How to reproduce: Re: Only 70% of theoretical peak performance on FreeBSD 8/amd64, Corei7 920

Wed Apr 14 16:45:05 UTC 2010

On Wed, Apr 14, 2010 at 11:34 AM, Adam Vande More <amvandemore at gmail.com>wrote:

>
>
>
> That's about 67% utilization, turning off HTT drops it more.  HTT on the
> newer cores is good, not bad.
>

Well that was completely contrarty to some tests I'd run when I first got
the cpu.

With HTT off:

n: 3000
time : 44.705516 or 11.760183
Mflops : 45932.959253
n: 3100
time : 50.598581 or 14.270123
Mflops : 41766.437458
n: 3200
time : 55.748192 or 15.780977
Mflops : 41541.458400
n: 3300
time : 62.072217 or 17.441431
Mflops : 41221.262070
n: 3400

so that's about 79% right there.

also if I run cpuset on the dgemm then the utilization is basically at the
theoretical max for one core so at least that part is working.

-- 
Adam Vande More