Here’s a real head-scratcher. Benchmarking site HWBot will no longer take results from Win8 machines, and has scrubbed its records of all existing Win8 results. Here’s why:
Unfortunately, though, Windows 8′s RTC [Real Time Clock] isn’t reliable. According to HWBot, Microsoft made some changes to Windows 8′s timekeeping routines to allow for low-cost devices and embedded systems that don’t always have a conventional PC-compatible RTC. HWBot doesn’t give specific details (presumably we’re talking really low-level kernel stuff here), but it proves its point with some damning empirical evidence. Basically, if you change your CPU base clock (BCLK) frequency in software (not at boot time), it has a massive impact on Windows 8′s ability to keep accurate time. By underclocking the BLCK of a Haswell system from 130MHz to 122MHz (-6%), Windows 8 loses 18 seconds over a five minute period (see video above); and the inverse applies to overclocking, too.
I’m guessing there’s nothing malicious going on, just a bad first-time software solution for a problem that previously was dealt with via hardware. Still, you have to wonder if some embedded systems that require strict timing functions might be adversely effected.
(Hat tip, Jim’s beard.)