Dual channel memory for video card?

[drdoom]

I was wondering if that is in the future at all? Memory speeds are pushing 1200mhz and there has to be some ceiling. Dual channel has helped CPU's why can't they do the same thing for GPU's. I guess it could be a problem cost wise. I for one don't want to see 1000USD video cards but doubling the bandwidth could be a good thing.

[ewitte]

Originally posted by drdoom
I was wondering if that is in the future at all? Memory speeds are pushing 1200mhz and there has to be some ceiling. Dual channel has helped CPU's why can't they do the same thing for GPU's. I guess it could be a problem cost wise. I for one don't want to see 1000USD video cards but doubling the bandwidth could be a good thing.

Usually they just increase the bus width for memory on video cards. Its easier to redesign the memory architecture because it is proprietary. For instance a 256-bit memory bus can handle 32bytes worth of date every clock cycle. Dual channel on the other hand is only equal to 128-bit memory. So your already getting only half the bandwidth. When you factor in the extra clock speed you get this:

Dual Channel - 6.4GB/s
6800 Ultra - 35.2GB/s

Eric

[Un4given]

High end video cards already use multiple channels. The 256-bit wide memory busses are actually 4 x 64-bit channels.

[drdoom]

That makes sense. But I would assume the more channels, the more traces on the board and the more money the board costs.

[Un4given]

Originally posted by drdoom
That makes sense. But I would assume the more channels, the more traces on the board and the more money the board costs.

Exactly.

[ATilaptops]

Originally posted by Un4given
Exactly.

Thus a gfx card with 256MB of RAM costs $400 and regular 256MB of RAM costs about $40. (IIRC most of the gfx card costs is because of the RAM too). Can you imagine if costs were comparable? We could have $100 6800GT's Or richer video card companys