CPU Calclation

[souledgee]

Hi,

If I need to create multiple virtual machines, do I need to calculate the server CPU by cores or threads?

for example, I have a server with 1 CPU / 28 cores/56T, and I need to create 4VM with 15Vcpu,

should I calculate it based on core or threads?

BR.

[CallistoJag]

Depends on how high CPU use is on those machines, but normally should be fine to base it on threads. 

[souledgee]

thanks, but is there an option should i choose when I create vm, there are just 2 fields when i create the VM on exsi (Number of processors and number of core per processor) so I am confused about how to choose threads.

[CallistoJag · Accepted solution]

I would recommend normally setting number of cores in a vm, the processor option is there for OS and software licensing requirements where they are sometimes based on sockets machines have. Threads is not relevant, as ESXi treats threads like cores from this respect.

[souledgee]

in my case, i have 1 server with 1socket, 12core/24T, and i need to create 9vms (2vms with 16Vcpus and 7vms with 8vcpus), is that ok? or should i replace it with 2 socket

[CallistoJag]

So if I read this right, you have 1 server with 24T and you want to run 88vCPU? I would suggest at least 2 sockets, but 48T is still al little low for that much vCPU if these machines are likely to use a lot of that CPU. If they are mostly idle sure it will be fine.

[souledgee]

Thanks for your help its very helpful 

[ph1819]

Memory is where you need to make sure you have enough.  Most VMs do not require lots of CPU.  

[souledgee]

Calculating the CPU that I need, it's about 268 cores. If I calculate the CPU per core, it's not enough, but if I compare it to threads, it's more than enough,
This is why I need to know if I can use threads instead of cores in my project

[ph1819]

What is your workload?  Memory is more important than cpu in most circumstances.

[souledgee]

you are right, my workload is about 2178G, and the current ram i have is about  3072G