Windows 7 - about readyboost.....

recently i found a number of old thumb drives from the bottom of the drawer.....i wonder if the speed of the system increases by plugging in more USB drives? Which one is more important?
i. the size of a thumb drive?
ii. the speed of a thumb drive?
iii. the number of drives used?

well the drives are not much useful anyway, and there are vacant USB port, just wonder if it helps the performance of the system.

.
As far as I know there is no benefit to multiple drives over a single drive. I believe speed is the primary consideration. If a drive is not fast enough Windows will say it is not supported. ReadyBoost barely makes a difference unless the system is ram-starved to begin with.

It depends on how much RAM you have in the system? If you have 2-3GB's with 32-bit 7, or 4GB's with 64-bit 7, then Ready Boost isn't going to increase performance one bit. You might however see a slight increase if you have less than 2GB's.

The important factor is the access time. You can test your sticks with HDTune (have it run to the end - else you will not see the access time). If the access time is in the 1 to 2ms range, you may get a slight performance improvement for a small RAM. But with any RAM size above 2GBs, you will not see any difference - in fact it may be counterproductive because of the unneccessary overhead.

As posted above, I've also found that readyboost doesn't make much difference on systems with adequate memory. On a 2006 Dell Inspiron e1505 with only 1 GB of RAM, 4GB of readyboost makes switching between applications noticeably faster, but I wouldn't have any way of quantifying that. Reducing the memory to 512 MB, the system becomes almost non-responsive without readyboost, so it can make a big difference on marginal systems. Adding a 2Gb flash drive to the 4Gb already being used for readyboost made no noticeable difference whatsoever, so I doubt there's any benefit to having more than one flash drive or SD card for readyboost.

In order to understand this phenomenon, you have to look at the functionality of Ready Boost (RB). What RB does is to move the page file to the stick and it pulls the pages as required form the stick. That's why the access speed is so important - data transfer rate is of a lesser importance because the amount of data for the pages is small.

It should also be understood, that RB writes the pages to the stick AS WELL AS to the disk. This is necessary because the stick is a removable device and the system must remain operational in case the stick is being pulled from the system (erroneously or not). This is why you have to account for a certain overhead with RB which is counterproductive for the cases where RB does not help.

As to the size of the stick, it is defined by the size of the page file which usually is no more than 1.5 times the size of RAM. Therefore RB with RAM sizes of 512MB or 1GB need not have a stick bigger than 2GB. For RAM sizes 2GB and up, RB makes little sense because page faults are rare. This can be easily verified in the Resource Monitor > Memory tab. Here you have a column called "Hard Faults". This shows the number of page faults that actually occur and if you verify that in a system with 2GB or more RAM, you will see all zeros or very low numbers. Thus a faster access to the page file on a stick will have no bearing on the overall performance - all you get is the extra overhead from the dual writes during page-out.

Interesting.. with 2gb of memory on the 32bit version, hard faults only occur with multiple applications starting up for the 1st time. Was not entire sure how readyboost worked... thks

oh.....then i have a completely wrong concept on the readyboost.....i thought it is putting frequently used files in the thumb and running as a raid. instead of getting 1MB from the disk, it is getting 500kB from each of the two sources at the same time. thus it speeds up. that's why i was thinking if i use more than one thumb may have a higher speed (i.e. e.g getting 100k from each of the 10 drives at the same time.)

I think you are right. You got the wrong idea. RB is solely designed to increase the speed of paging.