On Tuesday, September 10, 2002, at 01:16 PM, Bernie Zenis wrote: Is anyone here familiar with Simultaneous Multithreading (http://www.cs.washington.edu/research/smt/)? Does anyone know if Darwin would lend itself well to SMT? For example, if a SMT PowerPC chip came out, would it be easy to port Darwin to it? I realize that might depend on what kind of SMT architecture was implemented. I have always felt that Darwin works best on an SMP machine. There are enough system threads, and multi-threaded applications to want two CPUs in many "peak" CPU utilization situations (my Mac OS X system typically has ~200 threads). I think the real world anecdotal evidence bears this out as well (most people with dual-ies are quite happy with the responsiveness of their machines, even when compared to single processor machines of quite higher clock rates). All of this is one of the reasons Apple ships all their PowerMacs as dual processor machines right now. The CPI numbers under most of those situations indicate that an SMT (others call it Hyper-threading) processor might do reasonably well compared to an SMP machine. But as you say, it all depends on the particular SMT design and other architectural factors on any given processor. --Jim _______________________________________________ darwin-kernel mailing list | darwin-kernel@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.