How-To Geek

Is Windows ReadyBoost Worth Using?


Connect a USB stick to a Windows computer – even on Windows 8 – and Windows will ask if you want to speed up your system using ReadyBoost. But what exactly is ReadyBoost, and will it actually speed up your computer?

ReadyBoost was introduced in Windows Vista, where it was a heavily promoted feature. Unfortunately, ReadyBoost isn’t a silver bullet that will make your computer faster, although it may be useful in some limited circumstances.

How ReadyBoost Works

ReadyBoost works in conjunction with SuperFetch. SuperFetch, also introduced in Windows Vista, monitors the programs you use on your computer and automatically loads their application files and libraries into your computer’s memory (RAM) ahead of time. When you launch the application, it will start faster — your computer reads its files from memory, which is faster, instead of from disk, which is slower. Empty RAM doesn’t do any good, so using it as a cache for frequently accessed applications can increase your computer’s responsiveness.

SuperFetch normally uses your computer’s memory – it caches these files in your RAM. However, SuperFetch can also work with a USB stick – that’s ReadyBoost in action. When you connect a USB drive to your computer and enable ReadyBoost, Windows will store SuperFetch data on your USB drive, freeing up system memory. It’s faster to read various small files from your USB stick than it is to read them from your hard drive, so this can theoretically improve your system’s performance.


Why ReadyBoost Probably Isn’t Useful For You

So far, so good – but there’s a catch: USB storage is slower than RAM. It’s better to store SuperFetch data in your computer’s RAM than on a USB stick. Therefore, ReadyBoost only helps if your computer doesn’t have enough RAM. If you have more than enough RAM, ReadyBoost won’t really help.

ReadyBoost is ideal for computers with a small amount of RAM. When Windows Vista was released, Anandtech benchmarked ReadyBoost, and the results of their benchmark were informative. In combination with 512 MB of RAM (a very small amount of RAM – new computers today generally contain several gigabytes), ReadyBoost offered some improved performance. However, adding additional RAM always improved performance much more than using ReadyBoost.

if your computer is stressed for RAM, you’re better off adding more RAM instead of using ReadyBoost.


Image Credit: Glenn Batuyong on Shutterstock

When ReadyBoost Is Worth Using

With that said, ReadyBoost may still be useful if your current computer has a small amount of RAM (512 MB, or perhaps even 1 GB) and you don’t want to add additional RAM for some reason – perhaps you just have a spare USB stick lying around.

If you opt to use ReadyBoost, bear in mind that the speed of your USB drive also determines how much improved performance you’ll get. If you have an old, slow USB stick, you may not see a noticeable increase in performance, even with a small amount of RAM. Windows won’t allow ReadyBoost to be used on particularly slow USB flash drives, but some drives are faster than others.


Image Credit: Windell Oskay on Flickr

In summary, ReadyBoost probably won’t improve your computer’s performance much. If you have a very small amount of RAM (512 MB or so) and a very fast USB drive, you may see some increase in performance – but it isn’t even guaranteed in this situation.

Chris Hoffman is a technology writer and all-around computer geek. He's as at home using the Linux terminal as he is digging into the Windows registry. Connect with him on Google+.

  • Published 09/7/12

Comments (34)

  1. fred huber

    Also note if you boot from SSD-drive Ready-Boost will be disabled for all devices.

  2. Flank

    not convenience

  3. Frank

    I have a netbook on Windows 7 with the maximum RAM that will fit – 2GB.

    It has an SD card slot where I keep 4GB of class 6 SD card [slower (class 4) gave me a message not fast enough or something] dedicated to ReadyBoost – I haven’t measured for sure but my feeling is it’s a little faster in general.

  4. Anybodysguess

    I use it when running real time simulation games, like Phun.

  5. Bigtech

    That said considering the people most likely to require ReadyBoost are Netbook, Tablet and Laptop users that are unable to upgrade their RAM. Us desktop users… not so much. And yes Running a SSD as your primary drive more or less negates the need for Readyboost.

  6. john3347

    Early on, while Vista was still very young, I plugged a “dime store” grade USB stick in my computer and enabled ReadyBoost. Not only did I not detect any speed improvement, but only after a few days the USB stick was down to nothing. I assumed that there was such frequent writing and re-writing that the USB stick only lasted 3 or 4 days. I decided that ReadyBoost was not only worthless, but very destructive to at least cheap USB drives.

  7. Dwight Hoyes

    Agree with the article and also I experienced a couple booting issues that I eventually traced to ReadyBoost. My advice is stay away from it.

  8. DaveP

    For older laptops with RAM limits like 1 or 2G it’s great.
    I have a desktop with a 4G limit. plug in an 8G USB and it helps.
    NOTE: SanDisk has some very tiny, very fast USB drives that work great. Cruzer Fit USB Flash Drive. Small enough you forget they are plugged in.

  9. skritko

    Laprop-Win 7 32 bit pro 3 gb ram 5400revs hdd + redyboost works like magic. Without it its just a regular PC. So I am sorry, I am keeping it.:-) Oh yes an running virtual PCis like night and day in comparison.

  10. KMFDMKid2000

    I’ve got 16GB’s of DDR3 on the desktop, but I still throw in another 16GB’s of ReadyBoost on it. It’s a gaming PC that also doubles as my networking lab when I’m trying things out to practice for I.T. certification exams. So the way I see it, day to day ReadyBoost won’t help much, but when I’ve got 5 virtual servers running, or if I’m cranking some graphics heavy game, why not employ a $10 USB drive that I’ve got just sitting there doing nothing anyway?

    The way I see it, every little bit helps, especially when you’ve got some high demand computing to do.

  11. chuckiewithanf

    LOL @ both example photos are Apple machines (yes, I know you can run Windows on an Intel Mac, f-off). Also, readyboost is too little, too late. An SSD negates the need for it entirely.

  12. r

    I have mountains of ram, cache mem & HD space
    –my disk read performance is quite fine without any kind of “boost”

  13. CyberCowboy

    Is Ready Boost/Ram still limited to the 4 (3.25) GB upper limit in a 32-bit configuration? I.e. if I have 4 GB physical ram and throw a 8 GB USB device for Ready Boost is the 8 GB wasted due to the physical ram or will I still get some sort of a performance boost?

    Also would multiple, smaller USB drives all running RB preform better since they’d have more buses going to them than a single larger device?

  14. lesle

    The Corsair Accelerator reportedly does the job.

  15. grahm

    What about using usb 3.0 thumb drives?

  16. Ting Tong

    I love it…. now my laptop levitates 4 inches above my table top, no need for the USB chill fan!

  17. Davey126

    I found a small ReadyBoost cache can help performance when bringing a system out of hibernation even on systems with ample memory. You may have experienced sluggish response and a solid drive light as SuperFetch and other processes try to reinitialize all at once for the first minute or two when resuming from hibernate. With ReadBoost enabled both my laptop and desktop are much more responsive during this period. The drive light is still solid but the system is much more responsive. Running Windows Peformance Monitor shows a fair number of hits from the ReadyBoost cache. This even works if the ReadyBoost cache is purged by Windows when entering/exiting sleep or hibernation (try enabling write caching on the device to prevent purges). Obviously this trick only works when the system drive is not a SSD (nor is is needed for SSDs due to quick access times). You only need small ReadyBoost cache on a fast flash drive or SD card – 256-512K is sufficient. Give it a whirl and post your findings.

  18. Paul

    Use eBoostr instead (google it), which uses real RAM and is therefore truly faster.

  19. DrChiron

    First I am assuming there is no provision for the ReadyBoost system to cache Windows own files that are loaded during initial bootup. If that is NOT true, then it helps there.

    On a system with no SSD, won’t the initial loading of the frequently used programs already cached in a ReadyBoost drive (such as Windows Explorer, a browser, Office apps even Notepad) show faster program starting, or does ReadyBoost not check for program availability in the cache after a reboot?

    Could the hiberfil.sys not be located in a ReadyBoost cache instead of the root of the SYSTEM drive?
    As mentioned in a previous post, excepting SSD equipped systems, this would seem a logical speedup.

  20. AnthonyL

    I use ReadyBoost for last year on my Toshiba laptop which has 2 GB RAM Running Windows 7 . Instead of a USB drive, I use an 8GB SDMicro RAM. This way I don’t have to worry of plugging and unplugging the USB drive when I’m done.
    I find the performance of my laptop much better. Especially when I running Visual Studio 2010 and VMware.

  21. Steve Rose

    I have a Dell E6410 w/ 4GB RAM and Win7 Pro 32bit. I use a fast 4GB SanDisk SD card permanently left in the SD slot and I have tried some programs w/ and w/o the ReadyBoost and the machine is definitely faster with the ReadyBoost. I am thinking of upgrading to a SSD drive (currently have a Seagate Momentus XT hybrid drive) and if I do, I will definitely not need ReadyBoost, as said above.

  22. DiggerP

    I wonder if people are really doing their “homework” .
    Most modern HDDs have much faster Read and Write speeds than most USB flashdrives ,
    except maybe for the top models which are more expensive than RAM.
    This was true in “Vista time” and still is today.
    Looks like a placebo effect. Tell people it’s the real thing and they believe it.
    For me ReadyBoost is a fallacy foisted on us by Microsoft ,because of Vista being a hog and used on underpowered machines.

  23. Josh

    So, this is kind of like Swap on Linux, eh?
    To be honest, I’d never use R.B. It reads/writes so many times onto a USB stick, it would quickly kill it off (and even faster for an SD card).

  24. Davey126

    The hiberfil.sys file must be located in the root of the same partition that contains Windows files.

    The performance improvement I outlined in a previous response comes from having multiple sources (channels if you wish) to pull information Windows is looking for during the first 30-120 seconds after recovery from hibernation. Even a fast hard drive can not provide the data fast enough (tons of random reads, many of them from SuperFetch trying to repopulate the cache) so the system bogs down. ReadyBoost helps in this scenario because some files, both windows and application can be read from the normally slower USB drive. After disk activity settles down ReadyBoost offers no advantage on a system that has adequate memory. Of course, doubters will quickly post a negative response and move on. Best way is to try it and see for yourself. Might help, might not. In my case the benefit is both measurable and significant on modern, well equipped machines that lack a SSD.

    Someone asked if ReadyBoost can cache Windows system files. It can, but these files are normally flushed when using hibernation. There are ways to prevent this as noted in my original post. But even if the files are flushed ReadyBoost can help as a few key DLLs are copied to the flash drive shortly after recovery from hibernation and read over and over again as the hard drive is swamped handling other requests. This can be easily observed with disk monitoring tools.

  25. pbconnect

    I have an older Dell Dimension 4600 with 1 gb of ram and I use a Sandisk 1gb flash drive for readyboost in Windows 7. I do notice some improvement in surfing the web and using office but not that much. I don’t play games or use many intensive applications so I couldn’t tell you if it helps in that area. I plan on installing 4gb of ram soon though and I doubt I’ll have a need for the 1gb of readyboost anymore. Still it may be “nice” just to know that its in there.

  26. Spock

    Dr. Chiron, that is illogical.

  27. J. Anthony Carter

    Early in ’07 I bought this laptop, an HP Pavilion 6400 w/ 140G HDD, and 2G RAM. After a while I was getting messages from my system about memory issues and suffering the consequences too. One of the things my PC guy told me to think about was ready-boost. I knew what it was having run across it in my normal farting around. SSD’s weren’t readily available yet (or hella expensive), so since I’d already bought a 4G USB and wasn’t really using much of it yet, I plugged it in and assigned it’s space to ready-boost.
    I still haven’t gone to buy an SSD or 2) two G RAM cards because my PC seems to be finding the USB stick a handy place to do business. I haven’t had any more memory issues and while it may not be as fast as additional RAM, I’m not having to go out and buy an SSD because the USB’s little orange light (showing it’s being utilized as additional RAM) keeps flickering merrily along!

  28. Thomas

    @grahm – I thought about that too. I would think a USB 3.0 port with a modern USB 3.0 memory stick should be very helpful. You would easily be able to access it much faster than an old 5,400 RPM disk. Here comes the problem though. I am not able to upgrade the memory in my laptop because it is already maxed out at a ridiculously low 2Gb and I would have to replace the motherboard to replace the USB ports. Too expensive. I would be much better off switching to a good SSD; at least until the company’s lease expires and we get to trade in these laptops for newer models. If you have a desktop where you can add a USB 3.0 card, then you are already in much better shape than I am. Let us know how it works for you.

  29. Dave

    Question on this. I have a Windows 7 Pro laptop with 4gb of RAM in and it runs fine normally. Does ReadyBoost provide help in situations where you are running very intensive applications such as VMPlayer? When I currently run some of my VM’s, I’m at 90-95% RAM useage. Will ReadyBoost provide any benefit in this case?

  30. Mergatroid

    I have a spare computer containing a Core 2 Duo with 2G of RAM. I added a fast USB stick for readyboost, and I noticed in the original Guild Wars that once you had been to a town, going back to that same town did not produce any hard drive activity and no delay. So, I have left it in for a couple of years now and it’s still working great. I’m not purchasing more memory for this computer since it’s a spare (I let guests use it), so I see no need to purchase more memory when the $18 4Gb USB Flash drive I installed seems to be working well.

  31. Luis C Mesquita

    My own experience using ReadyBoost has been highly positive. For ReadyBoost I used a dedicated SanDisk 16GB Cruzer Switch (Formatted with ExFAT) and am pleased to note the computer performance has improved markedly. Typically I have one or more instances of the following apps open at a time: Microsoft Visual Studio 2012, Word, Excel, IE9, Chrome, Acrobat Reader, Oracle , NetBeans etc. Using ReadyBoost has made the computer far more responsive. I like the following relative to ReadyBoost
    1. ReadyBoost ease of use
    2. 16GB USB Flash drives are rather cheap and do not require us to open the comp.
    3. The system has become responsive inspite of having all the apps above.
    4. the hard disk no longer groans and growls when multiple apps are open. I assume a quiter Hard Disk will live longer.

    Hope that Microsoft keeps developing this feature further specially considering that USB3 will increase the speed not only for random reads but for sequential reads as well.
    Another consideration is hard disk performance in the presence of motion. In mobile computers, when acceleration is detected, a hard disk head is brought to a stop to prevent a disk crash, thus effectively bringing the data transmission rate to zero. In this scenario, ReadyBoost could continue supplying data from the Flash drive as it is not adversely affected by motion.

  32. Luis C Mesquita

    I have tried the ReadyBoost feature on a Laptop running 64 bit Win 7, and having 4 GB of RAM. There is a marked improvement in the system performance with ReadyBoost using a dedicated 16GB SanDisk Cruzer, USB 2 drive. Application loading and switching has become must faster.
    Secondly, the 320GB hard disk no longer growls and groans when several memory hogging applications are open. I presume, that a hard disk that is quiter due to ReadyBoost will last longer. ReadyBoost, therefore has the potential of reducing hard disk failures and all the hassles of trying to recover lost data. It is far cheaper to replace a USB flash drive used for ReadyBoost, than it is to replace a failed hard disk that stores the OS files and crucial user data.

  33. Gadget Freek

    Why are the hardware photos of Apple computers???
    Didn’t find any windows computer photo you could use?
    That’s just sloppy…

    Anyway, there are a lot of computers, mainly laptops, ehre you can only put 2GB. You just say it can be usefull to 512MB ram computers, but nowadays the usb pens are so cheap that if you can add 8GB more “RAM” to a netbook for as little as 5 or 6 pounds it would be worth it.

  34. Bruce (

    I did some experimenting with ReadyBoost some time ago. I tried it on my 2gb pentium laptop, a couple of 4 gb dual-core Pentiums, an 8 gb I5, and a few others. In general, launching and switching multiple apps was just a lot smoother. It reminded me of when I switched from a single cpus to multiple cpus – for most things the system didn’t seem faster, but doing multiple things just worked better (windows snap up and down quickly, menus responded noticeably quicker, etc.).

    Just to try and measure things, I stumbled upon using Defraggler. It has a benchmark function that uses random disk reads. On all these systems I ran the benchmark, set up an 8gb Patriot Supersonic Xpress for ready boost, and then ran the benchmark again. The old pentium 2gb laptop sped up by 31-64%, a netbook (2gb dual atom) 37-200%, Dual Core Quad 3gb 140%, Dual Core/hyperthreaded I5 8gb, 75-130%. Speedup got better the more often I ran the test.

    While random disk reads might not be the greatest metric, it helped to put a rough number on what I observed directly. Readyboost is clearly an improvement (at least in data access behind everything). I find I pop my usb drive into whatever PC I’m using and it is just more responsive to use than without.

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