On Wed, 11 Jan 2006, Joachim Schrod wrote:
Hello,
I have a system with a Pentium P4 and an Intel D865GBF mainboard. The CPU has hyperthreading, but this is disabled in the BIOS. (The system got delivered that way. I bought it w/o any operating system.)
Nevertheless, SUSE 10.0 seems to detect Hyperthreading, since it uses an SMP kernel. Also, /proc/cpuinfo contains the lines
model name : Intel(R) Pentium(R) 4 CPU 3.00GHz stepping : 1 cpu MHz : 2993.250 cache size : 1024 KB physical id : 0 siblings : 2 core id : 0 cpu cores : 1
where -- as far as I understood -- a `siblings' line with a value >1 denotes hyperthreading.
So, is it necessary to enable hyperthreading in BIOS, or does Linux just ignore that setting and utilizes the CPU's full capabilities anyhow?
Yes, enable it if you want to take advantage of it.
However, of late there have been some interesting articles that suggest
that turning hyperthreading *off* may be faster than having it on.
--
Carpe diem - Seize the day.
Carp in denim - There's a fish in my pants!
Jon Nelson