Hardcore PC owners like to use software such as Futuremark's 3DMark and PCMark in order to show how powerful their rigs are compared to others. One of the biggest benchmark communities is HWBOT, which collects scores from its members. After they are verified, the people who submitted the scores are awarded points on the site.
This past week, the HWBOT site posted up a article on its blog that announced that, from now on, they were banning any benchmark scores submitted from Windows 8 PCs. The blog puts the blame on the real time clock (RTC) in Windows 8. Besides just making sure that your PC has the correct time, benchmark software applications use the RTC as well. HWBOT says, "By synchronizing with the RTC, the benchmark knows exactly how much time has passed, and takes that value into account when calculating the performance of your system."
HWBOT says that Microsoft created Windows 8 to be compatible with as many devices as possible, but because of this effort, it had to make some changes to its RTC in how it measures time. The blog says those changes made Windows 8 " ... compatible with embedded or low cost PCs that do not have a fixed RTC clock."
However, the effects of those changes can also cause alterations in benchmarks. HWBOT says that if a PC user changes their CPU base clock (BCLK) frequency in software, it throws off the RTC in Windows 8. The chart above shows how benchmarks on their test system, running an Intel Haswell CPU, were affected by downclocking the chip.
The blog also posted two videos that showed the effects of underclocking and overclocking the CPU and how it affects the RTC in Windows 8.
As a result of these findings, HWBOT has decided to block any Windows 8-based benchmarks from being submitted to their database, "... even if the score seems in line with the expectations." We have emailed Microsoft to get their comments as well as Futuremark, who have released two benchmarking programs that support Windows 8 PCs.