AMD Radeon HD 7900 to Utilize New XDR2 Rambus Memory

Based on a leaked road-map, AMD will be releasing their new GPUs in Q4 for the upcoming holiday season. The GPUs will start with four different GPUs based on the 28nm version of the VLIW4 (Very Long Instruction Word) architecture. The four GPUs will be equipped with 768 to 1536 Radeon cores (stream processors) and GDDR5 memory.

The fun begins when you start to look at the new high-end GPUs codenamed "Tahiti", which is expected to see a Q1 2012 release. The "Tahiti" will make use of PCIe Gen3 interface, which has a massive bandwidth of 32 GB/s. The 7900 series is set to utilizes new AMD's Graphics CoreNext GPU architecture. The GCN is expected to boost performance per square millimeter die area to improve upon the VLIW4 architecture .

The most interesting change is AMD's decision to go with XDR2 memory interface from Rambus over previous generation DDR5 memory interface. Rambus claims the XDR2 is twice as fast as DDR5, while offering 30 percent less power consumption.

Read more about Rambus' claim.

Additional information leaked has the Radeon HD 7970 series with, 2048 Radeon Cores, GPU frequency of 1000 MHz and XDR2 memory at 8000 MHz, which would result in a memory bandwidth of 256 GB/s over a 256-bit memory interface. This compared to the 176 GB/s in Radeon HD 6790 with GDDR5 memory at 5500 MHz. All this power will be packed within an estimated power consumption of 190 watts

There looks to be some interesting times ahead for AMD in the coming months for us to keep watch. AMD will be releasing its new "Bulldozer" architecture, along with the new GCN architecture for the 7900 series GPUs (if the information leaked is accurate).