What is SuperFetch ?
SuperFetch is one of the reason that makes you feel Windows 7 runs faster and smoother then any of it’s predecessor, although it has been out since Windows Vista Microsoft has yet made more performance tune with this service. SuperFetch is basically a service that runs actively in the background to cache up the most frequent used application into the memory. What is going to be cached are the programs and data files you as a user will most frequently use based on your prior usage. It will observe your PC usage pattern and from that predict what you will most likely to use. It’s also one of the reason why you see Windows Vista uses much more memory than Windows XP, since the concept is to retrieve data from the faster RAM rather than the HDD, slowest I/O device. This is also the reason behind why sometimes you can hear your hard drive glitching but you are doing nothing. This is because SuperFetch is caching the data, though it is always run in the minimal priority.
What Would Happen If I Disable it ?
So by disabling the SuperFetch will defiantly increase the available memory (more free memory as in memory holding no data what so ever), but by doing so you will get horrible performance. Not only the boot time of your system will be longer, application launch time will be longer as well. In the end, you might thought you are getting additional free memory from this trick but you will not be benefiting from any of this. It doesn’t matter if you have large memory or small memory, leave it on and let the Windows manage memory and I/O usage is the best way to increase the performance and stay fast.
In the end don’t get trick that you see more memory are free from the task manager, the free memory is doing nothing whereas before the free memory will cache your application and data file for faster process to the CPU. The disk is the bottleneck for all system, and SuperFetch is designed to minimize the bottleneck for the overall performance.