In: Network I/O Latency on VMware vSphere , VMware White Paper 02/08/2012
Results are shown in Figure 4. VM-VM latency is in the range of 25 to 70 microseconds for different workloads. These results are slightly better than the latency observed for a VM-Native communication over 10Gbps link (Figure 2). It is higher than Native-Native latency because even though the small wire latency in Native-Native is replaced by memory-memory copy latency between two virtual machines, the overheads in virtualization mentioned in the “Introduction” section are still an additional source of latency.
Figure 4. Mean round-trip latency VM-VM
Note: the highest VM-VM data rate is <500Mbps (even at 20uS latency with 1024B packets
However in VMware vSphere 4.1 Networking Performance, April 2011 I find the VM-VM performance for 512B messages ~4Gbps?
Please help me understand what I am missing? For instance is the 4Gbps throughput for streaming transfers which would hide the latency?
thank you
MRLewin
