Gentoo Archives: gentoo-user

From: Mark Kirkwood <markir@××××××××××××.nz>
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] Symlinking /usr/portage/distfiles
Date: Wed, 31 Jan 2007 23:55:41
Message-Id: 45C12AED.2040109@paradise.net.nz
In Reply to: Re: [gentoo-user] Symlinking /usr/portage/distfiles by "Boyd Stephen Smith Jr."
1 Boyd Stephen Smith Jr. wrote:
2 > On Wednesday 31 January 2007 09:58, Alan McKinnon
3 > <alan@××××××××××××××××.za> wrote about 'Re: [gentoo-user]
4 > Symlinking /usr/portage/distfiles':
5 >> On Wednesday 31 January 2007, Bo Ørsted Andresen wrote:
6 >>> Furthermore Pentium 4 is a joke (it performs horribly). A 2 GHz
7 >>> (Dothan I presume) Pentium-M should be faster than a 2,8 GHz Pentium
8 >>> 4. My timing is for an 1,6 GHz (Banias) Pentium-M btw.
9 >> This sounds odd, but I'm not a cpu expert so can't really comment. Care
10 >> to elaborate on why the P4 performs so horribly?
11 >
12 > The instruction pipeline is very long, the CPU <-> RAM bandwith is quite
13 > small, and the pipeline has to be emptied any time the branch predictor is
14 > wrong. While the pipeline fills, the CPU works but no results are
15 > visible.
16 >
17 > Hz has never been a complete trump of other issues affecting CPU
18 > performance, but is always a factor to consider. (Among CPUs that are
19 > otherwise identical, higher Hz wins.)
20 >
21
22 Also Pentium-M has a lower latency L2 cache than P-4. With respect to
23 pipeline lengths I was curious to see what they actually were: P-4 has
24 20 stages, P-M has.. err... < 20 stages (Intel won't say exactly!).
25
26 I found this an interesting read for those of you interested in this:
27
28 http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2342&p=1
29
30 Cheers
31
32 Mark
33 --
34 gentoo-user@g.o mailing list

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