Messages in this thread | | | Date | Fri, 15 Jul 2005 20:41:56 +1000 | From | kernel@kolivas ... | Subject | Re: [ANNOUNCE] Interbench v0.20 - Interactivity benchmark |
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Quoting Bill Davidsen <davidsen@tmr.com>:
> Con Kolivas wrote: > > >On Thu, 14 Jul 2005 03:54, Bill Davidsen wrote: > > > > > >>Con Kolivas wrote: > >> > >> > >>>On Tue, 12 Jul 2005 21:57, David Lang wrote: > >>> > >>> > >>>>for audio and video this would seem to be a fairly simple scaleing > factor > >>>>(or just doing a fixed amount of work rather then a fixed percentage of > >>>>the CPU worth of work), however for X it is probably much more > >>>>complicated (is the X load really linearly random in how much work it > >>>>does, or is it weighted towards small amounts with occasional large > >>>>amounts hitting? I would guess that at least beyond a certin point the > >>>>liklyhood of that much work being needed would be lower) > >>>> > >>>> > >>>Actually I don't disagree. What I mean by hardware changes is more along > >>>the lines of changing the hard disk type in the same setup. That's what I > >>>mean by careful with the benchmarking. Taking the results from an athlon > >>>XP and comparing it to an altix is silly for example. > >>> > >>> > >>I'm going to cautiously disagree. If the CPU needed was scaled so it > >>represented a fixed number of cycles (operations, work units) then the > >>effect of faster CPU would be shown. And the total power of all attached > >>CPUs should be taken into account, using HT or SMP does have an effect > >>of feel. > >> > >> > > > >That is rather hard to do because each architecture's interpretation of > fixed > >number of cycles is different and this doesn't represent their speed in the > > >real world. The calculation when interbench is first run to see how many > >"loops per ms" took quite a bit of effort to find just how many loops each > >different cpu would do per ms and then find a way to make that not change > >through compiler optimised code. The "loops per ms" parameter did not end up > > >being proportional to cpu Mhz except on the same cpu type. > > > > > > > >>Disk tests should be at a fixed rate, not all you can do. That's NOT > >>realistic. > >> > >> > > > >Not true; what you suggest is another thing to check entirely, and that > would > >be a valid benchmark too. What I'm interested in is what happens if you read > > >or write a DVD ISO image for example to your hard disk and what this does to > > >interactivity. This sort of reading or writing is not throttled in real > life. > > > > Of course it is. At least the read. It's limited to the speed needed to > either play (watch) the image or to burn it.
Ok we'll call it hair splitting. We do both. You read the file and I copy it. Both happen in real life, and I plan to emulate both.
Cheers, Con
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