Art Alexion on 17 Aug 2009 20:37:56 -0700


[Date Prev] [Date Next] [Thread Prev] [Thread Next] [Date Index] [Thread Index]

Re: [PLUG] Swap on SD


On Monday 17 August 2009 22:37:25 Walt Mankowski wrote:
>   On Mon, Aug 17, 2009 at 10:28:28PM -0400, Art Alexion wrote:
> > On Monday 17 August 2009 11:28:16 Austin Murphy wrote:
> > > I think you would be far better off to spend the money on a RAM
> > > upgrade and continue without swap.  The 2 GB RAM upgrade for the EEE
> > > PC 1000 is only $30.
> > > http://www.crucial.com/store/listparts.aspx?model=Eee PC 1000
> >
> > I have done no quantitative testing, but qualitatively, the system seems
> > a lot snappier since I tried this.  I had feared that the SD would be too
> > slow to help, but I guess it is faster than no swap at all.
>
> I assume by "this", you mean using the SD as swap, and have not (yet)
> bought extra RAM.

Yes


>
> > I am planning the upgrade to 2 gb, but plan to supplement it with the 4
> > gb SD as long as it seems to be helping.
> >
> > Maybe it's optimistic perception on my part, but that works, too.
>
> I vote for "optimistic perception", because I really can't see how it
> can possibly make it run faster.  It's always going to be orders of
> magnitude faster to use system memory than swap space.  When you use
> swap, you by definition are trading more virtual memory space for
> slower speed whenever memory needs to go back and forth to swap.
>
> Are you sure you're even using the swap space?  When you run top, does
> it say that any of it is in use?


You seem to be implying that adding swap where none existed at all somehow 
diverts the use of physical memory to swap.  I didn't remove the memory.  Is 
that what you mean?

So what happens to a Linux system without swap that runs out of physical 
memory?  how does it manage that extra memory demand?  My guess is, whatever 
it does is not as fast as if it could use swap.  If that wasn't the case, it 
would seem that no system would ever benefit from swap.

Last, top does report that I am using virtual memory.



___________________________________________________________________________
Philadelphia Linux Users Group         --        http://www.phillylinux.org
Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce
General Discussion  --   http://lists.phillylinux.org/mailman/listinfo/plug