socket 754 and dual channel memory

[Spase]

Hey Fozzik. I have been looking around at some of my options for building a system, and noticed that the 754 mother boards dont seem to have dual channel memory listed at all. I find this a bit surprising as my socket A board has dual channel. I would think that the dual channel design would be easier to find in the newer technoogy. I also see it listed on some(but not all) 939 mother boards, so it doesn't look like its a hyper-transport thing, though that would otherwise be my theory - that the dual channel and hyper-transport were almost the same thing. Do you know anything about this?

I'm pretty sure I'll go with the socket 939 for my build when I get there, its just been nagging at me so I thought I would ask.

[Fozzik]

With the design of the Athlon 64, the memory controller was moved onto the processor...and so it has less to do with the motherboard these days than it does the CPU, and the number of pins it has to connect to the rest of the system.

Socket 754 has always been single channel, because there aren't enough pinouts for two memory channels. The processors that go onto socket 754 all have single-channel memory controllers.

Socket 939 added the extra pins needed for dual-channel, as well as more power pins for a larger amperage spec. All the processors (with the possible exception of some low-end value-based semprons or something I'm forgetting) that plug into 939 have a dual-channel memory controller onboard.

Hypertransport is something separate... it is the bus that connects the Athlon 64s to the rest of the system... via the motherboard chipset.

[Breogan]

Socket 939 Semprons have dual channel too, but they are only available to certain builders like HP, etc. It's a shame because someone posted a few screenies of one and it overclocked like a beast.
I think AMD posted in their roadmap some Socket 939 Semprons for the next year, probably by the time Socket M2 appears.