Current SMP System vs. a Single CPU System?

[JohnDoemakt]

zachj : Won't the Pentium D perform a bit worse than Xeons as the two cores share one 800 MHz FSB and the Xeons have one each?
But you're right, the price will make that platform pretty tempting until AMD get their pricing right.

I only hope dual core Xeons and Opterons wont go back to having a 200% price premium.

 

[zachj]

The Xeon architecture shares the bus just the same as the dual-core pentium. Each is separately connected to the Northbridge, yes, but they both vie for access to RAM on the single 800MHz bus. If you turn off hyperthreading on a Xeon, I'd wager you're about 1% away from performance of a single dual-core Pentium of the same clockspeed. That 1% assumes that the two processors can talk between one another without going through the northbridge . . . If they can, then that communication would be faster because they're closer together, but I somehow doubt that's how they work. Pictures of the processors seem to indicate two separate cores on one package, so I'm willing to bet some money that it's 100% the same as a dual Xeon without HT. I think AMD and Intel have screwed the pooch on this one, since there's now no reason to go with dual processors. I think they're going to find themselves in the place of having to reduce prices to get the stuff to sell.

Z

 

[Elif Tymes]

Well, AMD did thiers slightly different, I beleve they enable core to core communication, which will be rather nice.

 

[JohnDoemakt]

AMD's dualcores will be "real" dualcores with an arbiter that will increase performance over dual singlecores, but that performance edge is lost with their high cost.