Messages in this thread | | | Date | Fri, 15 Jul 2005 08:50:08 -0400 | From | Bill Davidsen <> | Subject | Re: [ANNOUNCE] Interbench v0.20 - Interactivity benchmark |
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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.
-- bill davidsen <davidsen@tmr.com> CTO TMR Associates, Inc Doing interesting things with small computers since 1979
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