Sunday, February 4, 2007


I don’t really follow the Windows world, but I happened to read Peter Lewis’s article in the print edition of Fortune, where he mentions a new feature of Windows Vista called ReadyBoost. If your PC doesn’t have very much RAM, plug in a USB flash drive, and your PC gets faster. That sounded odd, since flash memory—whether in an iPod, a camera, or a USB key—has always seemed slow to me. After reading more about ReadyBoost, it turns out that flash memory is slow at sustained transfers, but that its access time is about ten times that of a hard disk. After all, there’s no platter to rotate and no head to be out of position. Even an iPod shuffle is faster than a hard disk for random 4K reads.

Vista uses the flash memory as a cache for parts of the virtual memory swap file, and this is apparently a big win for small page-ins. It routes bulk page-ins to the hard disk, even if the pages are on the flash, because with large transfers the disk will be faster. Flash drives wear out after a comparatively small number of writes, so apparently there’s also some kind of lazy writeback from the hard disk to the flash, reducing the number of writes so that the flash’s life will be extended to 10 years. All in all, I think this is pretty clever. The funny part is that Windows uses different drivers to connect to Plays For Sure devices, so they can’t be used with ReadyBoost. If you want to use your MP3 player to speed up your PC, get an iPod.

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What happens if the drive is pulled out?

Vista-ready PCs have special USB ports with a physical lock that prevents you from pulling out a drive that's being used with ReadyBoost.

Of course, like the rest of Windows, it works really well and will NEVER prevent you from removing a non-ReadyBoost USB device when you urgently need to.

It is not limited to ReadyBoost, obviously. The lock will engage when data is being written to the device and when Windows is making an automatic, every-hour, non-cancellable back-up of your flash drive, for your own saftey.

Scott: apparently it's no big deal since the flash drive is just a cache of what's already on the hard disk.

Shouldn't Microsoft concentrate on making sure the apps use less memory than thinking about these kind of work arounds?

According to a fellow blogger:

Ready boost shaved ~15 secs of my ~55 sec boot though it would likely be faster with a better pen drive;

Why do you need to swap when you are booting up? Isn't it weird when an operating system consumes all available memory just to bootup the sytem ? :D

Bruno: I don't know; maybe it's using the memory to cache disk reads? Sure, Microsoft should write apps that use less memory, and this is in some ways an ugly work around (because you've got this thing connected via USB). But they were supposed to ship a couple years ago, so I assume they were busy just getting the apps working. ReadyBoost seems like an effective way to add more developers working on performance without running into Brooks Law. Plus, if you only have 512 MB of real RAM, you'll want all the extra memory you can get, even if it's flash. With the price of flash dropping so quickly relative to regular RAM prices, I can see future PCs (or Macs) that ship with some flash built-in, as a standard part of the cache hierarchy.

Bruno, perhaps he is confusing ReadyDrive or SuperFetch with ReadyBoost? Also note that ReadyBoost uses FAT32.

Also, remember that everything on the flash drive is duplicated on disk. Which means that you can pull the drive at any time. This also seems to imply that writes will be slower (due to two locations to write to) and paging in will be faster since it can choose the fastest media to page in from.

I'm not sure if this was fixed in the final version, but according to external flash card readers are not supported (does not apply to jump/thumb drives). Hmm, even that FAQ seems to imply it speeds up reads only.

"Q: How much of a speed increase are we talking about?
A: Well, that depends. On average, a RANDOM 4K read from flash is about 10x faster than from HDD. Now, how does that translate to end-user perf? Under memory pressure and heavy disk activity, the system is much more responsive; on a 4GB machine with few applications running, the ReadyBoost effect is much less noticable."

Oddly, this isn't a completely new idea. Old PowerBooks (say the 5300c) have a maximum memory capacity of about 64MB, which can be a bit low if you're trying to run browsers. They do, however, have PC Card slots, into which you can put CF cards (with an adaptor). Tell the Mac OS to put virtual memory on the card, and you've got around the physical RAM restrictrion. All perfectly possible with System 7, although it does take manual configuration.

According to AnandTech, ReadyBoost is much less effective than having more RAM. One of their graphs shows that 1GB of RAM + 4GB flash is about half as fast as simply having 2GB of RAM. Compare the price of 1GB of RAM to a 4GB flash drive.

Of course, this is a cheap way to add a tiny bit of performance to beige boxes that don't have any additional RAM slots and don't come with enough to run Vista well.

Nice to see Microsoft innovate so well. Silly old Apple is doing worthless stuff like "resolution independent UI" and Core Animation in 10.5. Silly Apple and their Fisher-Price toy computers! You should have to know how to reset hardware IRQ addresses in order to send email or surf the web on a *real* computer.

Roy: I think that's it, except that it sounds like it's more than a tiny improvement if you don't start with much RAM. Most people probably can't or don't know how to upgrade their RAM. But anyone can plug in a USB stick.

Roy, but what happens when you have 2gigs of ram (the max in many macs) and you're still paging out and in like crazy?

Rosyna, then you're just going to remain bitter about installing Vista on that puppy until you get yourself a new machine. The memory stick is not a magic trick that will boost your machine to a higher class.

this is like bolting a lawnmower engine to a locomotive that has to pull 3-4 locomotives' worth of train.

it'll help, but not so much.

Can i use my 80gb ipod, and if so how much will it increase by?

Vincent: No, because the 80 GB iPod uses a hard disk rather than flash RAM.

ooo i see, thankyou

lovenish garg

Hello everybody, actually me problem is that I have only 256 MB of RAM but I still want to install window vista in my system. So if I use the Pen drive of 1GB in size will permit me to install window vista by using that pen drive as a physical RAM...l

how i can do such thing (i mean like ready boost)in windows xp home edition is there any software, thanks.

It is only available on Vista jamal.. Lovenish garg. I wouldnt put vista in a system with only 256 mb of ram...LOL.. trust me.. thats not enough! I run 4 gigs of ram and a 4 gb high speed kingston usb drive.. makes a noticable difference even with 4 GB of ram


is there any way i can get ready boost on an external hard drive? I'm using a 1 gig flash drive and i don't think I'm getting the max amount of RAM possible... its only putting out 920 MB


my external hard drive is 500 gigs by the way


readyboost will only work with a stick of max 4GB
- Must be FAT32
- Must be formatted
- Must have a speed of at least 2.5MB/sec

Is there a way to know that ReadyBoost is actually active? A gauge like the CPU meter?

I think its a cool feature. I don't use my SD slot that often, so I just plug in my 2G SD card and enable readyboost. If it shaves 1 or 2 seconds here or there thats great. I don't notice an incredible increase in performance...but you can't get that unless you upgrade to a new computer anyway. Seems like a neat way to use a slot and a card that would otherwise go un-used (excepted for the rare instance when I need to transfer a file to my camera or something...)

I just purchased a Dell Inspiron 1420 (because it was on sale) and I am VERY disappointed with how much Vista slows it down. I called Dell to return it, and they said I should try ready boost first. From what I've read... it's not going to help much. I've had the computer for 2 there is really nothing on it yet except Vista. Is ready boost going to make any difference in performance?

Jamal yes there is a softwar called eboostr that will allow you to install Ready Boost on a xp machine.When you lauch ready boost it puts a cache file on the memory stick which shows that ready boost is active.I have i gig ram and 4 gig of Ready Boost noticibly increases performance, especially with opening and running applications.

My laptop runs much smoother

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