It remains to be seen whether this is a good thing or not. Redundant memory
means memory bandwidth scales with the number of GPUs. The 2x256-bit memory
interface on the 3870X2 is thus a close equivalent to a 512-bit interface.
This is how they quote the 115 GB/s bandwidth numbers. It's a benefit
recognized since the 3dfx Voodoo1 days. The benefit will be lost with shared
memory, though with high-clocked GDDR5 the pain will be less acute.

--
"War is the continuation of politics by other means.
It can therefore be said that politics is war without
bloodshed while war is politics with bloodshed."

"AirRaid Mach 2.5" wrote in message
...
You saw a little of that with the 3870X2, but the bridge was a simple
PCIe switch. The real magic this time is a bridge that shares memory,
GDDR5 in this case. Yup, you will have 2 GPUs with one set of memory.