Re: [gentoo-user] Howzat!

[Joost Roeleveld <joost@antarean.org>]

On Wednesday 20 April 2011 15:16:40 Alan McKinnon wrote:
> Apparently, though unproven, at 14:37 on Wednesday 20 April 2011, Joost
> 
> Roeleveld did opine thusly:
> > On Wednesday 20 April 2011 11:25:27 Joost Roeleveld wrote:
> > > On Wednesday 20 April 2011 03:42:13 Dale wrote:
> > > > Joost Roeleveld wrote:
> > > > > On Tuesday 19 April 2011 17:54:02 Dale wrote:
> > > > >> Kfir Lavi wrote:
> > > > >>> I do a lot of compiling on my laptop using Catalyst for
> > > > >>> embedded.
> > > > >>> I upgraded my RAM to 8GB (2x4GB = 90$ ebay).
> > > > >>> I mount /var/tmp as tmpfs.
> > > > >>> Thats how I keep my SSD ;)
> > > > >>> 
> > > > >>> Kfir
> > > > >>> 
> > > > >>>      --
> > > > >>>      Poison [BLX]
> > > > >>>      Joshua M. Murphy
> > > > >> 
> > > > >> I got 16Gbs in my rig and I mounted portages work
> > > > >> directory on
> > > > >> tmpfs,
> > > > >> it
> > > > >> was actually slower.  That is likely a good idea to keep
> > > > >> from
> > > > >> wearing
> > > > >> out the SSD but it doesn't seem to make anything compile
> > > > >> faster.
> > > > > 
> > > > > Strange, it actually got faster on mine when doing that.
> > > > > Did you mount with "noatime"? :)
> > > > > 
> > > > > --
> > > > > Joost
> > > > 
> > > > Yep.  It actually took a few seconds longer compiling in memory.
> > > >  I
> > > > thought that was weird to tho.  It doesn't make much sense to
> > > > me.
> > > > 
> > > > Dale
> > > > 
> > > > :-)  :-)
> > > 
> > > Hmm...
> > > Will be doing some timing-tests then....
> > > Openoffice is a good one for that ;)
> > 
> > Ok, just done the tests. using tmpfs for /var/tmp/portage is quicker,
> > but
> > not by much.
> > 
> > Without TMPFS:
> > # time emerge -v openoffice
> > real 32m44.742s
> > user 20m18.320s
> > sys 5m38.000s
> > 
> > With TMPFS:
> > # mount -onoatime,size=7G -ttmpfs none /var/tmp/portage
> > # time emerge -v openoffice
> > real 31m30.835s
> > user 20m3.510s
> > sys 5m38.030s
> > 
> > Specification of this machine:
> > 12GB RAM
> > Quad Core Xeon W3565 @ 3.2Ghz with HT enabled
> > 
> > There are 2 drives in stripe-mode (software RAID-0) which does speed up
> > the I/O a lot.
> 
> I'd say the entirety of /var/tmp/portage for your OOo build fits into your
> ram disk cache so very little actual disk IO is happening.
> 
> I also noticed before switching to libreoffice-bin that the ooo build was
> largely cpu-bound anyway (disk light flashed seldom)

Alan,

I would love to do a better test then this.
Reason I took Openoffice is because it's known to be a large build (requires a 
lot of diskspace) and takes a long time.

If you know which other ebuilds might make for a better test, I will be happy 
to redo the test with those.

--
Joost