Why does my host report wrong number of Processor Cores?

[kevinbirks]

Hi all, I'm very new to virtual technology and have purchased a Dell CS24-SC to play with. It has two Intel Xeon L5420 processors (quad core). My question is, why does the host only report that I have two processor sockets but only 1 Processor Cores per socket

[weinstein5]

Welcome to the Community - I would look at the system BIOS and make sure nothing is disabled - ESXi should read the number of cores and sockets presented by the BIOS and whether Hyperthreading is enabled which will effectively double the number of Logical CPUs

[rcporto]

Check this another thread: Re: ESX only sees 1 core per processor

[Ramesh Dhanaraj]

It's seems Hyperthreading is not enabled in the BOIS level as well OS level. make sure You have enabled esxi requirement and supports options are enabled such as 1) check whether the BIOS is set to enable all processor sockets and to enable all cores in every socket. Also, set “Turbo Boost” within the BIOS if your processors support it. 2) check that hyper-threading is enabled within the BIOS if supported. 3) NUMA-capable systems offer the possibility within the BIOS to deactivate NUMA by activating node Interleaving. According to ESXi best practices, it is best to leave NUMA enabled since you get the most effective performance by deactivating node interleaving( you can even disable) 4) Check that any hardware-assisted virtualization preferences (VT-x, AMD-V) are enabled in the BIOS. 5) set power management within the BIOS to “OS Controlled mode” it is not availableset to  High performance .