[Bug 429036] Re: core i7 i5 (Lynnfield) turbo boost not working

[Bacchus]

Elsie wrote "Bacchus said hardinfo CPU N-Queens is single threaded and
his result is 0.88s, but what i get is all 4 cores max out 100% @ 21x
with a result of 8.65s! any idea what's up?"

Try this, 
1) Shutdown compy, wait, turn-on computer.
2) Open hardinfo
3) Generate report
4) Post your results.

2.6.32 Kernel
Blowfish	           3.778
Cryptohash	   309.672
Fibonacci	           2.593   *
CPU N-Queens   0.887  *
FPU FFT		   1.516   *
FPU Raytrace	   5.811

2.6.31 Kernel (9.10 Default)
Blowfish              4.466
Cryptohash         252.071
Fibonacci            4.115
CPU N-Queens  1.540
FPU FFT             2.538
FPU Raytrace     21.473

As you can see the 2.6.32 has some MAJOR performance advantages when
using a CPU with Turbo Boost.   Especially the benchmarks denoted with a
*.  A side effect is that SMP programs do see a slight boost as well.  I
assume that as the program initially runs, the first thread will
throttle to max boost,.  The second thread that starts brings the 2
working cores to approx 80% max TB, and when all of my 8 cores kick in
I'm running 57% 1600/2800 of Turbo.

Elsie, I recommend (if not on a production machine) following my steps in post #36.  Skip step #1.  When you are installing the new kernel, make sure (when prompted), you install the maintainers version so grub will update with both kernels.  (You current kernel and the new one you are installing will be available for selection at boot.)  If everything works well then you can re-install all your modules / headers, etc.
Hope this helps!

-- 
core i7 i5 (Lynnfield) turbo boost not working
https://bugs.launchpad.net/bugs/429036
You received this bug notification because you are a member of Kernel
Bugs, which is subscribed to Linux.