Help solve our dispute on Dual-Channel

[Patchworkblue]

Hey all-
A couple friends and I are having a lively about Athlon XPs and dual-channel memory. One of my friends says that Athlon XPs do not take advantage of any of dual-channel's benefits, and that the Athlon 64 FX is the first AMD cpu to do so. I was under the impression that the higher Athlon XPs, like 3000 and 3200, could derive some extra power from the dual-channel setup. Crashman, Poobah, help us out, yo. Any extra info on the subject would be cool, too.

Women--can't live with them, can't have heterosexual same-species intercourse without them.

 

[Crashman]

He's right in a way. The XP3200+ still has a 64-bit bus at DDR400, so a single module at DDR400 speed matches it perfectly. An additional channel would mostly go to waste.

nVidia does things a bit differently by stagering memory timings between the channels resulting in slightly less latency. That's the only performance advantage, and it's very small.

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[deadkenny]

Other potential gains (beyond the reduced latency) are when anything 'else' (other than the processor) uses the memory. So, for example, integrated video realizes a significant performance increase from dual channel memory. Or a DMA process would also benefit.

That (upgrade) which does not destroy you(r system's stability), makes it stronger. Nietzche

 

[kinney]

Dual Channel was really put on those boards for the IGP (integrated graphics). It really helps there.
As far as the processor it does help as Crash said, although very slightly.

If you check out the Anandtech single channel Nforce2 400 review (the little cousin to the NF2 Ultra 400, which is dual channel) you'll see they are for the most part, on par with each other.. the single channel sometimes even being a touch faster.
But overall not much difference in actual gaming.

XPs dont really need the extra bandwidth, I think they only can put to use 2.1GB/sec, something in that area.
Which single channel DDR266 can provide.

Though, the IGP gains GREATLY from dual channel (and the reason why Nforce2 has the fastest integrated graphics performance out there) and the memory timings are reduced.

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I just tell it like it is and some can't handle it. If your experience is different, well congratu-fukulation.
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