2005 - link

    Speaking of, is there some reason the Lexar isn't on the RTPE? I mean, it did just win an Editor's Choice and all, so you'd hope it would be one of the drives listed in the newly-announced Flash Storage section ... :(

    -TIM
    Reply

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