Daniel Robbins <[EMAIL PROTECTED]> writes: > On Mon, Jul 14, 2003 at 03:22:06PM +0200, Terje Kvernes wrote: > > > ordered a dual 1.8Ghz Opteron to do numbercrunching. we've also > > bought a dual 3.06Ghz P4 Xeon with HyperThreading to compare it > > with, but there is very little doubt that the Opteron will come > > out first. > > I wouldn't make that assumption. I could very easily see the dual > Xeon outperforming the dual Opteron -- make sure to test the > specific application first. In fact, I would wager that the dual > Xeon will outperform the Opteron in most situations, based on my > experience.
we're mostly talking about locally produced pieces of Fortran running over rather large datasets for a few days or weeks at a time. we're looking at mostly floating point and a few other tidbits. from what I've seen of similar tests, there is little doubt that the Opteron will be a nice tool for the task. > The Opteron 240 seems to be performing somewhere between an XP 2000+ > and XP 2200+; not even up to Athlon MP levels yet -- based on my > testing, which is by no means exhaustive. And hyperthreading can > make a very significant difference for many types of loads, too. for our general case, HyperThreading gives almost nothing in the best case. worst case, it actually costs us some percent here and there. this is, of course, a known issue. we're not talking about desktops running your-favorite-WM here. :-) > Be sure to benchmark what you are actually going to be using the > machine for. A lot of us work under the assumption that "64-bit is > faster," and that's not necessarily true. that much we know. but, there is a reason why you'll still see people running certain calculations on old Alphas, because they're still the best ting for certain things. Opteron isn't a desktop winner. it's a decent performer for such tasks, but not a winner. for certain types of numbercrunching though, all tests I've seen point towards a nice big boost. Portland Group has some small tidbits about 64bit Fortran if one is interested. :-) (and no, I don't do Fortran, I just like to test hardware. :-) -- Terje -- [EMAIL PROTECTED] mailing list
