Jump to content


  • Please log in to reply
157 replies to this topic

#46 Mark


    (: ollǝɥ

  • Joined: 22-October 04
  • Location: Derbyshire, UK

Posted 30 May 2012 - 07:56

I applied this a while ago. I just noticed over the past couple of days that I'm getting some occasional cursor lag, it'll just stick for like quarter of a second and then carry on as usual.

Did anyone else get this as an issue with changing the system timer?

#47 SkyDX


    Anime Computer Enthusiast^^

  • Joined: 22-March 09
  • Location: Europe^^

Posted 30 May 2012 - 10:31

Thanks for the tip though is it maybe a Intel only thing? I haven't looked in my BIOS yet but I'm on a GIGABYTE AM3+ board and the device manage lists no HPET device :pinch: (Or is it related to the fact that I still use a 32bit OS? :p)

EDIT: Looking through the online manual my GA-870A-UD3 seems to support HPET, I guess I will play around with it sometimes^^

#48 Reacon


    [VGW] Woohoo!

  • Joined: 12-May 08
  • Location: Katabatic
  • OS: Win 7 & Slackware

Posted 30 May 2012 - 19:29

My ratio takes a few minutes to settle at 1.000, should I be worrying about this?

I also discovered I had 32 bit HPET enabled in BIOS, and not in Windows. Since I already had it enabled, I guess I should see no difference going to 64 bit and enabling it in Windows except maybe a decrease in microstutters.

#49 Javik



  • Tech Issues Solved: 3
  • Joined: 21-May 12

Posted 30 May 2012 - 19:57

It seems as if this option was always on in my BIOS, but disabled in the OS. I enabled it and the WinTimer app reported my sync performance at 14.something MHZ, and whilst it appeared to have no real effect in gaming (my primary usage) it did seem to make my mouse notably more laggy. The BIOS I have only had options for "Enabled" and "Disabled" so I can't tell you whether it was 32 or 64 bit, and whether it was running in mixed mode but my performance seems best with it enabled in BIOS but disabled in OS. Setup is as follows:

i7-2700k overclocked to 4.8 GHZ (1.4v)
Asus ROG Maximus IV Extreme-Z Z68 Motherboard (Bios version 3304)
8GB Corsair Vengeance LP DDR3-1600
2GB ATI 6950 (Bios Modded to unlock the extra shaders)
OCZ Agility 3 60GB boot drive

#50 MythicaL



  • Joined: 09-June 07

Posted 10 June 2012 - 08:49

Latencies are about the same as before (according to that DPC Latency Checker tool). QueryPerformanceFrequency is now at 14.31818 MHz, but I don't really notice a difference in performance.

I'll have to give it more time and see what happens.

#51 OP hardbag



  • Joined: 22-September 01

Posted 19 July 2012 - 08:15

the effects are best seen in such applications as games, and especially online-connected games. You should be able to play with more graphics on, and suffer no micro-stuttering. However HPET tweak is highly hardware dependent and it cannot be predicted what's the outcome - by other means than testing.

Other thing, I heard MS is dropping LAPICs away from Win 8.

#52 HonoredShadow


    Resident One Post Wonder

  • Joined: 20-July 12

Posted 20 July 2012 - 11:02

Well I tried 'bcdedit /set useplatformclock true' but I think it made it worse.

How do I put this to what ever is Windows 7 default please?

#53 +Zlip792


    Neowinian Senior

  • Tech Issues Solved: 26
  • Joined: 31-October 10
  • Location: Pakistan
  • OS: Windows 8.1 Pro 64-bit
  • Phone: Nokia C3-00 (8.70 firmware)

Posted 21 July 2012 - 03:43

I got this while enabling in OS.. Enabled from BIOS..
Posted Image

#54 ahhell


    Neowinian Senior

  • Joined: 30-June 03
  • Location: Winnipeg - coldest place on Earth - yeah

Posted 21 July 2012 - 04:13

the effects are best seen in such applications as games, and especially online-connected games. You should be able to play with more graphics on, and suffer no micro-stuttering. However HPET tweak is highly hardware dependent and it cannot be predicted what's the outcome - by other means than testing.

Other thing, I heard MS is dropping LAPICs away from Win 8.

Are you really still trying to push this snake oil? Let it go, man.

#55 OP hardbag



  • Joined: 22-September 01

Posted 22 July 2012 - 16:47

Honored shadow, read this whole topic. I have provided the code to get back to "default".

Zlip792, run cmd with admin privileges.

ahhell, HPET tweak is a very good one for certain people. It doesn't work for everybody. And actually MS heavily pushed HPET timer in Vista, but stepped back Win 7. I don't know why. But the timers are changing again - in Win 8 at least LAPICs are dropped off.

#56 chaosinfected



  • Tech Issues Solved: 4
  • Joined: 11-October 03
  • OS: 10 x64

Posted 22 July 2012 - 16:57

Are you really still trying to push this snake oil? Let it go, man.

Doesn't look like snake oil to me.

#57 kalston


    Resident One Post Wonder

  • Joined: 07-August 12

Posted 07 August 2012 - 20:38

Now this is an interesting thread.

I've done the tweak and I can tell it's smoother (not really in terms of FPS but in terms of "felt" smoothness) however my mouse feels a lot different and it actually feels laggy, like with v-sync on at 60hz (not that bad actually but close). I don't understand why that is. It's like everything's delayed so as to be smoother (again, kind of like v-sync) and I didn't expect that from a "timer" tweak. My OS feels smoother but slower too (less responsive).

I haven't played with HPET off in ages though, might give it another shot (right now I'm just comparing HPET on in BIOS + not on in Windows and HPET on in BIOS + on in Windows).

#58 Brian Mitchell

Brian Mitchell

    Resident One Post Wonder

  • Joined: 18-October 12

Posted 18 October 2012 - 09:01


I have actually replaced a motherboard so i could disable HPET. Ignoring the fact that HPET does not affect FPS more than a couple FPS, and that difference is measured on some benchmark because when you are benchmarking YOU DONT TOUCH THE MOUSE BECAUSE IT WILL AFFECT THE SCORE, RIGHT? When you are actually in a game there is near constant input, right? (If there isnt then you are probably just camping the entire time and if so then I suggest simply hitting ALT-F5).
Input results in ISRs and DPCs regardless of how good your system is setup or how many FPS you get when you benchmark. HPET lengthens the execution time of those ISRs and DPCs, which results in input lag. If your FPS is too low and you lower your graphics settings the game may not look as pretty but you can still play effectively, but if your DPC Latency is too high, then you have to not only consider real world factors such as bullet drop, wind speed and direction, and target movement, but you also have to compensate for the DPC latency. Lowering your graphics settings wont help with that, trust me. Lowering the DPC Latency made a huge difference for me, at the time i was playing crysis wars on an i7 2600k running at 4.2Ghz with two 5870's at 1Ghz. My FPS never dropped below 120 and usually it was much higher, and lowering my DPC Latency from between 50-80 to close to zero made a huge difference in my hit ratio and my K/D.

Heres some text from Von Dach's post on GURU 3D:



Problems HPET is a continuously running timer that counts upward, not a one-shot device that counts down to zero, causes one interrupt and then stops. Since HPET compares the actual timer value and the programmed target value on equality rather than "greater or equal", interrupts can be missed if the target time has already passed when the comparator value is written into the chip's register. In the presence of non-maskable interrupts (such as System Management Interrupts) that don't have a hard upper bound on their execution time, this race condition requires time-consuming re-checks of the timer after setup and is hard to avoid completely. The difficulties are exacerbated if the comparator value is not synchronized with the timer immediately, but delayed by one or two ticks, as some chipsets do.

A guy on another forum claimed that by disabling it, his DPC latency plummeted and his gaming performance improved; most notably the microstuttering.

So I tried it myself, and the difference to my astonishment, was very noticeable. First off, my DPC latency dropped big time. Not that it was high to begin with, but now it hovers below 10 for the most part.

Second, I noticed that general windows performance felt snappier. I know I'm not imagining things, because like many, I scrutinize my system so I'm sensitive to even minute changes in performance.

And last but not least, gaming performance is definitely smoother. Anyone with SLi will tell you that occassionally when playing a game, you experience a bit of lag or stuttering for no apparent reason whatsoever. Most people attribute these minor discrepancies to SLi, but what if it's something else? Because I can tell you, that my overall gaming experience has improved since turning HPET off.

If you have the HPET option in your BIOS, I highly recommend experimenting with it and see if it impacts your performance. There's a possibility that having it on could increase the amount of microstuttering in any given game; particularly if you're running SLi.

It can be used by software or the os for very accurate timing, however when it's "ON/Enabled" then windows will use it as the main clock source instead of the other options like the cpu TSC (time stamp counter).

The HPET can provide more precise timing, however the OS has to reference it via a memory address, or I think the HPET can raise a interrupt,
so therefore it's slower.

The TSC may be less precise, however it's a register in the CPU so this is the fastest possible way to access a clock source.
My own result with DPC Latency Checker:

HPET 64-Bit ON: between 100-150us
HPET OFF: between 5-15us

I loss 3-4 frames per second, single card and CFX with HPET OFF, but I know chance of stuttering decreased accordingly.

*Some motherboards have HPET enforced and it can't be disabled (Asus).

Maximize your Windows timer resolution
Just keeping this little application open in the background will reduce DPC latency, improve responsiveness. Good workaround particularly for those who are stuck with an enforced HPET On.

I tested this on my workstation dual core who is using a lot of CPU time constantly. HPET is off.

DPC Latency is ~650us at 0.977ms timer resolution (default with my apps running).
DPC Latency is ~190us at 0.5ms timer resolution (maximized).

I now keep this app running constantly in the background, everything feel snappier.

On my gaming rig, HPET On (for this test purpose only):

DPC Latency is ~100us at 1ms timer resolution (default with DPC Latency Checker running, Windows default is normally 10ms)
DPC Latency is ~10us with some peak at 100us at 0.5ms timer resolution (maximized)

Entering a game normally bring timer to 1ms but you can improve it even more with this application running in background to 0.5ms. Depending the game and your system you may feel better responsiveness and less stuttering.

#59 sideskroll


    Resident One Post Wonder

  • Joined: 22-January 13

Posted 22 January 2013 - 10:53

Hi everyone. I just registered to this site cause I had to ask something.
On my PC, when I run WinTimerTester this is what I get:
Posted Image
Now, I just re-installed the OS, and I HAVE NOT messed with the command provided here. (nor has anyone else)
So what does that mean? (I just "discovered" this cause I was messing with my BIOS options, you know, to "squeeze" a little bit more of performance out of my machine) So reading about that option (HPET) led me to this discussion.
(By the way, it was enabled by default)
Thanks in advance.

#60 Cartel


    Resident One Post Wonder

  • Joined: 11-March 13
  • Location: BC, Canada

Posted 11 March 2013 - 10:20

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

I just registered to share my results.
Print Screen 2013092.jpg

Print Screen 2013094.jpg