Well AFAIK HPET was Microsofts baby and when Vista was launched it was the default for QPC, well it didn't even have a useplatformclock option to turn it off. Then W7 switched to TSC but at the time quite a few people were overclocking bclk through software with programs such as setFSB. That didn't play nice since Windows only did an initial frequency check so many of those guys went back to HPET. FWIW since I'm not an avid gamer then HPET works just fine for me even today. When I tried it only appears to check timer resolution once when the program itself is started so not very suitable. W7 and W10 seem to be quite different in how they handle timer resolution. When running unigene Heaven bench W7 appears to switch back and forth from 1ms to 10ms and has a much coarser granularity while W10 switches all over the place and will go down to 0.5ms without intervention or even lower if allowed but we wont talk about that Here's sampling 10x a second on W10 with useplatformtick yes/no. Might have to slow it down to see some of the changes.