Re: kernel compile time comparison (2.0 vs 2.1 with 64MB)

Andrew Derrick Balsa (andrebalsa@altern.org)
Mon, 3 Aug 1998 13:19:00 +0200


Hi Peter,

On Mon, 03 Aug 1998, Peter T. Breuer wrote:
....
>
>I almost feel like varying the parameters one at a time :-).

This would allow seeing the effects of each parameter on compilation times. It
is also the recommended procedure in m HOWTO... :-)
>
>Kernel compilation seems cpu and/or memory bound, and the measurements
>seem to indicate that the measurements that I make don't distinguish the
>two.

It's hard to tell unless you keep the other parameter constant, and in the case
of the Celeron oc.@412MHz vs. PPro200, this is impossible. The Celeron has a
small 32KB L1 cache and that's it. The PPro has both an L1 cache and an L2
cache (you didn't say but I assume it is the more common 256KB model).

You could try _underclocking_ the Celeron at 200MHz, but IIRC this is
impossible too: the Celeron has a fixed multiplier.

However the PII and the Celeron have basically the same core. Comparing
compilation times on a PII @ 300MHz vs. the Celeron @ 300MHz will clearly show
the effect of the 512KB L2 cache on the PII core performance, during kernel
compilations (keeping other factors constant).
....
>Well, three years of hardware development ought to make a difference
>that is noticable with your eyes shut. I have to say, no, not really.
>I still run a 486 dx 33MHz quite happily as an X terminal, with 32M
>memory. I can't say it's slower at anything except kernel compilation.
>It benchmarks about the same at that as a couple of old sparc's I have.
>They have wonderful disk i/o. But putting ram in the 486 levels it out.

There are various bottlenecks in PCs. Running the 486DX-33MHz as an X
terminal, you may notice only slightly slower keyboard/screen response times
(no disk i/o), compared to, say, a 486DX4-100MHz.

But really, a faster CPU makes a noticeable difference in everyday use.

Cheers,

--
Andrew D. Balsa
andrebalsa@altern.org

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