DragonFly kernel List (threaded) for 2003-11
Re: AMD64 impressions (Re: AMD64 box)
Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx> wrote:
> I was able to boot the AMD box with APMBIOS commented out (FreeBSD-4.x
> also can't boot the box with APMBIOS turned on either. I'll test
> FreeBSD-current later today).
> I ran some preliminary buildworld benchmarks. I don't have equivalent
> machines but a few things are obvious from the results:
> (1) The AMD box is very fast. Very, very fast. It blows away everything
> else hands down. It is so fast that it spends nearly 1/3 of its
> time waiting on I/O despite the fact that the I/O requirements
> for a buildworld are fairly minimal. It is so fast it makes my P4
> look like a snail, and even puts my DELL2550 (which is no slouch)
> to shame.
> The best comparison is the AMD box verse the P4 box. Both are UP
> boxes. The AMD box is 2.1x faster then the P4 box. If clock speeds
> scaled, that would make the AMD box equivalent to 2.6GHz P4. Since
> clock speeds don't scale, the AMD box is more like a 3.3GHz P4.
Opteron is easily the fastest commodity (that is, i'm discounting the huge-cache
Xeon variants) 32 bit processor. Compiling programs with icc (ironicly the best
Athlon compiler) makes it even more mindboggling fast.
> (2) The AMD's syscall overhead is very low compared to the P4.
> I ran the 'sc1' test in /usr/src/test/sysperf. The AMD box
> comes back at 242nS/loop while the P4 takes 1300nS/loop and
> the DELL box (LEAF/SMP) takes 617nS/loop.
ouch on teh p4 figure
> (3) I need to work on the SYS time for DragonFly SMP. LEAF's SYS
> time should be around 400s, not 961s. It's the SMP lwkt_token code
> being used for the vnode locks that is the likely culprit. LEAF
> is a 2xCPU DELL-2550 and no slouch (not like VALinux 2xCPU box which
> is a piece of junk). LEAF should have done better then it did.
+++ Out of cheese error +++