One feature of the usNIC ultra-low latency Ethernet solution for the UCS Cisco VIC that we think is interesting is the fact that it is based on SR-IOV.
What is SR-IOV, and why is it relevant in the HPC world?
SR-IOV (Single Root I/O Virtualization) is commonly used in the server virtualization world. The most commonly described purpose of SR-IOV in the hypervisor world is to allow a device partition, called VF (Virtual Function), to be mapped in the guest operating system address space. This allows the guest operating system to enjoy higher I/O performance and lower CPU utilization as compared to the alternative: software-emulated devices that are traditionally implemented in hypervisors.
Compared to the old world before hypervisors came along, that use of SR-IOV seems to allow to regain back some performance lost due to the hypervisor software intervention in the I/O data path. But why should I care about SR-IOV in the world of my network-latency-bound HPC applications running on common operating systems on bare metal servers?