HPET and latencymon/DPC weirdness

Rofflay · 4 Feb 2013 at 15:34

Does anyone take this seriously and has the same issue? I ran DPC for a long time with hpet off and it seemed fine with around 7us idle and 45us watching vlc and gaming but when i ran latencymon i had kernel times reading 900us.

all my other latencies seemed fine apart from this kernel time under latencymon so i scoured around and decided to keep HPET on in bios and windows.Low and behold kernel times down to 12us and 3us idle all other latencies are the same.

So i run DPC again and idle us goes from 7us to 40us and vlc and gaming are showing around 60-70us.So is there a conflict under windows 7 or which one is right? Im going to debug a bit more later on and see if i have more mouselag or microstutter but i must admit this one has me stumped.

wintimer reports HPET with 14mhz timer etc so i know im using HPET.

Rofflay · 8 Feb 2013 at 09:59

update seems it fixed with new version of latency mon 5.0

shankly1985 · 8 Feb 2013 at 10:09

I used to ues HPET under Windows 7. But on Windows 8 I had loads issues with sound stuttering and frame drops on BF3.
Switching HPET off in BIOS and Windows fixed it for me I still get odd spikes on USB but I think this down to me using Windows 7 drivers for my Corsair headset they releasing Windows 8 drivers soon.

Rofflay · 8 Feb 2013 at 13:03

Well i will check it out tomorrow maybe but i thought i only noticed slightly higher latency maybe an extra 20us but ill swear it was less smooth with HPET on.People elsewhere claim HPET on in bios and windows offers better fps in say world of warcraft but again i noticed nothing in battlefield 3.

If you use wintimer it should read 14mhz for full bios and windows HPET under windows 8 and there is another command called tickrate or something that might be in the below topic.I dont think it should cause sound stuttering though but its a bitch to diagnose as none of the latency counters like mon or dpc can read windows 8 latency correctly yet.Windows 8 HPET is a confusing mess compared to the off/on of windows 7.

http://www.neowin.net/forum/topic/1...n-bios-and-os-for-better-performance-and-fps/