alexnik108
Contributor
Contributor

Incorrect frequency 2xXEON + HT enabled + Turbo enabled

Hi,

I have ESXI 6.5 running on 2x E5-2650v4 (base frequency 2.20 GHZ, turbo frequency 2.90 GHZ, 12 cores) with enabled Hypertrading and Turbo Boost.

ESXI reports capacity 52.7 GHz.

With HT enabled I have 48 cores in total.

But can't understand why I have 52.7 GHz only. If should be 2.90ghz * 48 cores = 139.20 Ghz.

If I run Linux with kernel 4+, using cpufreq util I can get 48 cores all running at 2.90 Ghz.

What am I missing ?

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11 Replies
vijayrana968
Virtuoso
Virtuoso

52.7 GHz should be sum of one physical CPU with its total cores, can you check what its showing under host > configuration > processors

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alexnik108
Contributor
Contributor

Yes, but what about HT and turbo boost?

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vijayrana968
Virtuoso
Virtuoso

That's what I am saying to check in configuration to see what's its showing for total cores and hyper-threading.

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alexnik108
Contributor
Contributor

Hi,

have you read initial topic ?

"I have ESXI 6.5 running on 2x E5-2650v4 (base frequency 2.20 GHZ, turbo frequency 2.90 GHZ, 12 cores) with enabled Hypertrading and Turbo Boost.

ESXI reports capacity 52.7 GHz.

With HT enabled I have 48 cores in total.

But can't understand why I have 52.7 GHz only. If should be 2.90ghz * 48 cores = 139.20 Ghz.

If I run Linux with kernel 4+, using cpufreq util I can get 48 cores all running at 2.90 Ghz."

HT is enabled.

Total cores shows: 52.7 GHz and the question is why 52.7 Ghz and not 139.20 Ghz.

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vijayrana968
Virtuoso
Virtuoso

I read it, just wanted to check if you have confirmed these things there. How many CPU license are in use for this ? What is the edition in use.

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vijayrana968
Virtuoso
Virtuoso

License is entitled per CPU so make sure you are using correctly.

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bluefirestorm
Champion
Champion

The total capacity formula looks like is

number of sockets x cores per socket x base clock frequency

If your concern is whether Turbo mode is recognised or hyperthreading is recognised, you should look at the vmkernel.log

These are some lines that I see from vmkernel.log that may be relevant to your question. So you should also look for similar lines in the vmkernel.log of your ESXi host. As you can see from my sample below the calculated clock speed is not exact as well. This is an i7 with base clock frequency of 2.2GHz with hyperthreading. When the ESXi starts booting, I can see logs for cpu0 through cpu7 (quadcore with hyperthreading) and reported capacity is 8.8GHz (1 socket x 4 cores x 2.2GHz base clock)

TSC: 153560 cpu0:1)BootConfig: 190: hyperthreading = TRUE

TSC: 305186 cpu0:1)BootConfig: 454: disableTurbo = FALSE

TSC: 4579114210 cpu0:1)Timer: 734: cpu 0: early measured tsc speed is 2194917179 Hz

0:00:00:00.026 cpu0:1)SMP: 460: hyperthreading enabled

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vijayrana968
Virtuoso
Virtuoso

Seems like one license in use. 2 licenses will be require.

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alexnik108
Contributor
Contributor

Dear bluefirestorm,

cat vmkernel.log | grep -e Turbo -e hypert

TSC: 397489 cpu0:1)BootConfig: 190: hyperthreading = TRUE

TSC: 796473 cpu0:1)BootConfig: 454: disableTurbo = FALSE

0:00:00:00.000 cpu0:1)CPUIntel: 1065: Turbo Mode enabled by the BIOS

0:00:00:00.043 cpu0:1)SMP: 460: hyperthreading enabled

both are enabled,

but have no idea why only info regarding cpu0, as it has 2x CPU and license for 2x CPU.

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bluefirestorm
Champion
Champion

Try

cat vmkernel.log | grep Kick

You should very likely see up to PCPU 47

cat vmkernel.log | grep Topology

You should very likely see mapping up to 47

Maybe you should also try

cat vmkernel.log | grep cpu47

But you may not get any results as it may not use all the available CPUs during boot up of the ESXi hypervisor. Sometimes the log just say cpu0 or cpun where n is a number because it is using that cpun for that task. It doesn't mean it only sees one CPU.

I can say that the formula indeed is number of sockets x core per sockets x base clock frequency. On the quad-core HT-enabled i7 that I have, its reported capacity is 8.8GHz (1 x 4 x 2.2) but see PCPU 7 and CPU topology mapping up to 7.

In your case it is 2 x 12 x 2.2 = 52.8GHz but it is reported as 52.7GHz because if you search for measured clock speed it is not exactly 2.20GHz that would account for 0.1GHz difference.

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ASavener2
Enthusiast
Enthusiast

ESXi is showing the correct capacity.

24 physical cores * 2.2 Ghz = 52.8 Ghz.

Enabling hyperthreading will make the box show twice as many cores, but the total capacity of the CPU will remain the same.  (Hyperthreading can allow more efficient scheduling of the CPU cores, but the total number of physical cores remains the same.)

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