Some cloudvirt machines have very slow CPU for example cloudvirt1004, cloudvirt1005, cloudvirt1012. They have some not so recent CPU but that itself does not really explains why they would be twice, if not three times slower in raw CPU power.
On investigating, that seems to affect HP Proliant machines and @hashar suspects that could be due to HP power management sytem see eg https://support.hpe.com/hpsc/doc/public/display?docId=emr_na-c03031625&docLocale=en_US
labtestvirt2003.codfw.wmnet is a test machine and it could be used to measure CPU performance. The tests to conduct would be to run the bash oneliner below directly on the machine, and eventually under KVM. Then check the HP Bios settings for power management, try a different profile and rerun the benchmark?
The server is a ProLiant DL360 Gen9 with Intel(R) Xeon(R) CPU E5-2650 v4 @ 2.20GHz.
Some tools @hashar used to run math on 1 thread, the first one should be sufficient
- time $(i=1; while (( i < 2000000 )); do (( i ++ )); done)
- sysbench --test=cpu run
- stress-ng --cpu 1 --cpu-ops=4000
That CPU is found on lot of MediaWiki application server. On mw1307.eqiad.wmnet the shell oneliner takes 7.5 - 8 seconds.