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讓我有更多的瞭解
筆者就來說說ReadyBoost功能的葫蘆里到底在賣什麼藥：
現在硬盤的數據傳輸率、轉速、緩存容量和接口速度都有了極大的提高，硬盤的順序訪問速度可以達到80兆/秒以上，也就是說，填滿1GB內存大約需要約12.8秒；但是由於長期以來，硬盤的尋道時間一直沒有很好的提高，這導致硬盤的隨機訪問速度只能達到可憐的1兆/秒，也就是說，填滿1GB內存大約需要1024秒！
對於小內存的系統來說，由於經常需要把內存中的數據和頁面文件進行交換，所以硬盤的性能就是瓶頸。對於應用程序和系統來說，大多時候，順序訪問速度倒並不重要，而隨機訪問速度才是決定性因素，而硬盤正是在這點上吃虧。
而U盤就有它的優勢了，U盤的隨機訪問速度可以達到硬盤的10倍以上。而ReadyBoost功能正是利用了U盤的高速隨機訪問能力，讓U盤作為Windows Vista的SuperFetch緩存，從而讓512MB內存的Windows Vista也能獲得比較好的性能。
提示 SuperFetch是Windows Vista引入的一種新型內存管理機制，ReadyBoost把U盤虛擬成SuperFetch緩存，從而提高系統性能。
http://blogs.itecn.net/blogs/winvista/archive/2006/08/01/readyboost.aspx
原文如上 還有下
http://blogs.msdn.com/tomarcher/archive/2006/04/14/576548.aspx
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Q: Isn't this just putting the paging file onto a flash disk?
A: Not really - the file is still backed on disk. This is a cache - if the data is not found in the ReadyBoost cache, we fall back to the HDD.
Q: Aren't Hard Disks faster than flash? My HDD has 80MB/sec throughput.
A: Hard drives are great for large sequential I/O. For those situations, ReadyBoost gets out of the way. We concentrate on improving the performance of small, random I/Os, like paging to and from disk.
Q: Won't this wear out the drive?
A: Nope. We're aware of the lifecycle issues with flash drives and are smart about how and when we do our writes to the device. Our research shows that we will get at least 10+ years out of flash devices that we support.
Q: Can use use multiple devices for EMDs?
A: Nope. We've limited Vista to one ReadyBoost per machine
Q: Do you support SD/CF/memory stick/MMC/etc.?
A: Mostly. In beta2, we added support for a small number of SD/CF cards on internal USB2 & PCIe busses. RC1 has a much broader support range.
Q: Why don't you support SD on my USB2.0 external card reader?
A: We unfortunately don't support external card readers - there were some technical hurdles that we didn't have time to address. In general, if a card reader shows a drive without media in it (like a floppy drive or CD ROM does), we can't use it for ReadyBoost.
Q: Will it support all USB drives, regardless of how they are ID'd to the OS ("hard disk drive" or "Device with Removable Storage")?
A: We have no way to tell what is on the other end of a USB cable so we do some basic size checks (since no one has a 200GB flash device ;-) ) and then perform our speed tests. HDD will not, however, pass our speed tests, and there is no benefit to using a USB HDD for ReadyBoost.
Q: Can you use an mp3 player to speed up your system?
A: Not currently. MP3 players use the 'plays for sure' interfaces to expose themselves to Windows. We require that the device appear as a disk volume. These aren't currently compatible.
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tonnyli wrote:
NAND flash...(恕刪)
感覺這位大大說的是對的
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.
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