This
blog will help you to understands the difference between PCPUs, LCPUs, vCPUs.
When HT is not present or not enabled called A singled physical CPU core (PCPU)
When HT is present and Enabled called A single logical CPU core (LCPU)
When HT is not present or not enabled called A singled physical CPU core (PCPU)
When HT is present and Enabled called A single logical CPU core (LCPU)
As per VMware PCPU and LCPU both same.
Example 1:
If a host has two eight core processors and HT is not
present or not enabled, that host has 16 physical CPUs (8 Cores x 2 processors = 16 PCPUs)
Example 2:
If a host
has two eight cores and HT enabled, that host has 32 Logical CPUs.
(8 Cores x 2 processors x 2 threads per core = 32 LCPUs)
In virtual
machine, processors are referred to as virtual CPUs (vCPUs). When an administrator adds vCPUs to a virtual machine, each
of those vCPUs is assigned to pCPU and also actual pCPU may not always be the
same.
How to Calculate vCPUs:
For better virtual
machine performance (3: 1) or (5:1) = (3 vCPUs: 1 pCPU) or (5 vCPUs: 1
pCPU)
In vSphere 5.0, there is a
maximum of 25 vCPUs per physical core. It means the ratio is 25:1.
If the ratio (3 vCPUs per 1 pCPU)
From example
1: ESXi have 16 PCPUs, if the ratio
is 3:1; the total vCPUs is 16*3 = 48 vCPUs.
From example
2: ESXi have 32 LCPUs, if the ratio is 3:1; the
total vCPUs is 32*3 = 96 vCPUs.
If the ratio (5 vCPUs per 1 pCPU)
From example
1: ESXi have 16 PCPUs, if the ratio
is 5:1; the total vCPUs is 16*5 = 80 vCPUs.
From example
2: ESXi have 32 LCPUs, if the ratio is 5:1; the
total vCPUs is 32*5 = 160 vCPUs.
Note: In vSphere 5.0, there is a maximum of 25 vCPUs per
physical core and administrators can allocate up to 2,048 vCPUs to virtual
machines on a single host.
