How exactly to calculate vCPUs?

[anggapw]

From several articles I read

(number of cores x number of threads per core) x number of CPUs

But I also found different answers when asking some AI. For example Intel Xeon E-2288G (8 Cores/16 Threads)

According to ChatGPT: 8cores × 16threads per core × 1CPU=128vCPUs
According to Bard: 8 Cores * 2 Threads/Core = 16 vCPUs

Is hyper-threading capability also a consideration?

Which is the right formula? because I'm creating a home-lab server and considering buying a CPU between Intel i5 8500 and i7 8700 (support hyper-threading)

 

[Dunuin]

According to Bard: 8 Cores * 2 Threads/Core = 16 vCPUs

Thats the correct one. But keep in mind that 16 vCPUs wont get you 16 times the single core performance. While 2 threads per core might give you some better performance, only one task can be done at the time by the core while the other thread has to wait if the ressource is busy.
And don't assign all cores to the CPU. The PVE host also needs some ressources.
With that CPU I wouldn`t give a single VM more than 7 vCPUs.
And don't assign a VM more cores than it actually needs as this will unnecessarily increase queuing.