OVCA Network specs – discussion with Oracle

Notes from meeting w/ Oracle on OVCA:

The most current version of Oracle Virtual Compute Appliance (VCA or OVCA) is X4-2
VCA consists of the following:
Infiniband (IB) QDR links operating at 40Gb/s bandwidth (raw fabric bit rate); effective maximum network throughput possible is in the order of 32Gb/s for data (due in part b/c 8b/10b used for encoding).
PCIe card limits (20-25Gb/s per server depending on server model)

VCA supports VLANs and can accept VLAN tags.

Virtual Machine (VM) network throughput is limited by various factors such as:
Expected Network throughput between Different Virtual Machines is as follows (from Oracle specs):

Between VMs running on same Compute Node: Approx. 15.5Gb/s
Between two pairs of VMs communicating running on the same Compute Node: 25.5Gb/s (with 12Gb/s-13Gb/s per client+server pair)

Between two VMs that runs on different Compute Nodes: Approx. 7.8Gb/s-8Gb/s
Between two pairs of VMs communicating running on different Compute Nodes: No reduction in speed.

Performance is affected by software layers and hypervisor/virtualization such as:
Xsigo drivers, EoIB and IPoIB add path length and latency.
Virtual Machine access adds further latency for virtual front and backend I/O devices
Private Virtual Interconnect (PVI) peer-to-peer communication vs. external traffic via Xsigo backplane