SMP kernel and dual Xeon's

daihard · 04-29-2006, 04:20 AM

Hi.

I am planning on installing FC4 on a dual-Xeon Dell computer. Since the Xeon CPU's have HyperThreading, it means the SMP kernel will see four virtual CPU's on this machine.

Could this cause any problems with kernel 2.6.16, which is the latest for FC4? I could disable HT so it will only see the two physical CPU's, but I'd like to be able to use the full capability of the processors if possible. Any advice?

TIA!
Dai

syg00 · 04-29-2006, 04:46 AM

All sorts of thoughts about H/T - some say it benefits, some not.
I think if I had (multiple) real CPUs, I'd be turning off SMT.

Best advice is to test it under *your* environment - if it works for you, use it.

daihard · 04-29-2006, 05:05 AM

Quote:

Originally Posted by syg00

All sorts of thoughts about H/T - some say it benefits, some not.
I think if I had (multiple) real CPUs, I'd be turning off SMT.

Best advice is to test it under *your* environment - if it works for you, use it.

Thanks for the advice. The computer in question is currently running XP Pro with HT enabled; i.e. XP sees 4 CPU's. I tested it with both HT on and off, and program compilation is quite a bit faster with HT on. That's XP, though I hope the same will be true for FC.

I'll try it myself. Thanks again.

syg00 · 04-29-2006, 06:05 AM

Then again ...
Have alook at this. A little old, but at least it's benchmark data. If you're looking to run a multi-threaded server box, maybe you'd be better off turning everything on ...

daihard · 04-29-2006, 01:20 PM

Quote:

Originally Posted by syg00

Then again ...
Have alook at this. A little old, but at least it's benchmark data. If you're looking to run a multi-threaded server box, maybe you'd be better off turning everything on ...

Thanks again for the useful info! I'll read up on it today.

Dai