14 DAY TRIAL // A Silicon Valley company just announced that they started shipping a FPGA based coprocessor designed to be used on a socket 940 multiprocessor motherboard that is normally used to house one or more AMD Opteron processors. DRC Computer says that its RPU (reconfigurable processing unit) eliminates bottlenecks like limited bandwidth and increased latency normally associated with co-processors in super computing applications.
The RPU connects a "field programmable gate array"( FPGA for short) directly with the host system's HyperTransport bus (an upgraded AMD specific processor bus) in order to obtain more bandwidth and a big drop in latency times compared with other co-processor interfaces like PCI and Ethernet. As a bonus for a really bandwidth processor, each RPU can be configured to sustain three HT connections, for a total bandwidth of 9.6Gbps. Depending on the application this new technology can help increase the speed 10 or 20 times as compared with software running on a single general purpose processor. Coupling an FPGA tightly to a general purpose processor and main system memory means that only processor-intensive subroutines have to be synthesized onto the FPGA, DRC said. Other touted benefits include lower power, cooling, and footprint requirements, compared to off-board coprocessors.
In addition to 1-3 HyperTransport logic units, each RPU integrates a pair of DDR2 memory controllers. One tightly couples the RPU to main system memory, while the other interfaces with 1GB or 2GB of DDR2 RAM built right into the RPU itself. With 8GB of system memory, and 2GB of RPU memory, system memory bandwidth can reach 17GB/second, DRC claims, as cited by Linuxdevices. The initial RPU model, the RPU110, is available with a choice of three FPGAs, including Xilinx's Virtex LX 100, LX 160, or LX 200. The FPGAs clock up to about 400MHz, according to DRC spokesperson Giang Le, and are the largest FPGAs available.
The supercomputer vendor Cray, which offers the co-processor as an option for theXT3 line is a well known advocate of the RPU unit. The Cray company can deliver a XT3 rack with 96 RPUs and 48 Opteron processors. Clay Marr, VP of marketing at DRC, said that, "Markets such as financial services, oil and gas, and life sciences are demanding more powerful computing from their standards-compliant systems but also want to conserve energy."