Understanding PC: Will Increasing PC Speed By Increasing FileSystem Cache Pay Off?

I recently helped a friend clear up his PC problem when he reported lags and glitchy performance with his Windows XP. A brief questioning of the situation revealed that he had done a filesystem cache tweak which leads to his PC performance degrading.

There is a common belief that by increasing the FileSystem Cache of Windows, users can experience a boost in PC performance, since Windows will tend to use the maximum available RAM to power applications, resulting in more responsive scenarios. In fact, I am going to show you how to do it here:

1. Click Start, type in “cmd” and you will see the command prompt icon.
2. Right Click the cmd icon and choose “Run as Administrator“
3. Now in the command prompt windows type in the following command.

fsutil behavior set memoryusage 2

4. Now restart windows 7.

If you want to review your actions, using the following query in cmd will show you the value.

fsutil behavior query memoryusage

There are many websites that claim that any users can perform this command to increase PC performance. Do not believe this, for some of them did not properly explain the logic behind FileSystem Cache or conduct a benchmarking...which is misleading, i must say. If unsuspecting users do this on a PC without the proper requirements, it will not have any effects and if worse, will result in an even worse performance than before!

By nature, increasing FileSystem Cache size means that your PC will attempt to maximize RAM usage, usually with a benchmark for example, it will prevent RAM usage from falling below single digit level and make applications run at the maximum possible performance. Your PC can also handle more concurrent operations, since the page pool limits are being raised. This tweak is popular with servers, since they are the ones that have to handle multiple file operations.

With the logic above in mind, we can conclude that:

1. Increasing FileSystem Cache size is best performed on a PC with large amount of RAM onboard, with a mimimum of 2GB on Windows XP & Windows 7 and an additional 0.5 GB on Windows Vista. Most importantly, a majority of these RAM must be free from application use, otherwise applying the tweak will result in negative effect.

2. The success of FileSystem Cache tweak is heavily influenced by memory amount, therefore 64-bit OS can take advantage of this tweak rather than 32-bit OS. The reason is that the maximum RAM that can be used by 32-bit OS is 3.5 GB, while 64-bit OS can use 4GB-8GB and beyond.

3. Since this tweak is originally for servers that operates at something like 8GB & beyond, i highly doubt that a normal PC system below 8GB RAM could actually see a difference by applying the tweak.


I know i will need someone's in-depth research and benchmark to support my conclusions, so i dig around and found this excellent analysis by Eric aka TweakHound.

In his research, you will notice that the conclusions i've made regarding the FileSystem Cache tweaks are proven. With benchmarking, research & consultation from expert, Eric concluded at the end of the test, that on normal PC, the tweak is USELESS.

My final advice to majority of users out there is, don't waste your time applying this tweak. As I stated before, this tweak works best with 64-bit OS that runs on high amounts of RAM and also the hardware befitting those of server computers, but trust me, even if your computer fit these requirements, the performance improvement is not enough to produce a positive impact.