Re: Memory performance significantly improved w/ 2.4.1ac11

From: Arvid Ericsson (
Date: Wed Feb 14 2001 - 08:39:56 EST

Mark Hahn skrev:
> first, are you sure your clock is write? the changes appear
> to be tiny ~2 MB/s, and might be explained by the fact that
> 2.2 and 2.4 have different implementations of gettimeofday.

The change I was happy about was the one between 2.4.0ac10 and
2.4.1ac11. I think that it's a good thing that a few percent more memory
bandwidth appears from nowhere... Well, but that's just me I guess.

> (I'm assuming you're using gtod (second_wall.c) rather than
> a times-based measure. the latter will be far less accurate.)

*Scratching my head* I have no idea of what your're talking about.
Sorry. Im using stream_whatever.cpp and whatever might be in it.

> are you also aware that more modern compilers (2.95.2, I think)
> have more specific CPU tunings than just -mpentium?

I just used the suggested optimizations.
> by "cycle length = 2", do you mean "tCAS latency = 2"?

Not quite sure, that the BIOS says "sdram cycle length=2" is all I know.

> finally (and don't take offense), those are astonishingly low
> Stream scores. it's been a while since I ran Stream on a p5-class
> machine, but jeeze! my dirt-cheap duron/600/kt133/pc133 sustains
> 600 MB/s!

Oh-well, I guess I just have a even dirt-cheaper machine than you. I
haven't got any idea of how machines similar to mine perform.


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This archive was generated by hypermail 2b29 : Thu Feb 15 2001 - 21:00:24 EST