Loving Microsoft Technologies.

Recent Posts



Email Notifications

.NET Related

Other MVP

My Blogs in HK

.NET Insider


USB Flash Disk to be.....Ad-Hoc Memory in Windows Vista

Last Sat, Jack was wondering a special feature on Vista, it is "using your USB Flash drive" to be the ad-hoc extra memory for your computer. He mention that the "transfer rate" should be faster from Harddisk than from USB or from USB Flash Disk. And after searching, I found the MAIN is.....random read/write speed. For  the traditional harddisk, the disk still need the physical "header" to search, go to the sector and do the read/write. The worst case will be one sector in HD head and second sector in HD tail. And back to head again and back to tail again. So, the key for ad-hoc memory will be........same tech of REAL Memory, read/write random in fast speed. And the below was the one i found, i forward it to here as i like the pictures.

ReadyBoost - Using Your USB Key to Speed Up Windows Vista

One very cool feature of Windows Vista – especially for machines not natively equipped with the kind of horsepower to fully enjoy the rich visuals of Windows Presentation Foundation (Avalon) applications is ReadyBoost. ReadyBoost enables you to plug a USB key into your machine and have Windows Vista use it as memory. I hadn’t actually used this myself, but had heard of it long ago. When a reader emailed me asking if this was an urban legend, I decided to check it out for myself and was very impressed with how easy and seamless the process is.

Installing/Configuring the USB Key as Memory

First I took a standard USB 2.0 key (I’ll list the prerequisites shortly) and plugged it into my machine. I’m running Windows Vista Beta 2, Build 5346, but I’m told that this works with the latest CTP made available to beta and TAP members as well as MSDN Subscribers. Upon plugging the USB key into my computer, I was greeted with the standard "AutoPlay" dialog box asking how I wanted to the operating system to treat the USB key. However, with ReadyBoost I get the additional option (circled below in the screen capture) of using the key to "speed up my system".

AutoPlay dialog box displayed when a valid USB Key is inserted into a machine running Windows Vista

Once I click the "Speed up my system" option, the Properties dialog box for the device is displayed where I can specify to start/stop ReadyBoost usage of the device and how much space I want used as a memory cache. (Actually, according to one of the Product Specialists here, this space is used more as a flash-based page file than true RAM, but the impact is that the more space you choose here, the more benefit you’ll get in terms of overall system performance.)

The device Properties dialog box allows you to turn on/off ReadyBoost for that device and to set the exact size of the cache.

(In order to return to this dialog box, open the Computer window, right-click the drive (F: in this case) and select Properties. From there, click the Memory tab (as shown in the previous screen capture and adjust the settings as needed).

For the inquisitive, opening the drive in an Explorer window reveals that ReadyBoost has created a cache file of the specified size.

Example cache file created by ReadyBoost on a USB Key

Things to Know About ReadyBoost

If you have a USB key configured to use ReadyBoost and then insert a second key, Windows Vista will display the Properties dialog box where you’ll see the message on the Memory tab as shown in the following screen capture.

Example of a USB Key that cannot be used by ReadyBoost as it doesn’t have enough free space for a cache

While ReadyBoost will work with other devices – such as SD Card, CompactFlash, etc. – I’ve only used it with a USB key and here are the baseline requirements the team gave me regarding what ReadyBoost will work with:

  • The USB Key must be at least USB 2.0
  • The device must be able to do 3.5 MB/s for 4 KB random reads uniformly across the entire device and 2.5 MB/s for 512 KB random writes uniformly across the device.
  • The USB Key has to have at least 64mb of free space
Posted: Thu, May 11 2006 11:18 by kenlin | with 1 comment(s)
Filed under:


David said:

I haven't really been following what's been happening with Vista - other than the headlines I've been reading over at DIGG.  When I saw this headline, however, I had to come and take a look.
This sounds like a great feature.  The whole "no moving parts" aspect of the flash memory system almost guarantees faster access speeds.
You did a good job at explaining this feature - well done.

Now, I'm wondering if it'll be possible to use a USB flash drive as a scratch disc for Photoshop - it'd sure speed up some of those more elaborate filters.
# July 20, 2006 7:49 PM