Seeking explanation for 512MB 'NVCACHE' partition entry

Discussion in 'Windows Vista Hardware' started by a.k.a., Dec 27, 2007.

  1. a.k.a.

    a.k.a. Guest

    Greetings, everyone!

    There's a mystery drive partition on my system. Can anyone please confirm
    what it's used for/by?

    I'm running a triple boot of Server x64 RC2, Vista x64 SP1 RC, and Vista
    x86, installed on two internal hard disk drives. These are SATA drives, but
    not hybrids. They both have 8MB caches. (One is a Samsung HM250JI. The other
    is a Hitachi TravelStar 7K100.) I also have 1GB of Intel's Robson NAND.

    Now, in Disk Management, a 513MB (sic) FAT32 partition is there, called
    NVCACHE. It's listed as its own HDD, sandwiched between HDD 0 and HDD 1.

    So, there are two possible explanations as far as I can see:

    1st candidate explanation: There's an Intel page that discusses Turbo
    Memory, which uses the "NVCACHE" term when describing its support for Vista
    ReadyDrive and "T13 specification Command Handling," which I had assumed
    applied just to hybrid hard drives, not to regular HDDs.

    The other thing that's fishy is the 513MB cache size. Where'd the remaining
    511MB go if this system has a full 1GB Robson NAND? Was I gyped out of 512MB
    of NAND?

    2nd candidate explanation: This has something to do with the SATA caching
    functionality that I have enabled in the x86 partition. [See: Device Manager
    -> Disk Drives -> right-click on a SATA drive -> Properties -> Policies ->
    Enable Write Caching on the Disk -> Enable Advanced Performance.]

    If that's the purpose, then the question is: Do I need to confine my use of
    the SATA cache to one OS installation, or am I safe to enable this function
    in all of the OSes simultaneously? (Will overwrites by different OSes of each
    others' caches destabilize the system or not?)

    Thanks for sharing your insights.
    a.k.a., Dec 27, 2007
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  2. a.k.a.

    a.k.a. Guest

    Here we go, suffering the embarrassment of replying to one's own post....

    NVCACHE appears to be part of the Intel Turbo Memory setup. My chip is 1GB
    NAND RAM, so it makes no sense to me why it's set at a 513MB cache. Plus,
    it's giving me the problem that folks with 512MB chips encounter: ReadyBoost
    won't turn on, even with the latest driver.

    See this post for more info about the cache:

    a.k.a., Jan 5, 2008
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  3. a.k.a.

    andreaacme Guest

    Yeah, same here. I have a ASUS G1S notebook and has 2GB RAM + 1GB
    IntelTurboMemory. When all system files and drives are forced to be
    shown, I can see a NVCACHE drive of 512MB showing and TurboChache is
    enabled only for 490MB (also when setting Cache value in "ReadyBoost
    enable" it recommened me to set 450MB. I think there is something
    wrong but if other people have the same .... maybe it isn't abnormal.

    Please help us understand more, spread the knowledge! :)

    andreaacme, Mar 2, 2008
  4. a.k.a.

    andreaacme Guest

    Ok I did it too a.k.a. .... I will reply to my own post and spread
    the knowledge.

    Windows ReadyDrive enables computers shipped with a hybrid hard drive
    to access data from the nonvolatile cache, allowing the disk to remain
    spun down for longer periods of time.
    Windows ReadyBoost allows nonvolatile flash memory devices, such as
    USB flash drives, to be used as an additional memory cache in order to
    improve system performance without the addition of more system memory.

    If the Intel® Turbo Memory module is 512MB, only Microsoft Windows
    ReadyDrive is supported; you will not be able to enable Microsoft
    Windows ReadyBoost.
    If the system has an Intel® 82801IR I/O Controller Hub (ICH9R),
    Microsoft Windows ReadyDrive is not supported.

    This is general knowledge and as a deduction comes the answer.

    512MB are used by ReadyBoost and 512MB are used by ReadyDrive. One of
    the two is visible as a physical drive (NVCACHE) and the other isn't
    but if enabled by its utility (Intel® Turbo Memory Console) it will be

    A note on performance increase.
    If the system you are running has low amount of RAM (ie. 1GB) then
    using an IntelTurboCache module of 1GB will yield a noticable
    performance increase, but if the system already has a fair amount of
    RAM (ie. >=2GB) then the increase will not be noticed as much and
    going over 2GB IntelTurboCache will be just a waste of money. Beware
    when using non-internal Cache (ie. a USB2 StickDrive or similar), the
    Cache should perform better than 10MB/s reads.

    Okee that's all for now.

    andreaacme, Mar 2, 2008
  5. a.k.a.

    a.k.a. Guest

    Andy, you wrote:

    "512MB are used by ReadyBoost and 512MB are used by ReadyDrive. One of
    the two is visible as a physical drive (NVCACHE) and the other isn't
    but if enabled by its utility (Intel® Turbo Memory Console) it will be

    Yeah, ok, but my question was, why is mine saying 513MB? What's up with that
    extra 1MB?

    Just kidding.

    Well, that's a very logical explanation that 512 goes to RD and 512 to RB,
    and I'll just take that as the final word. Is it an answer you read
    somewhere, or did you just deduce it, as you implied?

    Many thanks. Now I won't be counting sheep tonight....

    a.k.a., Mar 3, 2008
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