As you may aware, significant improvement had been done on the latest hypervisor from VMware vSphere 4.1.
1 of the key changes are the vCPU for each virtual machine with latest NUMA hyperthreading architecture.

I found a very details and great post talk about this topic, please read the full post from here.

This will significant improve the Consolidation ratio and performance over the virtual machine VS the previous version ESX 4.0.

VMware had officially released the vSphere 4 update 1 yesterday. There are many new support features and also bug fixes. Is time to take a look for a major upgrade this month to overcome some challenges we faced with the previous version.

Please view more information from the release note.

Beside the bug fixes, there are some new key highlight here too.

VMware View 4.0 support – This release adds support for VMware View 4.0, a solution built specifically for delivering desktops as a managed service from the protocol to the platform.

Windows 7 and Windows 2008 R2 support –Officially Supported both windows 7 and 2008 R2 for 32 bits and 64 bits. The previous issue for the viclient that could not run on Windows 7 had been solved

Enhanced Clustering Support for Microsoft Windows – Microsoft Cluster Server (MSCS) for Windows 2000 and 2003 and Windows Server 2008 Failover Clustering is now supported on an  (HA) and (DRS) cluster in a limited configuration.

Enhanced VMware Paravirtualized SCSI Support – Support for boot disk devices attached to a Paravirtualized SCSI ( PVSCSI) adapter has been added for Windows 2003 and 2008 guest operating systems

Improved vNetwork Distributed Switch Performance – Several performance and usability issues have been resolved resulting in the following:

• Improved performance when making configuration changes to a vNetwork Distributed Switch (vDS) instance when the ESX/ESXi host is under a heavy load
• Improved performance when adding or removing an ESX/ESXi host to or from a vDS instance

Increase vCPU per Core Limit – The limit on vCPUs per core has been increased from 20 to 25. This change raises the supported limit only. It does not include any additional performance optimizations.

Configure 5 Vcpu for the VM

Task Manager in Windows show 5 cores are active

Summary Tab shows 5 vcpu had been assigned. In physical Server environment, we will usually start with 1 cpu, 2 cpus, 4 cpus, 8 cpus and etc. This features from vmware vSphere is really helpful and allow us to control and prevent over provision to the virtual Machine

The reason of virtualizing today, is really not about sacrifice performance. In our environment, we have most VMs running with 4 Vcpu as the result of customer compare VM to Physical Servers to ensure the performance is sustainable or improve when they switch to VM. When the VM itself is idle or less busy, it will not consume too much resources on the Physical CPU cores. Next release of ESX will go for 8Vcpu per VM. The number of Vcpu been assigned to the VMs which require extra CPU resources will increase too.

Updated: Configuration Maximums for VMware Infrastructure 3 – Number of Virtual CPU = 192

But if we compare the technology today, I believe most of us will see that from virtual cpu perspective, VMware had been quite slow respond on that. If you do spoke to most of the VMware representative or consultant, they always told you not to allocate more than 1 Vcpu if not required.

In real world, I believe that non of us will be satisfied with the single core performance for our server environment. Dual core is been in the market for more than 2 years, and quad core had been also popularize to most of us. Single core will just be SLOW in most of the event. I am here to urge VMware to push harder for more virtual CPU per VM. The thing that should consider is to compare with the competitor products like Xen and Xensource.

In Xen, you will allow to configure 8 vcpu per VM if your host have 8 cores. That meant you should able to configure 16 cores per VM if your host do have 4 x quad cores today. I am yet to test with 16 cores per VM as my machine is come with 2 x quad cores.

I even try to run a VM with Windows 2008 which contains 8GB memory and 8 virtual cpu assign. The VM is run on local storage on the SATA disk. The performance on the VM is just fast compare to 4 vcpu VM I had in ESX. Again, not to say VMware is not good, and I strongly believe VMware is still the best today, but they are little behind with the delay of more vcpu per VM.