In this chapter
- The NT200C01 solution consisting of two NT100E3-1-PTP accelerators.
- A pair of NT40A01-4×10/1-SLB accelerators.
QPI bypass concept
QuickPath Interconnect (QPI) provides fast connections between multiple processors and I/O hubs.
Direct Data I/O (DDIO) is an enhancement of DMA that allows data to be transferred directly between a device in a PCIe slot and the L3 cache of the processors local to the PCIe slot.
The local L3 cache is polluted by data destined for the remote NUMA node.
The QPI itself causes latency.
The QPI memory write causes a flush of remote L3 cache lines (enforced by the cache coherency protocol).
- In the NT200C01 solution, two NT100E3-1-PTPs can be bonded as peers so that streams can be redirected to the peer accelerator.
- A pair of NT40A01-4×10/1-SLB accelerators can be bonded in a master-slave configuration so that all frames received on the master accelerator is copied to the slave accelerator.