Modifying baseline instruction set in EVC Cluster

[ssbangal]

Hi,

When configuring the EVC cluster, the baseline instruction set that the EVC cluster appies is that of "Merom" based systems (baseline feature set of Intel core 2 processors). Having this configuration would be of great help if we have a combination of both Merom-based systems and Penryn-based (next generation) systems.

But if in case I have just Penryn based systems, with the above setting, i will not be able to take advantage of the SSE4.1 instructions that are available in Penryn-based systems.

Is it possible to change this configuration to use Penryn-based instructions as the baseline set instead of Merom-based?

Regards,

Sudhir

[lamw]

I believe you can just create a new cluster and have it enabled with EVC with the Penryn-based host and then add the other hosts into the cluster. If they're compatiable by default, EVC should configure the baseline to work with both those arch. Have you tried to add your "peryn-base host" into the current "merom" cluster to see if it works or is this a question posed before attempting to create your EVC cluster?

[ssbangal]

Actually I don't have any issues creating the cluster at all. I can create and add either merom-based or penryn-based or both kinds of servers. Everything works fine.

But my question is that if in my EVC cluster all i have is just Penryn-based systems, EVC cluster still applies the Merom-based baseline instruction set. I was wondering if it is possible to change this baseline configuration to Penryn-based so that applications running in my VMs on the host can take advantage of the new instructions in Penryn-based servers.

Regards,

Sudhir

[lamw]

Well since you can add both type of servers to a single EVC cluster, that means that it'll auto-configure as long as they can be configured to be compatiable with each other. The baseline is just whatever is in the cluster that it can auto-configure to get VMotion between new generation CPU's to older generation CPU's. So if you have a cluster of all "merom" and you add 1 new "peryn" type, then if it "can" be configured in the EVC cluster, than the new baseline will include both CPU types. EVC just auto-configures VMotion between different CPU generations so that a Admin does not need to configure every newly created VM with cpuid masking to ensure VMotion compatiablity, so if you can add a host to an existing EVC cluster that has a different CPU generation and it allows you to, then the baseline is modified each time. So to answer your question, it's a yes and with the new generations of CPU's, both AMD and INTEL are aware of these issues and try to create CPUs that are compatiable with VMotion.

[ssbangal]

BTW, do you mean to say if I have just the Penryn-based systems in my EVC cluster, the cluster automatically configures itself to use the additional instructions in the system that were not there in the previous generation of Merom-based system?

I am attaching a screenshot in which a EVC cluster is configured to just have one Penryn-based host. But if you see the message it still says "Merom" based systems? Is it just the message that is being displayed is wrong here?

Regards,

Sudhir

[prashantprahlad]

ESX 3.5U2 has one default baseline (Merom). You can use SSE4.1 if you create a new cluster with Penryns and don't enable EVC on it.

[prashantprahlad]

No, Your Penryn will become a Merom (i.e SSE4.1 is disabled) inside this EVC cluster. Are you using applications that require SSE4.1?

[ssbangal]

Thanks for the clarification Prashant. No, we are not using any applications that require SSE4.1 at this point of time. But I wanted to get clarification on the baseline instruction set.

Regards,

Sudhir