On 2/11/2010 2:00 AM, Edwin Bennink wrote:
Dear gcc list,
I noticed that starting an OpenMP parallel section takes a significant
amount of time on Nehalem cpu's with hyper-threading enabled.
If you think a question might be related to gcc, but don't know which
forum to use, gcc-help is more appropriate. As your question is whether
there is a way to avoid anomalous behaviors when an old Ubuntu is run on
a CPU released after that version of Ubuntu, an Ubuntu forum might be
more appropriate. A usual way is to shut off HyperThreading in the BIOS
when running on a distro which has trouble with it. I do find your
observation interesting.
As far as I know, the oldest distro which works well on Core I7 is
RHEL5.2 x86_64, which I run, with updated gcc and binutils, and HT
disabled, as I never run applications which could benefit from HT.
--
Tim Prince