The Inquirer reports on Samsung’s new GDDR4 chips, which are currently undergoing testing.  If they deliver, they will double the bandwidth of current GDDR3 chips.
“The latency of the shipped modules is set at 0.8 nanoseconds, which limits the highest clockspeed of the memory to an astonishing 1.25 GHz in DDR mode. It does not take a braniac to calculate the possible bandwidth on G80/R580 boards: 32-bytes (256-bit) x 1.25 (GHz) x 2 (DDR) results in 80GB/s of theoretical bandwidth, almost double the currently shipping GDDR3 modules with ATI topping the GDDR3 charts with a 750MHz DDR clock on their R520XT baby.”

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