On 22-Mar-2002 David Wolfskill wrote:
> On a 0 - 10 "weirdness" scale, this ranks about a 4, perhaps, so it's
> hardly earth-shattering. But it's odd enough that I thought that a
> small reality check might be in order, in case the effect(s) in question
> were not expected. (And yes, I understand that a degree of uncertainty
> with respect to -CURRENT's performance is to be expected, even at the
> best of times. This is not a complaint.)
> Briefly, my SMP "build machine" built today's -CURRENT (while running
> yesterday's -- hence the Subject:) much more slowly than my laptop did.
> To illustrate, here are the timestamp messages from the respective
> kernel builds:
>>>> Kernel build for FREEBEAST started on Fri Mar 22 07:59:58 PST 2002
>>>> Kernel build for FREEBEAST completed on Fri Mar 22 08:24:19 PST 2002
>>>> Kernel build for LAPTOP_30W started on Fri Mar 22 08:09:25 PST 2002
>>>> Kernel build for LAPTOP_30W completed on Fri Mar 22 08:26:31 PST 2002
> So that's not a huge difference in and of itself -- 24:21 vs. 17:06 --
> but what really stands out is that the laptop actually finished the whole
> morning's processing before the build machine did. And that's somewhat
> remarkable, given that:
> * build machine got a bit of a head start (though it did have a little
> bit more work to do in one respect).
> * build machine is 2x866 MHz P3s; laptop is a 750 MHz P3.
> * laptop disk is 4500 RPM; build machine's disk is probably 5400 --
> certainly no slower than that.
> I don't really want to spam the entire list with the details of the
> processes used, so I cobbled up a page at
> http://www.catwhisker.org/~david/FreeBSD/speed.html that should
> have enough excruciating details for anyone sufficiently interested.
I saw some similar weirdness in my test machines last night where a dual
processor DS20 (Alpha 21264 500x2) beat out a PII Xeon 450x4. Normally the
quad xeon beats the DS20. The quad xeon was using -j16 but was about 74% idle.
The DS20 had used -j8. I didn't get a chacne to run top to see how it was
doing during hte world since I didn't notice the weirdness until last night
after the DS20 had finsihed but the quad xeon was still chugging along.
John Baldwin <[EMAIL PROTECTED]> <>< http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve!" - http://www.FreeBSD.org/
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