[GRLUG] Solid State Drives

[Collin Kidder]

Tim Schmidt wrote:
> Quite true.  There are always pages (in ram) of cruft that must be
> there, but will either never or nearly never be accessed.  Getting it
> out of ram and onto disk frees up those pages for use by more actively
> accessed information, or just more file caching.  Either way, having a
> swap file _always_ increases performance.  The question is by how
> much.
>
> A desktop with even a Gb or two of ram can benefit quite a bit from a
> swap partition (especially if you have long-running, infrequently
> accessed processes - like a couple firefox windows with a lot of tabs
> open).
>
> On the other hand, we have a machine here with 32Gb ram that doesn't
> benefit much from a swap partition.  It still has one, and uses it,
> but only for said crufty pages.  As I look at it right now, it's using
> 140kb of swap.  35 pages.  Seems tiny and insignificant compared to
> 32Gb...  until you need it.
>
> --tim
>   
There really is no danger in leaving cruft in RAM so long as there is 
still free RAM. It is only when the RAM has been nearly exhausted that 
things need to be removed. It's a balancing act because it takes a long 
time to save things to swap and a long time to get them back (compared 
to RAM speed.) A tiny bit of swap usage (say, upwards of 10-15% of your 
RAM size or 250MB whichever is smaller) can help things out. Past that 
it's an albatross around your neck and you just need more RAM.