I do notice that on my dual P4 Xeon machine, two instances of P95 are running like a champ. Normally on my other dual CPU systems, the rolling average will slip from the normal 1000 to around 900 or so. But on the dual Xeon with both physical CPU's running, the rolling average has only slipped to about 990 or so. This is on a Proliant ML530 mind you, so the memory subsystems and all that are, IMO, better than any other multiprocessor X86 machine. :)
The neat thing is that because of my two "phantom" cpu's running, each P95 instance doesn't really have to give up as much CPU time when there's other stuff going on. For instance, I'm running MSSQL on the same machine and it makes use of the 2 real CPU's and the 2 phantom ones, so P95 doesn't have to give up as much CPU time apparently. On a single CPU system, you would probably see the same benefits, where P95 simply runs better because the phantom CPU is there to take up some of the normal user type things... Windows kernel stuff and other simple integer processes. YMMV, but I'm pretty pleased with what I see. As for running multiple P95 instances on a single physical CPU, forget about it. :) But running one copy, you might just get better performance out of your system this way. Aaron > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED]] On Behalf Of > David Underbakke > Sent: Sunday, January 05, 2003 3:28 PM > To: [EMAIL PROTECTED] > Cc: Terry S. Arnold > Subject: Re: Mersenne: P4 Hyperthreading > > > At 03:04 PM 1/5/2003 -0800, Terry S. Arnol wrote: > >Does Hyperthreading have any significant performance impact > on Prime95? > > > > This issue was discussed on this list around March of 2002. > I believe the results were that Prime95 is so efficient that > hyperthreading has no performance improvement or benefit for > a computer running Prime95. > > Prime95 has no pipeline stalls that a second hyperthread > could efficiently utilize. > > ___________ > > David Underbakke > > > ______________________________________________________________ > ___________ > Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm > Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers > _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
