Re: [tlug] CPU speed: reported vs. actual

[Darren Cook <darren@example.com>]

>   1. Something in bios.

I had "Intel Speedstep" set on, so I switched it off. (CPU Frequency
Scaling Monitor complains on start-up.) Bios is saying it is 1.7Ghz.

The contents of /proc/cpuinfo now tell me:
  cpu MHz		: 1728.942
for all 8 processors. Everything else is the same.
But when I run the linpack benchmark it says:
  CPU frequency:    0.931 GHz
  ...
  20000  20016  4      843.847    6.3212   3.625560e-10 3.209415e-02

I.e. the time spent has doubled and GFLOPS has halved.

I'd think this meant I was now running at 900Mhz, and was actually
running at 1.7Ghz before, except Intel's own specs [1] say I should be
getting 27 GFLOPS.

(Temperature was 40-50 degrees when running the test this time; i.e. cooler)

Darren

[1]:
http://www.intel.com/support/processors/sb/CS-023143.htm#1