You were right.
Tech support advised to temporarily disable "Avast HW virtualization" in the settings. Without this option HWiNFO was able to display the effective clock.
Yeah, looks like it's Avast.
I tried disabling its screens first and adding HWiNFO to trusted apps, but that didn't help.
Then I uninstalled Avast completely. After that HWiNFO started showing the effective clock parameter correctly.
I will write to Avast tech support to get them to help...
I checked two other computers.
1) i5-12400, Windows 10 22H2 19045.3448.
2) i5-3550, Windows 10 22H2 19045.3324.
Both have HWiNFO v7.68-5300 installed. Antivirus is also avast free antivirus.
On i5-12400 also no effective clock is shown. But on the old i5-3550 everything works.
Changing the...
Hmm, that's odd. I'm using Avast Free Antivirus. Or when using a third-party antivirus, can Windows Defender still have some influence?
Windows 11 Pro, 22H2, 22621.2861.
I attach a debug file while running the CPU test in OCCT.