Re: [gentoo-user] Symlinking /usr/portage/distfiles

[Mark Kirkwood <markir@paradise.net.nz>]

Boyd Stephen Smith Jr. wrote:
> On Wednesday 31 January 2007 09:58, Alan McKinnon 
> <alan@linuxholdings.co.za> wrote about 'Re: [gentoo-user] 
> Symlinking /usr/portage/distfiles':
>> On Wednesday 31 January 2007, Bo Ørsted Andresen wrote:
>>> Furthermore Pentium 4 is a joke (it performs horribly). A 2 GHz
>>> (Dothan I presume) Pentium-M should be faster than a 2,8 GHz Pentium
>>> 4. My timing is for an 1,6 GHz (Banias) Pentium-M btw.
>> This sounds odd, but I'm not a cpu expert so can't really comment. Care
>> to elaborate on why the P4 performs so horribly?
> 
> The instruction pipeline is very long, the CPU <-> RAM bandwith is quite 
> small, and the pipeline has to be emptied any time the branch predictor is 
> wrong.  While the pipeline fills, the CPU works but no results are 
> visible.
> 
> Hz has never been a complete trump of other issues affecting CPU 
> performance, but is always a factor to consider.  (Among CPUs that are 
> otherwise identical, higher Hz wins.)
> 

Also Pentium-M has a lower latency L2 cache than P-4. With respect to 
pipeline lengths I was curious to see what they actually were: P-4 has 
20 stages, P-M has.. err... < 20 stages (Intel won't say exactly!).

I found this an interesting read for those of you interested in this:

http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2342&p=1

Cheers

Mark
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