SLUG Mailing List Archives
Re: [SLUG] Advice Request for moving a Ubuntu installation to a larger disk and 4Gb RAM
- To: slug@xxxxxxxxxxx
- Subject: Re: [SLUG] Advice Request for moving a Ubuntu installation to a larger disk and 4Gb RAM
- From: Alan Tyree <alan@xxxxxxxxxxxxxx>
- Date: Wed, 28 Oct 2009 13:47:32 +1100
- Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:date:x-google-sender-auth:message-id:subject:from:to :content-type; bh=jxW0UgTr9SXw8VYHMt7TMs/TsoUct4IsA9k/4sC5gys=; b=Lh74LIJMeEzOhbTw1lel+DxrBLuIwo8wOeAodOfAH89lmjFXd4hf4+5ACLhVPtBDjz 11zjs4Q0yqMnXq+6RYHRvmaem4mt4uuqxg2CzZs4g2+NCBGqKRZhVPv/BWRsaHmdFAxR 0E+Hfs0P4aXikQ62z8jRkIukfrEfqoJioRftU=
- Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type; b=dA5hR9IE6Dct/pNT0MF/wVhTlweyrCGWg/fTM5YKKAgKrk6IykFJV0jTmO5jIldn+q IoZhcY1o3vKQp3j5T9YjTp259BQ4ej0Ii/2v7Z7pkqdnqEmaqsuW4qQon5RIjyForWbG GLnsH8/EmXG6R+i9CosWtzHE1FW/9R5qI5Xsk=
On Wed, Oct 28, 2009 at 12:51 PM, Daniel Pittman <daniel@xxxxxxxxxxxx>wrote:
> Alan L Tyree <alan@xxxxxxxxxxxxxx> writes:
> > On Wed, 28 Oct 2009 10:39:48 +1100
> > Robert Collins <robertc@xxxxxxxxxxxxxxxxx> wrote:
> >> On Tue, 2009-10-27 at 13:15 +1100, Bill Donoghoe wrote:
> >> >
> >> > 1. What do I need to do to get Ubuntu to use 4Gb RAM? My current
> >> > Jaunty installation only recognises around 3Gb. Is this just a kernel
> >> > upgrade or ....
> >> If I remember correctly we don't support > 3GB on 32-bit installs
> >> anymore - the performance overhead is terrible.
> > alant@stormy:~/data$ uname -a
> > Linux stormy 2.6.26-2-686-bigmem #1 SMP Sat Oct 17 18:25:48 UTC 2009
> > i686 GNU/Linux
> > I haven't noticed any performance hit. Box is Intel(R) Core(TM)2 Duo CPU
> > E8400 @ 3.00GHz with 4GB of memory. My stuff is mostly NOT cpu intensive,
> > but I do an occasional compile (LyX) and LaTeX large documents. No
> > observable change.
> It is there; the two common problems are that low memory fills, causing
> competition, and that your memory bandwidth is terribly reduced through
> TLB flushing to bounce data up above the easy line.
> You probably don't notice any performance hit because, frankly, almost
> computer you can buy — including the one in your mobile phone — is
> sufficiently overpowered for the work it is asked to do that you can
> sacrifice ten or twenty percent of performance without noticing.
That's interesting, Daniel. So what are my tradeoffs. Run the normal kernel:
faster but only 2.5gb; Run the bigmem kernel and suffer the performance but
have more memory.
Aside from the work mentioned above, I also edit some really big video files
and do ffmpeg transformations on them.
So, is there some way of choosing which of the above is the best option for
>  ...most of the time; 3D games and some science work do push the
> Most regular desktop use doesn't.
>  Typically, this is more than running the 32-bit bigmem kernel costs.
> ✣ Daniel Pittman ✉ daniel@xxxxxxxxxxxx ☎ +61 401 155
> ♽ made with 100 percent post-consumer electrons
> Looking for work? Love Perl? In Melbourne, Australia? We are hiring.
> SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/
> Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html