Clearing cache?

I've been using the System Monitor to show the amount of work my proc is doing while folding.

When I first log in the memory indicator will say

"Memory: 11% in use by programs, 12% in use as cache"

after about an hour or so of up time, especially if I browes the web, or update and install something it will say:

Memory: 16% in use by programs, 72% in use as cache"

doesn't seem to matter what I do, I can not clear the cache. I've been told that I can run this command to clear it, but it doesn't work.


you can change the number after 'echo' to 1, 2 or 3, but none of them do anything that I can see. It still tells me that 70+% of my ram is being used as cache.

Anyone experienced what I am talking about?

For what purpose do you want to clear the cache?
The system is simply storing information that you use often within the cache

I don't think you can. I think you can disable it, might take a kernel compile though. There is no reason to clear it... cached memory is immediately freed for other uses if needed. You have 2 choices... use it as a cache, or let it sit idle. There is no performance boost to be gained by clearing it.

Take a look at how Linux uses memory. The output can be misleading if you don't really understand what it is doing. People often worry about all the memory being used, as in Windows that would be a bad thing. In Linux, this is normal and in no way a negative (unless your programs are using it all).