That has nothing at all to do with power savings. Turbo boost means it kicks up a processor FIRST before it spawns another processor. My guess would be that the C1E p-state is not active here, which required for Turbo Boost to work.ĭear VMWare team, would you please remove the Xeon 元426 CPU from HCL? ESXi lacks support for the most interesting features of this CPU - power saving and Turbo Boost. In my opinion, there is only one conclusion left after these results: Turbo boost is not working under ESXi. In contrast to the Linux scenario where the power consumption saturates with two active processes due to Turbo Boost, we need four active processes here to drive the processor to its thermal limit. Unfortunately, i7z does not work in a VM, so I can't give any freqencies here.Īs you can see, the power behavior is totally different. The VM was configured to no CPU ressource limit. The results differ only after the decimal point). Under ESXi I did the same test, using one VM with 4 assigned CPUs (before you protest: I cross-checked 4 VMs using one CPU core each. Lauching further processes does not increase the power conumption anymore, but redistributes the availabe thermal budget between more cores. So even two processes get the CPU to that limit. These results show very well how Turbo Boost works: as long as there are idle cores, the busy ones are overclocked up to the thermal budget of the whole processor. Three processes: 56.2W, max frequency 2130 MHzįor processes: 61.1W, max frequency 2000 MHz

Two processes: 61W, max freqency 2800 MHz One dd process: 50.6W, max freqency 3200MHz

The true core frequencies were monitored using the i7z utility. Using one to four of these processes, I measured the power input of the whole system. Taskset -c 0|1|2|3 dd if=/dev/urandom of=/dev/null &

Esxi how to enable turbo boost