Core I7 2600k + Asus P8P67 Deluxe - Fluctuationg BCLK?

[T101]

I ordered my parts on launch day, and I built the system this tuesday. It is running fine. However, I have noticed that the BCLK tends to fluctuate between 100 and 105Mhz. Since I have read about this platform being very sensitive to changes in BCLK it has me somewhat confused to why it keeps doing that. The CPU runs at between 1605Mhz and 3701Mhz (not reaching the 3800Mhz turbo frequency).

I am just putting it out here to get some feedback and food for thought on this as I continue to tweak the settings of the board, trying it out.

 

[Edrick]

Do you have the BCLK set to Auto or set to 100?

If Auto, I would try putting a 100 value in there.

 

[T101]

If I set it manually to 100, it fluctuates between 100 and 105. If I have it on auto, it goes between 100.3 and 101.3. I am on UEFI version 1053, btw.

 

[Arkainium]

Is your TPU enabled by any chance? I think it changes settings on the fly in an attempt to optimize performance.

 

[T101]

Yes. I think my TPU is enabled. I will try disabling it.

 

[T101]

It turns out the TPU switch is disabled by default. I dont know if you can change it in the AI suite software. I am still learning the functions of this software. I have not touched the switch though, so I hope it is off.

 

[Arkainium]

I think the only way to activate it via the AI suite is through the Auto Tuning tab in TurboV EVO. I haven't used that part of the software, so I don't know whether the hardware TPU switch needs to be activated beforehand. I did try enabling the switch once myself just to see what it does, and I immediately noticed that it adjusted my BCLK. That's when I turned it off.

If it's not the TPU, then I have no clue why your BCLK is fluctuating like that especially since you manually set it to 100. Pretty weird.

 

[T101]

I tried the autotuning, so I think the TPU is activated. I need to turn it on and then turn it off on the switch, if I remember the manual correctly, it will use software or switch, whatever was used last.

 

[T101]

For some reason, if I let the memory run on the default 1333Mhz, it seems that BCLK remains stable. But if I set the memory to its 1600Mhz as per its rating, the BCLK starts acting up. Firmware bug?

Granted, 5% variation is not much. I am just curious to why it behaves the way it does.

 

[T101]

To show how it behaves, I recorded AI Suite while watching a video. I hope it is ok to post youtube videos here.

http://www.youtube.com/watch?v=TxJPRdOWscM

I have cleared cmos, went through the settings again. Nothing can make that BCLK stable. It always varies like shown in the video. Any suggestions? Is this normal behavior? The other system I put together with identical component only varies between 99.9 and 100.3Mhz on the BCLK.

 

[bankster55]

try the beta bios
might also be throttling effects

 

[T101]

Throttling would be my guess. I am using the Beta 1053 bios.

 

[bankster55]

try disable EIST or EPU Power Save mode
its not a "bug" its doing something its supposed to do

 

[T101]

I will try disabling EIST and I dont think I have EPU enabled. I will check. I just tried something; I downgraded to the last official version of the bios (which does not support PLL overvolting on D2 revision cpus). And now the fluctuations are much less, only 1 Mhz. So something is different in that beta bios. I never had any problems running any of asus beta bioses in the past, but I guess there is a first time for everything.

I will try disabling EIST and EPU and then we will see if I can have it running without fluctuations (not that it matters, I am just curious to find the reason why it changes constantly, when the BCLK is supposed to be a fixed frequency). Might be throttling. We will see

 

[T101]

EPU disabled, EIST disabled. Still fluctuates. If this had been an old FSB type of bus, then I would not be concerned. But considering everything runs of this clock, I think it should be more stable.

 

[bankster55]

I am at a bit of a disadvantage here as I was waiting to find a SB vendor that didnt charge tax in my state (10%) and now i have found one, so it wont be but a few more days.

Might wanna look at these
http://www.youtube.com/watch?v=3vBN-cBPs98
http://www.youtube.com/watch?v=lajZi-JAFXA

If you want a definitive answer to your ques, register here and ask in Intel forum
These guys know everything
http://www.xtremesystems.org/forums/showthread.php?t=264874
http://www.xtremesystems.org/forums/showthread.php?t=265055
http://www.xtremesystems.org/forums/showthread.php?t=265050
http://www.xtremesystems.org/forums/showthread.php?t=264976

 

[T101]

Thank you Bankster55

Since I have spent the last two weeks with a cold and fever, I have done nothing but watch every video I can about sandy bridge, and reading up on what I need to learn. Still in the process of learning about this new platform.

I also hang around reading on that forum the last days. I will register and ask about it. *prepares to be branded a noob*