Another look at HPET High Precision Event Timer

really? very interesting I wonder why?

 

because its a platform clock and the pch is a platform hub

 

tru , i wonder if ryzen chips have it onboard, since the server "eypc" chips dont need a pch at all.

 

theres a strong possibility of that, the ryzen io die is a reconfigured x570

 

Regarding the pre-set "Adaptive" power plan on some Windows .exe: I think they simply forgot to change it, as those were set in the profiles already, before optimal had been released.

 

No, as I suspected, it keeps using HPET. (Yes, I rebooted after disabling the device because I applied the boot parameter changes at the same time.)

 

ah, thats with hpet enabled in bios but disabled in os (i misread)

yeah, as i thought, the device manager device doesn't do anything.

So all the posts online about it doing so are purely placebo.

 

I've found the fix to my stuttering in COD MW 2019 it was the HPET.

https://forums.guru3d.com/threads/i...ryzen-latency-help.422352/page-3#post-5753423

 

What if you went full stupid by actually following the "advice" of experts that don't know anything and you started to change the settings of HPET via CMD, just like I did? Lol. How would you set that to "default" to just let Windows do its thing when it comes to all of these "tweaks" that honestly have not helped me one bit.

Is there a cmd command prompt to just revert all of these settings back to default or as if Windows had them the moment you reinstall it?

 

bcdedit /deletevalue XXX
https://docs.microsoft.com/en-us/windows-hardware/drivers/devtest/bcdedit--deletevalue

 

Sorry for spamming again, so I used "bcdedit /deletevalue useplatformclock", rebooted, then I used bcdedit /enum to check what has been changed and if anything needs to be reverted back to stock and useplatformclock does not appear anymore in there, it did appear when I tried to force it ON or OFF. With my Windows version, HPET is not enabled by default it seems like, as QueryPerformanceFrequency shows a small 3 MHz value. Everything feels ok and HPET apparently is at normal settting, isn't it? So if any app or program needs it, it will use it. I want it to stay that way.

Is this correct? Thanks!

 

Yeah. Deleting the setting you let Windows to decide.

PS On modern platforms Windows 7, 8, 10 does not enable HPET by default. It is just that Windows 10 latest builds started to use some synthetic timers/counters instead of pure TSC - hence the 10Mhz instead of 3.smthMHz for QueryPerformanceFrequency function.

 

I can tell you so much. My system (9900K on GB Aorus Master) becomes more or less unusable when the HPET is enforced. This should not happen, but still does. Windows desktop experience feels as if I downclocked the CPU permanently and when Stardock Fences is running that experienced slows down even further as if I was running on a downclocked Atom CPU.

Disabling various processes and services, as well as the NVidia driver and Intel LAN + WIFI driver made no difference. HPET on my system is broken. Whom do I blame, though, GB or Intel? No idea.

Fortunately the invariant TSC on my 9900K runs at 10 MHz, which should be sufficient for most tasks.

 

it happens because skylake and later significantly increased HPET readback latency.

https://www.overclockers.at/articles/the-hpet-bug-what-it-is-and-what-it-isnt

 

Yes, I know, but there is a difference between getting fewer fps in a game and turning the whole computer experience into molasse.

 

No, the TSC always runs at the stock base core clock frequency (doesn't follow neither SpeedStep/SpeedShift, nor TurboBoost), the Windows timer frequency is always lower. It used to be /1000, now it's always 10MHz (probably still divided from the TSC clock but I am not sure).

 

As far as I understand invariant TSC runs at the "nominal" CPU frequency, regardless of Turbo or P-state bins.

 

Why is this still being debated? Neither Windows or Linux choose HPET as platform clock, for good apparent reasons. HPET even got completely blacklisted for Coffee Lake on Linux. Every claim it to be useful in any way with non-ancient CPUs has never been backed, afaict. So please let this disgusting cruft just vanish from our collective memory, ok...?

 

Not everyone is just gaming, though, so higher precision time-stamps can be useful. Audio software used QPC for as long as it exists, when games likely did not even care. But since HPET takes too long to be queried it more or less remains only theoretically useful. Too bad.

 

AMEN!