As Nvidia rolls out its GeForce 8800 GT graphics card and AMD prepares its riposte with Radeon HD 3800-series offerings, BetaNews reports that memory maker Qimonda has started sampling new GDDR5 graphics memory that's faster than anything on the market today.
According to Qimonda, the new 512Mbit GDDR5 memory chips being sampled are three times faster than 800MHz GDDR3 RAM, and they can achieve bandwidth of 20GB/s per module. If I've got my math right, that translates to "effective" DDR speeds of around 5GHz and total maximum theoretical bandwidth of 160GB/s for a graphics card with a 256-bit memory bus and eight GDDR5 chips.
To achieve such speeds without noise becoming an issue, GDDR5 memory operates with two clock types: a command clock and a differential write clock that runs at twice the frequency of the command clock. The memory also implements cyclic redunancy checks to detect transmission errors. More information about GDDR5's new features is available in Qimonda's GDDR5 white paper.