X-bit labs

Rambus XDR2 to Operate at 8GHz.

Category: Memory

by Anton Shilov

[ 07/07/2005 | 08:21 PM ]

Even though XDR memory type developed by Rambus has not yet received mass adoption and devices utilizing it are yet to come, Rambus is already talking about its next development called XDR2. The firm believes its new memory technology will be used in devices requiring “extreme memory bandwidth” and will run at 8GHz.

“We are continually pushing interface technology forward to develop compelling and innovative solutions that meet our customers’ needs. XDR2 is our latest iteration of the XDR DRAM architecture and will help 3D games and graphics-intensive applications realize the high performance potential that users demand,” said Laura Stark, vice president of the Platform Solutions Group at Rambus.

While XDR2 is generally the same architecture as the XDR, it features several major enhancements, including the following:

• Micro-threading – a DRAM core innovation developed to increase memory system efficiency to enable DRAMs to provide more usable data bandwidth to requesting memory controllers, while minimizing power consumption;
• Adaptive Timing – a speed enhancement to today’s XDR FlexPhase timing circuits that compensates for process, voltage and temperature variations during real-time operation;
• Transmit Equalization – an output circuit that minimizes the adverse system effects of reflections and attenuation that typically limit the speed of DRAM systems;
• DRSL Signaling – a 200mV differential signaling standard that provides superior common mode noise rejection with an on-chip terminated point-to-point topology that minimizes reflections and reduced signal transition times associated with device loading and PCB trace stubs.

XDR2 memory interface is targeting apps that have tremendous memory bandwidth requirements, such as 3D graphics, advanced video imaging, and network routing and switching applications. XDR2 will work at 8GHz and above, which, in case of 16-bit interface provides 16GB/s bandwidth. By contrast, similar GDDR3 memory chip at 1.20GHz can pump up to 2.40GB of data per second.

Rambus engineers work closely with chip and system companies to optimize the DRAM controllers to take advantage of the performance benefits that the XDR2 solution provides. The XDR2 memory interface is available for licensing now and could be shipping in products by 2007.