On Wed, Oct 20, 2004 at 07:16:18PM +0100, Matt Clark wrote: > ><OT> > >Hyperthreading is actually an excellent architectural feature that > >can give significant performance gains when implemented well and used > >for an appropriate workload under a decently HT aware OS. > > > >IMO, typical RDBMS streams are not an obviously appropriate workload, > >Intel didn't implement it particularly well and I don't think there > >are any OSes that support it particularly well. > ></OT> > > > >But don't write off using it in the future, when it's been improved > >at both the OS and the silicon levels. > > > > > > > You are quite right of course - unfortunately the current Intel > implementation meets nearly none of these criteria!
Indeed. And when I said "no OSes support it particularly well" I meant the x86 SMT implementation, rather than SMT in general. As Rod pointed out, AIX seems to have decent support and Power has a very nice implementation, and the same is probably true for at least one other OS/architecture implementation. > As Rod Taylor pointed out off-list, IBM's SMT implementation on the > Power5 is vastly superior. Though he's also just told me that Sun > is beating IBM on price/performance for his workload, so who knows > how reliable a chap he is... ;-) :) Cheers, Steve ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster