Hi All
I am about to schedule some work to increase the size of my ESX 4.1 cluster. I currently have 2 host (DELL R620's) and I am going to add another 2 of the same model servers. The new servers have a different only in CPU's but the same generation.
Should I bother enabling EVC on my cluster prior to importing the 2 hosts? My feeling is no but I wanted to put it out there to people who know more than I do. My highest level of EVC compatibility is Westmere.
EVC is currently disabled
Sandy Bridge CPU's
| Model | sSpec | Cores | Frequency | Turbo | L2 | L3 | TDP | Socket | I/O bus | Memory | Release date | Part |
| number | number | number(s) | ||||||||||
| Xeon E5-2650 | SR0KQ (C2) | 8 | 2 GHz | 4/4/5/5/5/7/8/8 | 8 × 256 KB | 20 MB | 95 W | LGA 2011 | 2 × 8.0 GT/s QPI | 4 × DDR3-1600 | March 6, 2012 | CM8062100856218 |
| SR0H4 (C1) | CM8062100856218 | |||||||||||
| SR0KQ (C2) | BX80621E52650 | |||||||||||
| Xeon E5-2660 | SR0KK (C2) | 8 | 2.2 GHz | 5/5/6/6/7/7/8/8 | 8 × 256 KB | 20 MB | 95 W | LGA 2011 | 2 × 8.0 GT/s QPI | 4 × DDR3-1600 | March 6, 2012 | CM8062107184801 |
| SR0GZ (C1) | CM8062107184801 | |||||||||||
| SR0KK (C2) | BX80621E52660 |
Plz read below lines: It is worth to read :
It is often the case that an older release of vSphere supports a new processor but not the corresponding new EVC baseline that exposes the maximum guest-visible features of that processor. A newer vSphere release usually supports both the processor and the new EVC baseline. This is because the older release can only support those features of the new processor that are in common with older processors. Therefore, support of an EVC baseline is not identical to the support of the corresponding processor. Tables 2.1 and 2.2 indicate the earliest vSphere release that supports each EVC baseline.
As an example, consider the Intel® “Sandy Bridge” Generation EVC baseline and the Intel® Xeon e5-2400 (a processor based on the Intel® “Sandy Bridge” architecture). The processor is supported by both vSphere 4.1 Update 2 (and later) and vSphere 5.0 (and later). But because vSphere 4.1 update 2 lacks support for advanced “Sandy Bridge” features such as AVX, the Intel® “Sandy Bridge” Generation EVC baseline is only supported starting with the vSphere 5.0 release. However, vSphere 4.1 Update 2 does support lower level EVC baselines on the Intel® Xeon e5-2400, such as Intel® “Westmere” Generation and Intel® “Merom” Generation.
Now you might have got clear idea on why EVC compatibility mode is westmere even when CPus are from sandy bridge.
As per me, in you case EVC is not required as feature set/instruction set in both the CPU are same. Just some difference in clock speed/performance.
Ref: Intel Xeon E5-2660 vs E5-2650
I am not sure I am following your query:
The CPU details that your have given are from Sandy bridge (I believe these are from new hosts) & you specified highest level of EVC compatibility is westmere. Can you post CPU details @earlier hosts?
What happens when two different CPUs are at source & destination
When a guest OS is running on a CPU with a certain instruction set, the guest OS will crash with a kernel panic or a Blue Screen of Death (depending on if you're running Linux or Windows) when the extra instructions suddenly become unavailable – which is what happens when you attempt to VMotion from one type of CPU to another type of CPU.
Worth to read KB :VMware KB: EVC and CPU Compatibility FAQ
The fist listed CPU's are with the current hosts in the cluster E5 2650 (Sandy Bridge Generation)
the second listed CPU's are what is in the new hosts I want to add. E5 2660 (also Sandy Bridge)
I am running ESX 4.1 with EVC disabled. If I enable it I can go as high as the Westmere level.
should I need to enable EVC to add these new hosts to my cluster or can I just leave it disabled.
Plz read below lines: It is worth to read :
It is often the case that an older release of vSphere supports a new processor but not the corresponding new EVC baseline that exposes the maximum guest-visible features of that processor. A newer vSphere release usually supports both the processor and the new EVC baseline. This is because the older release can only support those features of the new processor that are in common with older processors. Therefore, support of an EVC baseline is not identical to the support of the corresponding processor. Tables 2.1 and 2.2 indicate the earliest vSphere release that supports each EVC baseline.
As an example, consider the Intel® “Sandy Bridge” Generation EVC baseline and the Intel® Xeon e5-2400 (a processor based on the Intel® “Sandy Bridge” architecture). The processor is supported by both vSphere 4.1 Update 2 (and later) and vSphere 5.0 (and later). But because vSphere 4.1 update 2 lacks support for advanced “Sandy Bridge” features such as AVX, the Intel® “Sandy Bridge” Generation EVC baseline is only supported starting with the vSphere 5.0 release. However, vSphere 4.1 Update 2 does support lower level EVC baselines on the Intel® Xeon e5-2400, such as Intel® “Westmere” Generation and Intel® “Merom” Generation.
Now you might have got clear idea on why EVC compatibility mode is westmere even when CPus are from sandy bridge.
As per me, in you case EVC is not required as feature set/instruction set in both the CPU are same. Just some difference in clock speed/performance.
Ref: Intel Xeon E5-2660 vs E5-2650
Thanks for your input
I appreciate your time and effort. its what I was thinking but it is good to get another opinion.
