A ? about dual-channel DDR on the Athlon

[BurninMan921]

OK, I know how Dual-DDR works on the P4; if you have a 533MHz FSB chip, use two 266MHz DDR modules (2x266=533). But what about the Athlon XP? If I get a 333Mhz FSB XP chip, do I have to have 333MHz DDR memory? Or can I use the two 266MHz chips I currently have? Is there any performance differance between using the 266's instead of the 333's? Having dual-333Mhz chips would seem like overkill for a 333MHz FSB proc, but single channel DDR kills the XP's performance.

Since I want to use my current memory, would I be better off getting a Throughbreed chip (266MHz FSB) instead of the Barton? Both would be 2600+'s, and the Throughbreed might end up faster for me anyway since it has a higher clock and I do some things that are non-memory intensive, CPU-bound...

[wicked1]

In all the althon systems I've built using nvidia nforce2 boards you can run the memory at different speeds than the system bus, however the nforce2 boards do better with a 1:1 speed ratio. I would say buy the barton as it overclocks well and has more cache on it. I have a barton 2500 system overclocked to 3200 speeds rock stable its used as a small server system.I dont know what chipset mb you are using but the nforce2 can be very picky about what types of memory it will allow to go Dual channel. It took me a few tries to get a matched pair that would work right when the board first came out but now there are compatibility charts elsewhere on the net. I ended up buying 1 gig Crucial cause they guaranteed theirs would work.