Dual Channel Flash Drives

With flash drives, the fewer chips you use, the smaller your device can be and the cheaper it can be as well. It is almost always cheaper for a manufacturer to use one 4Gbit flash device than to use two 2Gbit devices, so as long as there is a high enough density available, you would expect manufacturers to always opt for a single chip flash solution (at least for the memory). Lately, however, some controller manufacturers have offered "dual channel" controllers that allow you to read from/write to multiple flash devices simultaneously; think of it like RAID-0 for flash drives.


A multi-channel USB flash drive; note the presence of two flash devices to the right of the OTi controller.

Most USB flash controllers feature a single 8-bit wide interface to their flash memory, but a dual channel controller features a 16-bit wide interface and can read from/write to two flash devices at a time. Most NAND flash devices used in these drives have a 2112 byte page size, so whenever data is written, it is done in 2112 byte chunks. For a dual-channel device, all data reads and writes are effectively striped across the two memory devices, much like in a RAID-0 array.

The performance boost for a dual channel drive over a single channel drive depends a lot on the type of flash used as well as the controller itself. In many cases, however, a dual channel drive can be up to 2x as fast as a single channel drive.

Most physically larger drives that are branded as high performance drives are dual channel solutions, even if they aren't marketed as such. The cheaper drives end up being single chip/single channel, and of course, the small form factor drives end up being single chip/single channel as well.

The Performance Equation USB Flash Drive Security
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  • LightRider - Tuesday, October 4, 2005 - link

    Page 22 Shikatronics Manhattan

    quote:

    The drive ships with a lanyard and a USB extension cable, which makes the cap issue less of a hindrance
    USB Extension Cable Included No
    Data Encryption No
  • LightRider - Tuesday, October 4, 2005 - link

    Of course I make an error in my post pointing out an error...
    quote:

    Lanyard Included No
    USB Extension Cable Included No
  • phisrow - Tuesday, October 4, 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.
  • johnsonx - Tuesday, October 4, 2005 - link

    Page 13:

    "although, neither is obviously full-proof."
  • yacoub - Tuesday, October 4, 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.
  • TheInvincibleMustard - Tuesday, October 4, 2005 - link

    C'mon, I soooo posted that before you!

    :p

    -TIM
  • yacoub - Tuesday, October 4, 2005 - link

    What's with all the scratches on the Corsair Flash Voyager's USB connector?
  • TheInvincibleMustard - Tuesday, October 4, 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
  • SpaceRanger - Tuesday, October 4, 2005 - link

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

    /em hides now.
  • TheInvincibleMustard - Tuesday, October 4, 2005 - link

    :p

    And that's all I hafta say about that.

    -TIM

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