no swap makes system slower - why?
raphael.morcha at gmail.com
Sun Nov 4 15:01:56 UTC 2007
On Sun, Nov 04, 2007 at 08:08:23AM -0200, Felipe Figueiredo wrote:
> 1- Since swap access is slow (disk) compared to real RAM, I would expect that
> a swapless setup to be faster.
I can't say for the rest of the 2 questions below but for this questions I'll point out that swapless system means that there are no means to swap pages of memory in RAM everytime your system uses more RAM than is available.
Otoh, if there is swap, your pages in memory is fetched/restored using the swap space on_demandly manner.
Swapless system should in general be faster in terms of I/O but it depends _mostly_ on how much mem your applications are using. If they ask for a lot, they get a lot. But if they ask for a lot_lot, that requires lot_lot of memory as well. Right? And when the system doesn't have lot_lot of pages available, it swaps using (in your case) sda3.
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