Plugging the drive where Windows 8 was installed to an AMD system seems to have fixed the issue on Intel platforms.
Exemple:
Install Windows 8 on Intel: affected
Plug the SSD to an AMD system: not affected
Plug it back to an Intel system: not affected


So I have to test AMD again with a fresh install.

AMD confirmed not affected.

Did a fresh install and benchmark results are ok and windows time is ok too.

Quote:

Very interesting finding!

AMD you drunk, fixing Intel problems and shit

Since going from an "AMD install" to an Intel system seems to fix the problem I think it's just Windows 8 that read by default the wrong timer on Intel systems. Easy to fix but to moderate (hwbot) ...

Fresh installed Windows 8 on AMD system isn't affected when moved to an Intel system.


LGA1366 affected too.

The only tests I see remaining to be done are: Fresh Windows 8 install on say Sandy Bridge and LGA775 to see if it's only when installing on Haswell then moving to other platforms that get them affected or if all Intel platforms are affected.

I think the following:
Windows 8 use the CPU internal timer (RDTSC) on Intel and on AMD it reads the external RTC.
Before, with Windows 7, Windows was reading/using the external RTC on both.

"We also received a couple of emails debating the topic of which is to blame, Windows 8 or Intel CPUs. Based on the information we gathered from clock drift problem on various operating systems and hardware platforms, we are still of the opinion that Windows 8 is the root cause of the problem. Windows 8 seems to be using a different source to fetch “real time” on an Intel based system compared to an AMD based system. It’s still guess why and which at the moment, but it seems to be related to the power saving features integrated in Windows 8. With Windows 7 unaffected, and Windows 8 affected on all Intel platforms (including old generations), the root of the problem lies with Windows 8. Having the Intel system unaffected when coming from and AMD Windows 8 installation indicates that the correct timers are available on Intel too, but unused by Windows 8."

http://hwbot.org/news/9824

Clocking in: Windows 8 RTC overclocking issues are blown way out of proportion

Franck D. from CPUID made me an app yesterday to measure the following timers: ACPI, HPET, RTC. So I installed again Windows 8 on my Haswell test setup and tested his app.
Following the results:

No BCLK change: (everything is normal)



BCLK change: 100 MHz to 97 MHz, after 243s you see the RTC Timer is 8s far



BCLK change: 100 MHz to 95 MHz, after 243s you see the RTC Timer is 13s away



BCLK change: 100 MHz to 102.5 MHz, after 245s you see the RTC Timer is 6s away

Sweet, that's looking interesting.