OSS Introduces First PCIe 4.0 Backplane

Last week at NVIDIA's GPU Technology Conference (GTC), One Stop Systems introduced the industry's first backplane for PCIe 4.0. The OSS 5 Slot Gen 4 Backplane is a building block for high-performance computing applications, splitting one PCIe 4.0 slot into five.

The OSS 5 Slot Gen 4 Backplane uses one PCIe 4.0 x16 target slot and five PCIe x16 downstream slots. Those downstream slots can be connected to GPUs, NVMe drives, network switches and other accelerators such as FPGAs. Since it is PCIe 4.0 based, the backplane doubles interconnect bandwidth compared to PCIe 3.0 to 16 GT/s per lane, which translates to 256 GT/s or 32 GB/s in a single x16 slot.

Two OSS Gen 4 backplanes can be installed in OSS' 4U Value Chassis, making for a total of ten connections per box and 64 GB/s of bandwidth, making them suitable for HPC platforms. As a demonstration, OSS installed eight NVIDIA Tesla V100 GPUs in the 4U chassis. The V100s are PCIe 3.0-based, but they still benefit from the doubling of the bandwidth as PCIe 4.0 is backward compatible with PCIe 3.0, and GPU traffic from several GPUs are aggregated. 

Several major PCIe 4.0 platforms are due to arrive throughout the year. AMD's upcoming Zen 2 as well as Intel's Sunny Cove architecture in Ice Lake supports PCIe 4.0, although Ice Lake Xeon Scalable isn't set to launch until 2020. Thirdly, IBM's Power 9 was the first announced PCIe 4.0 system. There are also various PCIe 4.0 accelerators in the works, such as AMD's 7nm Radeon Instinct MI60 and future 7nm GPUs and Intel's upcoming 10nm Falcon Mesa FPGA, which was announced to start sampling mid-2019. 

While pricing was not announced, the OSS 5-way PCIe 3.0 backplane costs $1,625.