A hyper threaded processor is only a single core CPU. Its more marketing than performance, however you might as well run an SMP kernel on it just 'cause you can ;-) When you upgrade to your twin Core Opterons, now that would be a good machine to run an SMP kernel on P. Paul Heinlein wrote: > On 4/20/05 9:09 AM, Aleksandar Milivojevic wrote: > >> BTW, do note that HT processor still has only single core. Some >> reports indicate that there's not much advantage of HT over non-HT >> processors (and consequently not much advantage of running SMP kernel >> on HT processor). > > > Fully realizing that the plural of "anecdote" is not "data," I can > report that enabling HT and running an SMP kernel speeds up parallel > make operations by 15-20%. E.g., running "make -j2" on P4/HT/SMP is > slightly faster than "make -j2" on the same processor running a UP > kernel. It seems like the SMP kernel is better able to keep the core > busy than the UP kernel. > > Other operations, particularly day-to-day desktop stuff, seemingly > don't benefit much at all. >