Why does using Fsutil make your windows computer run faster?

Question

I have stumbled across this video which supposedly makes your computer run faster:

Fsutil behaviour set memoryusage 2

However, I don't understand why it makes your computer faster. This seems too good to be true, can something really speed up your computer? Does it have any drawbacks or causes any hidden problems for your computer?

Answer 1

This is entirely dependent on how you usually use your computer, and its specifications. From Windows docs:

Configures the internal cache levels of NTFS paged-pool memory and NTFS nonpaged-pool memory. Set to 1 or 2. When set to 1 (the default), NTFS uses the default amount of paged-pool memory. When set to 2, NTFS increases the size of its lookaside lists and memory thresholds. (A lookaside list is a pool of fixed-size memory buffers that the kernel and device drivers create as private memory caches for file system operations, such as reading a file.)

so basically it increases the amount of paging your file system can use out of the total shared pool. This of course, means less for other processes. The documentation is even explicit about it:

Increasing the physical memory doesn't always increase the amount of paged pool memory available to NTFS. Setting memoryusage to 2 raises the limit of paged pool memory. This might improve performance if your system is opening and closing many files in the same file set and is not already using large amounts of system memory for other apps or for cache memory. If your computer is already using large amounts of system memory for other apps or for cache memory, increasing the limit of NTFS paged and non-paged pool memory reduces the available pool memory for other processes. This might reduce overall system performance. This parameter updates the HKLM\SYSTEM\CurrentControlSet\Control\FileSystem\NtfsMemoryUsage registry key.

So basically if your ram usage is not to high, it might be worth it, especially when loading and re-loading resources from your hard-drive. Gaming is a notable area of benefit, where often the GPU is doing most of the work, leaving the RAM somewhat free, and the same stuff needs to be loaded constantly. Of course, there is also a GPU cache for that, so the benefit increase is not straightforward.

Bottom line - this gives the file system more page space out of a total shared pool of fixed size, so is not "free".