vSphere 4.1 Performance Improvements
VMware published an excellent whitepaper detailing the performance improvements introduced in vSphere 4.1. The paper is 14 pages long so here’s a quick breakdown for those who want just a quick summary.
vSphere 4.1 is about 3 times more scalable than vSphere 4.0 as noted in the following table
WIDE VM NUMA
New CPU efficiencies available when using NUMA enabled hardware can significantly improve performance in high workloads
It is actually faster to compress a memory page than to swap it to disk. The size of this cache is configurable. The performance gain depends on the extent memory overcommittment is used. VMware claims a 15% improvement for moderate overcommitment and 25% for heavy overcommittment.
STORAGE I/O CONTROL
I discussed this in an earlier post and again here. This feature will allow the administrator to set a preference for I/O on a per VM basis such that greater performance can be made available for specific VMs. In short, mission critical VM’s can be granted a higher preference for I/O activity.
STORAGE PROTOCOL IMPROVEMENTS
- 8GB FC HBA Support
- NFS Performance Improvements
- iSCSI Performance Improvements
- 10% improvement in VM to wire transmit speeds
- 100% improvement in VM-to-VM transmit speeds
- Large Recieve Offload (LRO) for Linux Guests
- 3.6x improvement in VM Fault Tolerance traffic throughput
Many of the vSphere 4.1 performance improvements will be especially relevant to VDI environments as noted in the paper.
- A 3x improvement on 10GbE links
- Storage vMotion up to 25% faster
- Registering and reconfiguring VM’s is as much as 3x faster than vSphere 4.0
STORAGE PERFORMANCE MONITORING
This is one of my favorites as the new metrics can be very valuable in troubleshooting SAN performance issues. Latency metrics are now collected from many different perspectives, including hosts, datastores, VMDK’s, SAN paths, and more.