Optimal number of virtual CPUs, cores, and threads

[Patrick_3000]

I have SCALE installed on the following physical hardware: AMD Ryzen 7 Pro 5750G with 128 GB ECC memory. Therefore, I have one physical CPU, with 8 physical cores and 16 physical threads. I have an all-SSD pool (NVME) for VMs, with my datasets on a separate HDD pool.

I have two VMs: one Linux Mint and the other Windows 10.

What I'm wondering is the optimal number of virtual CPUs, cores, and threads. Currently, for each VM, I have specified 2 CPUs, 2 cores, and 2 threads, with host passthrough. Everything seems to work, but I'm wondering if this is the optimal setup. I actually don't understand what the correlation is, if any, between virtual and physical CPUs, cores, and threads. If anyone has any insights or suggestions, I'd appreciate hearing them.

 

[sfatula]

Virtual CPU x cores x threads = how many physical threads you are allocating. Optimal? Depends on what you need to accomplish with the VM and how fast you want it. It could be a low number of a high number.

 

[Patrick_3000]

Virtual CPU x cores x threads = how many physical threads you are allocating. Optimal? Depends on what you need to accomplish with the VM and how fast you want it. It could be a low number of a high number.

Thanks. Now I understand what they mean, so I'll figure it out based on what I'm using the VMs for.

 

[Whattteva]

90% of people only needs 1 or 2 cores/threads (I usually just do 2 cores x1 thread). I'd recommend to start from there and add more as you need. Allocating too many cores/threads can actually result in very slow performance.