Is amd phenom ii x4 920 faster than amd Phenom II X2 550 Black Edition Callisto

I am going to buy one or the other of these computers. Can anyone tell me which is a better and faster system setup for multimedia usage with Windows Vista Ultimate 64 Bit. I want a fast computer that never freezes or has to stop and think no matter what i'm doing.

AMD Phenom II X4 920 Quad Core 2.8 ghz - 4GB RAM - 750GB HD - ATI Radeon 3100

or

AMD Phenom II X2 550 Black Edition Callisto Dual Core 3.1 ghz - 4GB RAM - 750GB HD - ATI RADEON HD4200

It really depends. Simply on whether or not your applications can use more than 2 cores. Or if you plan on running many cpu intensive applications at one time.

The x2 is "faster" in apps that only use one or two cores. The x4 is faster in anything that uses more than 2 cores. I would go with the quad if i was you. But I wouldnt get the x4 920. I would jump up the x4 955.

By the way. I doubt your "freezes" is due to your hardware. Your machine even at FULL LOAD. should not freeze. Slow down, yes but it should not freeze.

If you want less slowdowns especially with multi-tasking I would recommend a quad core.