Memory maker Qimonda has begun sampling GDDR 5 video-memory chips, producing what it claimed today was the world's first 512Mb part.
Like past GDDR revisions, GDDR 5 ups the maximum available data transfer rate between video memory and GPU - to 20GB/s, in this case. Error compensation, adaptive interface timing and the ability to adapt the signalling characteristics to match patterns in the data being sent over the bus all contribute to the higher transfer rate.
Currently, the fastest GDDR 4 modules out there offer a throughput of up to 16GB/s. Qimonda preferred to compare its new GDDR 5 chip to GDDR 3, but that's because it's skipping GDDR 4 and going straight to 5.
Qimonda said the upgraded technology also delivers improved power consumption characteristics over its predecessors, though it didn't go into details. GDDR 5, like version 4, is set to 1.5V, but the c chips incorporate a number of techniques to reduce power consumption to below GDDR 4 levels, in part by slowing down unused memory.
Qimonda - the memory business spun out of Germany's Infineon, itself the chip-making off-shoot of Siemens - has a whitepaper on the subject that goes into much greater depth than we can here. You can find the PDF on the company's website.
The company said it expects to release GDDR 5 products commercially some time in 2008.