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#151 HawkMan


    Neowinian Senior

  • Tech Issues Solved: 5
  • Joined: 31-August 04
  • Location: Norway
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Posted 04 June 2014 - 15:59

No, that's not how it works.

This has very little actual performance effect, it affects at best weird case performance scenarios on a micro scale.

#152 OP hardbag



  • Joined: 22-September 01

Posted 04 August 2014 - 18:05


HardBag (or anyone else here),


How do I check the BCD on what's the current setting of useplatformclock, before making any changes to the BCD?


BTW, I have checked my system to see if Invariant TSC is supported or not. Says it's supported.

So does that mean I don't need to edit my BCD?


For those who don't know how to check, here's how:


1. Open AIDA64 -> Motherboard -> CPUID
2. Look for the field "Invariant Time Stamp Counter", and check whether it's supported or not.



Recently I've been doing around this issue as well, as my CPU supports invariant tsc too. Core i5 3570K


I'm not clear hot be sure that invariant tsc get's used - I'm not sure. There is motherboard too.. Usually with HPET setting.


I have removed use platforclock, and disabled HPET in bios. My DPC latency is low, but there's spikes. And these spikes we should be benching.. for example.


I though that that might give headroom for CPU to use Invariant TSC through the system and sync with OS... Maybe. I think I'm gonna re-enable the setting in motherboard, so that MB doesn't restrict hpet being used, as I assume the setting shouldn't block Invariant TSC .... I guess.


Fortunately I have to say that useplatformclock defaults windows to the best that the clock has (cpu), but is it so with mb's?


I would not perhaps reckon to use platformclock true unless one knows HPET is the best that the cpu can do, and to my assumption lot's does have!


Although looking at this topic I would say it's 50/50 if they benefited from use platformclock true setting.

#153 +dsbig


    Genx Security.

  • Joined: 09-April 09
  • Location: in your house eating your tuna

Posted 07 August 2014 - 07:40

turbo boost on cpu also causes latency spikes along speed step and other energy setting in bios.



I tested this and its true.


latencymon show low latency and hardly any spikes.


only drawback is that the cpu runs at 100% all the time.

#154 OP hardbag



  • Joined: 22-September 01

Posted 11 August 2014 - 03:40

I have turbo boost on all my cores, 3.8Ghz from 3.4Ghz i5 3570K, though I still have option that when full cores not needed those will slow down to 1.6Ghz, I mean when in idle. 3.8Ghz is almost 4Ghz so I'm quite happy just with turbo boost. Don't need other OC'ing for CPU.


When I disabled HPET on BIOS I couldn't have HPET on Windows (7 Pro x64), it didn't show up as system device in device manager, so I enabled it in BIOS and there it was again. As my CPU supports Invariant TSC I don't have useplatformclock set true. Although I dunno if Win 7 supports Invariant TSC. What I heard Win 8 defaults to it.


To sum up this topic, forcing platformclock true can be beneficial for half of the people, depending on hardware. But I guess "HPET tweak" can be called as Vista era tweak.


Anyhow here's a link to sum up http://www.tweakhoun...ks-benchmarked/


I think I'll default to baseline. But as this thread has shown some people do get benefits for setting use platformclock true.




From my part I'll draw this discussion to an end. However maybe there should be a timers discussion, so that people would be more in the know of what in where etc... As some people are very interested of these kind of stuff.



#155 OP hardbag



  • Joined: 22-September 01

Posted 12 August 2014 - 02:55

Please read this article




It might be that forcing platrformclock true might be the best after all, but different apps sets the timer, for example Chrome, how they want ~ so the user sure would get security of having the best timer with useplatformclock true...


Definitely on Neowin there should be a windows timers discussion, otherwise we're just n00bs.

#156 Jonathan Bennett

Jonathan Bennett

    Resident One Post Wonder

  • Joined: 20-October 14

Posted 20 October 2014 - 12:28

Well, this is awkward, but hello everyone. I have a question, when I enable HPET in BIOS it also enables a new option called HPET Memory Address, by default the value is FED00000h, but there are these other values: FED1000h, FED2000h and FED3000h, so should I change something here or leave it on default? If anyone is still around, please answer. Thanks in advanced.

#157 6H057D09


    Resident One Post Wonder

  • Joined: 31-December 14

Posted 31 December 2014 - 21:20

Hello, I have enabled HPET in device manager, I used the bcdedit useplatform clock command in administrator mode, and I enabled HPET in bios. 


However, in the wintimertester program, my ratio only gets to .9999 not 1.0, I am not overclocked. The frequency is 14.x though. Also, with windows set timer resolution program the program that maximizes timer resolution when HPET is enabled my highest resolution is 0.500 miliseconds.


But when HPET is completely disabled in everything including the platform clock (bcdedit not use HPET) In the windows timer resolution program my highest resolution is 0.488 miliseconds. Also, in wintimertester my frequency will be 4.1 and also gets to 1.0 ratio around 50 seconds.


So would I benefit from completely disabling HPET in my case? Is the 0.488 ms resolution, 4.1 frequency and 1.0 ratio better than the .500 ms resoultion 14.x frequnecy and .999 ratio with HPET enabled?

#158 WalterWKrijthe


    Resident One Post Wonder

  • Joined: 09-February 15

Posted 09 February 2015 - 14:42

A bit of a long stretch since this thread was started, but it's the first time I looked into HPET and other settings on my PC. I've got Windows 8.1 installed and used the instructions provided in this thread, and even though I haven't yet tested it in games, the results are as suggested:


QPF without: 2.61064

QPF with: 14.31818


Incouraging: MS Word started up way faster...


Thnx for the info and very clear instructions!