How-To Geek

Speed up Your Windows Vista Computer with ReadyBoost

Windows Vista includes a new feature called ReadyBoost that lets you plug in a flash memory stick or SD card to store commonly used files for quicker access than off the hard drive.

Turning this feature on couldn’t be simpler. Just stick the flash drive, SD card, or whatever flash device you want into your computer. You’ll see this dialog pop up:

Click the “Speed up my system” link, and you’ll be taken to the ReadyBoost panel for the flash drive:

Just select Use this device, and set the amount of space you want to use. Windows will create what is essentially a paging file on the disk, and will use it for faster access.

Note that this will only work with USB 2.0 devices or SD cards.

Lowell Heddings, better known online as the How-To Geek, spends all his free time bringing you fresh geekery on a daily basis. You can follow him on if you'd like.

  • Published 01/8/07

Comments (75)

  1. Ben

    Hi. I’ve tried using two different USB 2.0 flash memory sticks to boost the system but each time vista tells me that the drive doesn’t have the performance characteristics to allow it to do this. Both drives are USB 2.0 and I have tried them in different USB ports. Do you have any suggestions? Thanks.

  2. Al

    Ben, I’d make sure your motherboard supports 2.0, and your bios has USB 2.0 enabled. It’s possible for a 2.0 board to have 1.0 slots, so make sure you are using the correct slot.

  3. Bryan

    Make sure that the flash drives you are using are rated at the high-speed category. I do not think that full speed is sufficient.

  4. Notebooks

    This won’t work with all flash drives and SD cards. They have to be of the high-speed variety. Look for the ReadyBoost certification when you’re shopping for cards. None of the bargain basement cards are fast enough for ReadyBoost.

  5. Ben

    Thanks, I appreciate the help. The motherboard does support USB2 and the bios Is USB 2 enabled. The memory sticks I’ve tried are all high speed. Still does not work with ready boost however. do you have any other suggestions I could use?

  6. Dragme2u

    Are these USB Drives formatted with NTFS. If not then format the same with NTFS and then try.

  7. Todd

    Be carefull when buying SD cards because all the cards from PNY say “ready for windows vista upgrade” and that DOES NOT mean that it will work with readyboost. I just bought one and assumed since it said “windows vista upgrade” on the front that it would work with readyboost and it doesn’t. So I’m a little ticked at PNY right now because that is very deceiving.

  8. CaptainStupid

    I have the same problem. I formatted my 2GB SD card as NTFS, but Windows Vista still says, “This device does not have the required performance characteristics for use in speeding up your system.” How fast is high-speed? The specs for my card say it has a transfer speed of 10MB per second.

  9. K Henderson

    If you google around at hardware tech review sites, you’ll see that you dont want to use readyboost. USB RAM is not faster than system RAM. You are better off buying more internal system RAM if system speed is a concern.

  10. Myagi

    You must buy a readyboost certified device for it to work, but i came across a webpage which my link is broken to that shows you how to do some registry tweaking that allows you to use any USB thumbdrive even if it is not readyboost certified, not as good but still efficient if you have one lying around. I use readyboost all the time and it helps a lot, but it is no substitute for system memory but when i play games or doing something that is heavy load i pop it in and it helps

  11. nuckz

    I’m using a USB 2.0 1GB stick I purchased way back in late 2004 and it works perfectly as readyboost device. I agree there is no substitute for buying more system memory although I’ve found since upgrading to 2GB, it doesn’t make that much of a difference, in speed just the number of applications you have open.

  12. mrogi

    I’ve got a VoyagerGT flash drive. I looked at the Readyboost Operational logs in Event Viewer. The logs contain no speed results even though my flash drive is Readyboost enabled and functional. How can I manually generate a Readyboost speed test in Vista?

  13. Rahul


    I have a 2gb pen drive, I want to know If i use this for ready to boost, does this mean i have to keep the pen drive plugged everytime i use the computer or i can remove it and still use the pc

    If i want to later use it to store files can I safely format it?
    or i need to transfer back everything to the pc?

  14. Adam

    To Todd and all others, you have no one to blame but yourself. “Vista certified” or “Ready for Vista Upgrade” is just a gimmick that some hardware (that are vista compatible regardless) brands use to hype up their product. All of the following are designed specifically for ReadyBoost ( ). Stop blaming companies just because you like to jump to conclusions.

  15. Jesse

    To everyone, I had the same problem, Vista said it wasn’t fast enough, but then i clicked “retest” and it worked fine.

  16. Kevin

    Dude it sucks to have one that dus not work since i have onley tried 5 diferent brands and thay work fine for me. Tho i am right now just going to try a sd card for the first time home it works since its a hc 150x

  17. whs

    I have used Ready Boost on 2 different laptops. One with 1GB of RAM and one with 2GB’S of RAM. I used flash drives (2GB and 4GB) that were specified as “Ready Boost enabled”. My experience is that there is hardly any noticeable performance advantage. In some regard, it is just the opposite. E.g. restarting Vista seems to take longer. It apparently makes some setups on the flash drive that takes extra time. I have taken it out and bought 2 GB’s of RAM for the 1GB laptop instead. That works a lot better and at $60 for the extra 2 x 1GB Dimms it is only slightly more expensive than a high speed flash drive of 2 GB’s.

  18. Anuj Purohit

    SDHC or MMC + (Plus) can be used for ReadyBoost

  19. Aaron

    Hi everyone does anyone know if you can have two memories using ReadyBoost

  20. Brent`

    ************** RE-FORMAT THE DRIVE USING NTFS FORMAT (4k) ********************

    The factory usually formats the flash drive as FAT32. FAT is a good name for this format beause it’s slow and eats alot of bus time. NTFS is the way to go!! It requires a little more Flash memory for this format (35 Meg on a 4 Gig flash as oppossed to 4K for FAT32, but it’s well worth it. I’ve only been able to NTFS format a Flash Drive on a Vista machine, but it is AMAZING !! Your new Drive is now quicker than ever for both XP and Vista…..and it’s now fast enough to try it as “Speed Boost” on Vista. Don’t have much info on perfomance of that function yet, but……….now, you have something you can really call FLASH !!


    that is all a vista ready flash drive is it is no special rocket scientists thing

  21. mrogi

    According to Kingston Memory tech support, dont reformat the USB flash drive. FAT 32 is just fine for Readyboost.

  22. Brent`

    Well I work for ATI Canada and with a majority of the good flash drives that are produced for Vista ready boost they are flashed NTFS your tech should now that fat 32 doesn’t work well with NTFS FAT is slow to slow for ready boost

  23. Kevin

    I have found latley that people have hade trouble with ready boost not working with suported devices even. so i did some studeys and test and found that certin usb ports are varrey slow and that is wi readybost will say the device duz not have the performance. A lot of that is du to drivers that even tho sighned for windows the chipset on the usb controller actuley is not fulley compatable. you get this on a lot of systems that have ben upgraded frome windows xp to vista. Now thare is a way to force readyboost to work but it usley slows your system.

  24. Kevin

    You can alwez buy a secend small harddrive install it in your system and use it as a page file drive onley and that is actuley faster then readyboost.

  25. mrogi

    Yo Kevin, no offense, but it is hard to take technical advice from a guy with the writing skills of a 2nd grader.

  26. Jakes

    If anyone still cares, I ran a checkdisk (ticked fix errors etc) on my 2GB flashdrive that apparently did not have the speed for readyboost – after the checkdisk I retested it and it was good to go?

  27. Howard Woodard

    Yesterday I bought a 4 gb flash that was marked as Ready Boost ready. I plugged it in, it installed the driver and then I selected “Speed up my system” on the auto start dialogue box. It then brought up the ReadyBoost tab from the device properties. It had two selections (use this device or don’t use this device) along with a slider to indicate how much of the drive I wanted to use. I left the defaul setting (use all of it). It seemed to work fine. I could see the led on the flash drive flicker along as I used the system.

    This morning I noticed that the drive came formatted for FAT32. After reading the help file on partition formatting, I converted it to NTFS and restarted my system. Then I noticed that the led was simply holding steady. I went in and looked at the properties and and found the message “This device does not have the required performance characteristics for use in speeding up your system”.

    I’ve tried everything, including a system restore and starting over, reformatting back to FAT32, re-testing, etc. but nothing changes. Vista just doesn’t think the drive is fast enough anymore.

    I think it has something to do with the formatting itself but am not willing to spend another $20+ finding out. I’d be interested in the link that an earlier writer referred to that gave a Registry tweak to force the use.

  28. Bob

    Well, folks. I reformatted my 4 GB drive (which had been working just fine for ReadyBoost) in an attempt to expunge the dreaded U3 System software (SanDisk Cruzer, if you must know). Reformatted it as FAT32, and since then it has NOT functioned for ReadyBoost at all. Too boot it acts as if the drive is “too full” to accept any ReadyBoost dedicated space. I’m in the process of reformatting it as NTFS to see if it helps…I’ll let ya know what happens after that.

  29. Bob

    Well, the short-term follow-up is that after reformatting the drive as NTFS and plugging it back in, it immediately recognized the drive and Vista presented me the option of using the drive to “speed up my system”. So, I’ve used 3700 MB of it for ReadyBoost and will try something creative like opening up a zillion pdf files at once to see how it handles it.

  30. Bob

    OK. Third and (I expect) final post about format of the drive and ReadyBoost… for those of you in need of a recap, I had a 4 GB SandDisk Cruzer that had done wonders to speed up my Vista laptop, but had reformatted it as FAT32 in order to try and get rid of the annoying software that came with it. Once that happened it ceased to function for ReadyBoost (drive light stayed on all the time; Vista showed it as being too full to allow any dedicated space for ReadyBoost, adn the system was its usual slow dog self). I just reformatted it as NTFS (full format, not the Quick formatting option) and a) it was immediately recognized as Ready Boost ready when I plugged it back in, b) the light now flickers when it’s being accessed, and my system is faster than a speeding bullet once again. The empirical test was to open 27 PDF files at once. Took less than 30 seconds to open and display them all simultaneously, and 7-8 seconds to close all those PDF windows. This is pretty much how it functioned when I first started using it, and the same test. Shazaam! I’d say that FAT32 is “BAD” for ReadyBoost, and NTFS is “GOOD”. Hope this helps someone out there!

  31. Brian

    FYI for everyone, if you use a SD card, reformat it to NTFS and select compress drive, this will allow for using almost any SD for ready boost.

  32. HBG

    Why has this not been commonly made to registered users. My 4 year old LG notebook ran faster with the same amount of ram.

  33. Brian

    HBG, I am not sure why it is not known, I actually just figured it out playing around. Sure hope this helps, after all this forum has helped me ALOT with my vista issues. Have a great day!

  34. Eranga

    This forum helped me with the readyboost. I got the same messege saying that device doesnt have the required performence for readyboost. I ran a checkdisk (ticked fix errors) like Jake have mentioned above and retested my 8gb drive. It worked out fine.

  35. ijas

    i am using kingston 16gb pendrive , is it possible to do the operation(ready boost) using this pendrive . I have tried many times buts its responding as though it is not supported .
    How can i format a pendrive to make it NTFS format

  36. jan

    I ‘ve read that if you’re using “Readyboost” then you need to enable “Superfetch” in VISTA services as well … is this true?

  37. Nick Prignano

    FYI – I ended up on this post because I was looking for answers to why my Kingston DataTraveler 2.0 1GB RAM did not meet the specs for readyboost, when it clearly should have based on the manufacturers specs. The steps I took to make it work: 1) reformat to NTFS 2) select “Compress this drive”. After doing both, I switched to the readboost tab and it was now acceptable for readyboost.

  38. mrogi

    Test your Readyboost flash drive speed. Paste the first command into Start Menu Run box to test read speed. The second command tests write speed. Replace E with the drive letter of your flash drive.

    cmd /k winsat disk –read –ran –ransize 4096 –drive E

    cmd /k winsat disk –write –ran –ransize 524288 –drive E

  39. amcbeth

    I had the some problem with a Kingston 2 GB. I tried formatting with ntfs, checkdisk, and nothing worked. I was about to give up until I compressed the drive and BINGO. Is that weird? By the way mrogi, I tried your commands and the results were wiped off the screen. How can I get them to stay up there until I’ve read them. Also what’s good and what’s bad? In other words if I had the results what would I do with them?

  40. Tolly

    Almost the same as Nick Prignano’s.
    Kingston DataTraveler 2.0 2GB RAM did not meet the specs for readyboost, The steps I took to make it work: 1) reformat to NTFS 2) select “Compress this drive”. After doing both, I switched to the readboost tab and it was now acceptable for readyboost.

  41. Laura

    I found this page after SanDisk tech support advised returning my Cruzer to the store. Readyboost was working before I called them but I had another problem. Their solution was to reformat the flashdrive. After doing so, my other problem was solved but Readyboost gave an error about the device being below the min performance specs. The tech decided that the device must be defictive.

    Or Not.

    The simple solution was to hit “retest.” It took two tries.

    For the techies out there who like nitty gritty details:

    My computer was freezing at a black screen whenever I rebooted with the SanDisk Cruzer (8MB) in the USB slot. I now know my BIOS was set to default boot from a flash drive. I suspect it was barfing everytime it hit the U3 LaunchPad autorun, which was not working properly (something about a drive letter assignment) I tried removing the U3 software to no avail. Their website says I needed to have U3 LaunchPad running in order to uninstall. Buh? I disabled all external drives and reassigned the drive to a new letter that could not possibly be in use, but no luck.

    I called SanDisk who provided a link to a U3 utility that deleted the software and reformatted the drive. After using the reformat utility, Readyboost would not work. The tech had me reformat the drive manually. Still no luck. He adviced I return the defective device.

    Moral of the story? U3 Launchpad and its associated virtual CD drive suck. Readyboost rocks. I’m currently reformatting to NTFS. Thanks to all of you for sharing your experience and saving me the nightmare of returning a perfectly good device to the (Dell online) store.

    I had formatted FAT32 (default)

  42. Laura

    Update on my previous post. Sorry for the long response earlier but hopefully it’s faster to read than it is to get stuck on the phone with tech support for an hour only to be told to return the device.

    I reformatted from FAT32 to NTFS. I again got the error about my device not meeting the min specs for ReadyBoost. (I know this was false according to the manufacturer and I had ReadyBoost running previously) I hit “retest” x 2 and no luck. I closed all running programs, waited and hit “retest” It worked.

    So…. If you KNOW that your device should run ReadyBoost and does not, try retesting when your computer is quiet (kill unneeded processes if necessary)

  43. RS

    My laptop is already maxed out with 4 gb ram installed. Can ReadyBoost still help?

  44. San

    No RS, it won’t help you at all.

  45. DOllar

    Thanks Brian

    I am using Kingston 4GB (Class 4) SDHC with my fujitsu S6510. Initially, Vista rejects using this SD for ready boost, but soon after I reformatted the card and set the drive to be compressed it then worked. I do believe other SDHC can adopt Brian’s procedure to pass ready boost test.

  46. Jenny

    Thanks for this tip. it works great. I am pulling my hair out try to speed up my pc and hope this will last a bit.

  47. Rick

    Hi Folks,

    Was having similar problems as the rest of you. Have a Sandisk Mini SSD (8GB) card that I had placed in the card reader of my HP HDX9010NR running Vista Ultimate.

    ReadyBoost worked great until I screwed something up (can’t remember what….reformatted to Fat32 maybe). The ReadyBoost tab woudln’t even show up when I clicked Properties.

    So, How’d I fix it? Took advice from above and did a Full Reformat using NTFS at 4,096 (without compressing it). Once done, I took the card out, waited a few minutes, reinserted the card and whoallah!!! The Autoplay menu came up allowing me to “Speed up my system”.

    At first the readyboost tab said it wouldn’t work so I hit Test Again (maybe even twice) and now it works like a charm.

    There ya go. Hope it helps. Glad I found this page. I never would’ve thought to reformat to NTFS to get it working.

    Thanks and good luck everyone!

  48. fug22

    i set up the readyboost and noting is happing its still slow

  49. Jman

    added 2 GB of ram with a flash drive but I had to delete mostly everything that was on it to get it to work. I don’t see a whole lot of difference between 6 and 8 GB

  50. johngazna

    Reformatting and compression worked. Yeah! I have a Kingston Data Traveler 4GB. Thanks.

  51. stikk

    Hitting “Test” over and over worked! Thanks Jesse. I also tried NTFS formatting just before trying hitting test over and over again too.

  52. jow

    Ready boost is for those without much ram 512 or less, no point other wise and if you have 512 ram, add more. That simple for the cost of a readyboost usb stick you can have more ram. If you don’t know how to add more ram, go to crucials website and use there system scanner. Even microsoft admitted that ready boost was at most useless.

  53. Ricardo

    Yes RS, readyboost will help even if you have 4G already. Don’t beleive me San? OK, go to Walmart and buy 4G of flash(MS recommends 1:1 ratio), Walmart will let you return it if it does not work. Enable Performance Monitor to monitor Readyboost and see for yourself. OK now appologise.

  54. Nick

    Why do people not understand that computer speed is not purely reliant on RAM. If your CPU cannot perform quick enough, it doesn’t matter how much RAM you force into your PC, it will still be slow.

  55. PJ

    Hi All,
    Yes ready boost can help even if you already have 4GB ram.
    What ready boost does is move the paging file to the flash drive instead of the HD. Reading flash is quicker than reading the HD especially if the HD is already busy perhaps opening large files or programs.
    When you already have 4GB of ram your computer just uses the paging file less, therefore it will use ready boost less.
    install a gadget to watch you ram usage and when you see it start hitting 100% is when you will notice ready boost hitting your flashdrive.
    The thing is you have to have some pretty memory intensive stuff going on for it to ever hit the paging file. I rarely see my ram usage go above 50%

  56. liveman

    hey thank you very much friend that’s cool

  57. maybe just another fool

    I find it very comical that everyone that comments says,” Ready Boost is no substitute for system RAM.”


    The only people it will NOT help are those with Solid State Drives.

    Ready Boost is a substitute for PAGING FILE!! It is faster then paging files!! That is the point of ReadyBoost technology! It has never given anyone a boost in relation to System Ram.

    I see some comment on it only works when you have under 512 and other say other things related to RAM.. remember.. paging file has to do with DISC DRIVES BEFORE being offloaded to RAM and Ready Boost speeds THAT application of data ONLY!

    and to PJ… Paging file is used completely different then RAM even though it does work the way you said as well when RAM gets used up. It is always being used in relation to loading programs and recalling parts of those programs. RAM is for much more then programs. RAM is Used for recalling things OUTSIDE of the HDD. Like playing internet games and surfing websites. Those things are NOT on your HDD therefore to recall them RAM is used. Those things on your harddrive are recalled first from PAGING then offloaded to RAM. Then if the RAM gets taken up it will go back to the paging file. Thats why those with alot of RAM can lower the size of their paging file. They can never get rid of it because it is always needed! It just doesnt have to be large is you have alot of SYSTEM RAM because it will never have to be used in the event that your RAM is all used up.

  58. Lance

    Hello Ya’all:

    I found the secret on the SanDisk Cruzer (I think – it works so far). Here’s my story: I bought the SanDisk Cruzer 4GB at Staples. I plugged it in, and was able to activate Readyboost, however the U3 software/partition was really annoying, so I got the uninstaller from their website (Hard to find in the FAQ section), and uninstalled the U3 stuff. Then Readyboost no longer worked. So I downloaded the U3 reinstaller, and reinstalled it – Readyboost still didn’t work. I then uninstalled it a second time, and it worked. I got the idea from someone here (Bob, I think – if so, thanks Bob), who mentioned about running chkdsk. Now, I haven’t figured out the solution on a PNY Attache – it worked on the first boot, but not after that (and no software was installed on the Attache).

  59. john

    i have tried many tips and tools to optimize vista but i found reginout best of them all.

  60. lektira

    ist say to me its not 2. 0 ..why ?

  61. Sam

    so how long does the process usually take?

  62. Sam

    How long is the process?

  63. Ken

    I have a 2 GB Centron Datastick Pro. When I tried to use it for Ready Boost, I got a message saying that it didn’t have the required performance characteristics. After reading all your comments, I discovered that it was formatted FAT. I reformatted to NTSF. Now the computer doesn’t even recognize it. I tried it on 3 different computers running Vista Home Basic, Vista Home Premium and XP. It does not show up as a drive in Windows Explorer on any of them. How can I get it working again. Is throwing it away my only option?

  64. jaKob

    It work for me. Thanks

  65. govardhan patel

    I have bought a pc with vista on it six months ago from Bestbuy.
    It has a single dvd/cd drive that does not allow copy a cd or a dvd on it.
    It is very slow and has one year’s warranty that I have paid for to Bestbuy. I talked to them about this proble, they said it will take more than two weeks. I cannot wait for that long since I use it on a daily basis. It has Verizon internet on it and is very slow to start as well as to go on internet, The google is not showing up on it that I used to check my email with by logging on it.
    I need some help for my pc from a GEEK or anyone that I can afford.
    Thank You
    Govardhan Patel

  66. nir

    what is the difference between virtual memory on hard drive or use that topic?

  67. mahesh

    how to remove pen drive when i am using it as ready boost to speed up my system ?

  68. Russ

    Hi, can someone help me? I plug in my flashdrive and there is no option to speed up my system. Only open folders to view files. Help!

  69. Adeoye

    Hello Peoples.

    You this Problem is easier resolved than one would think. Ready boost is an autobot it can only use what you allow it. Change the file permissions in properties to “Full Control” and you’d see ready boost come alive. No need to format or change the file system.





  71. Eryxx


    WTF, are you an idiot?

    Folks, do not listen to or do anything this cretin says, doing any of this can screw up your PC beyond belief. I would hope anyone with a modicum of common sense would realize this, but there may be other people out there as clueless as Muramasa, just not as malicious.

    Go in peace…

  72. Razvan

    Hello, can anyone tell me… how much ram does a 4G Flash Stick if all its memory whit ReadyBoost??

    Is there a Scale or somthing??

    I have 3 G Ram pc..

  73. Deepak

    Hello Guys,
    This post is for all those who have not tried ready boost. This thing works really good. I was fed up with my x100e ibm thinkpad as it was not performing as better as it could. Even after upgrading ram to 3 gigs things didnt change. Then i was going through google and came to know about this ready boost. At once i formatted my pen drive with exfat format (only available with windows 7). I am using hp pendrive 4 gb. If you use exfat format for 4 gb it dedicates 8gb.. Now my lappy is happy.

    Thanks to everybody who came with this kind of invention.

  74. Robert Miles

    Is ReadyBoost any good for increasing the maximum size files Vista programs can open?

    My desktop has 8 GB memory and the motherboard cannot handle any more.

    The main index file for Windows Live Mail is approaching 8 GB in size.

    Ever since its size was about 4 GB (half the size of installed memory), the database compression feature of Windows Live Mail has failed to work properly.

    I thought that turning off SuperFetch would help, but it didn’t. I suspect that Windows Live Mail requires all the files it is working on to fit into main memory at once

  75. tong


More Articles You Might Like

Enter Your Email Here to Get Access for Free:

Go check your email!