Quote:
Originally Posted by
MonarchX 
Well, I figured it was relevant because when HPET is enabled in BIOS, Windows 7 and Windows 8.1 enable it in themselves during clean install. Windows 10, however, does not enable it even when HPET is turned on in BIOS. Then I noticed latencies are much lower in Windows 10 than in Windows 8.1., using the same exact drivers. I thought that could be due to Windows 10 NOT using HPET. Since HPET is not used and latencies are so much better, it probably makes sense to disable HPET completely in BIOS, but makes way more sense not to also force it in Windows 10 itself because it is possible to do so with the same platform clock command as in Windows 7/8.1.
AFAIK, Windows 8.1 and now Windows 10 use CPU's TSC instead of HPET, which is a more modern and optimized method of controlling timings.
Yes, the OS uses TSC on most modern systems, but it WILL enable HPET if a specific program is written to use it, regardless of the HPET BIOS setting. That's why most X99 boards got rid of the HPET settings option.
As for the "software driver", eventually the OS WILL install the HPET driver when a piece of software activates the timer. (Again, regardless of your BIOS setting).
Not everyone will see higher latency when HPET in enabled in the BIOS initially. It's system hardware and software configuration dependant.
Also, the OP seems to contradict itself in various ways.
Point
Quote:
Windows 10 - disable HPET before install and enjoy low latencies
Contradiction
Quote:
advice to disable HPET because even if you have it enabled in BIOS, Windows 10 won't use it by default
Point
Quote:
it will install the system device driver for it
Contradiction
Also, just to point out another point you made:
Quote:
Windows 10 finally switched to some other (new?) method of handling latencies
It uses the TSC and/or TSC + LAPICs combo depending on your hardware and software configuration. Just as Win 7 / 8 / 8.1 did.
The issue is that you are forming a global view based on your isolated case, and have concluded this to be the truth behind OS and timers. Just to back up this point, here is another guy proclaiming absolute truth, but his point in the exact opposite to yours!
Quote:
By default Windows 7 uses different timers in the CPU to calculate stuff. HPET is the newest and best of these timers, but because of default combination of timers it takes longer time for CPU to keep up all the timers and sync between them. Forcing Windows to use HPET only improves performance and leads to greater FPS.
Steps to enable this tweak:
1. Enable HPET in BIOS. If you have HPET option in BIOS then your hardware can support HPET.
2. Enable HPET in Windows by giving this command in admin credential CMD:
bcdedit /set useplatformclock true
3. Reboot
Source:
http://www.neowin.net/forum/topic/1075781-tweak-enable-hpet-in-bios-and-os-for-better-performance-and-fps/
Sure, he's talking about Win 7, but I've clearly made the point that OS has less to do with the timer and more to do with hardware and the executed applications.
Edited by BradleyW - 8/3/15 at 8:28am
