[torin3]

Going to work on the overclock on my EVGA E762 Classified board today. I've got an i7-920 in it, and I'm shooting for a 4.2Ghz minimum overclock.

I've got watercooling on the CPU and the motherboard (full coverage block).

I'll be popping back in from time to time and reporting on how I'm doing.

[torin3]

ARRGHH!!!

Ok, I'm having weird problems...

First off, I wasn't able to go from 150 Bclock to 160 Bclock using Miah's guide for Bloomfield when isolating the Bclock. Then for some reason, I was able to.

Got to 190 Bclock without too much issue after that. Then, going to 200 Bclock, I go down to 2 GB of RAM being recognized (in windows and BIOS). I swapped the RAM in the slots and reset the BIOS. Ok, I can boot, and I can see the full 6GB again. But when I try to return to 190 Bclock, I can't get there. I have to reset the BIOS each time I try to boot at 190. It doesn't even get to the BIOS beep before it locks up.

I've got no idea what is causing my problem.

Any suggestions?

[redduc900]

Change the MCH Strap from Auto to either 1600 or 1867, and bump VTT voltage to 1.25-1.30V.

[torin3]

Originally Posted by redduc900

Change the MCH Strap from Auto to either 1600 or 1867, and bump VTT voltage to 1.25-1.30V.

Tried, and no joy for either strap at 1.30V on VTT.

[redduc900]

As you're looking for the highest BCLK, what's the DRAM multiplier set to?

[torin3]

Originally Posted by redduc900

As you're looking for the highest BCLK, what's the DRAM multiplier set to?

2:6, the lowest it will go.

[redduc900]

Change the DRAM mult. from x6 to x8 = DDR3-1520 at 190 BCLK, this w/ the strap set to 1600, VTT set to 1.25-1.30V, and IOH voltage set to 1.15V. Once you hit a 200 BCLK, change the strap to 1867.

[torin3]

That seems to have gotten me back in the game. Booted up at 190 Bclock, at 15x multi.

However EVGA E-LEET shows my CPU VTT at 1.30 and 1.35 based off of where I'm looking at it (monitoring / voltages tabs). I've got it set to +100mv, and I believe its base voltage is 1.20V.

Going to run a quick burn test and then start working my way back up again.

Thanks! I didn't realize the memory multiplier might have been the problem.

[torin3]

Also looks like the CPU VTT start point isn't 1.2V. It may be 1.15V. I've got it set for +200mv and I'm reading it at 1.36 on my DMM.

[dejo]

the higher the cpu clocks the more vtt you will need even if mem is at the same setting.

[torin3]

Originally Posted by dejo

the higher the cpu clocks the more vtt you will need even if mem is at the same setting.

When should I start worrying on the vtt voltage? I'm at +250mv at 206 bclock. About every 2Mhz on the bclock seems to need a bump of +025mv on the vtt.

Also, I'm still on the 1600 strap. Every time I try and jump to the next strap it requires a CMOS reset.

[redduc900]

Changing from the 1600 to 1867 or higher strap shouldn't require a CMOS reset, at least one isn't required w/ the P55. Normally after changing the strap, then saving and exiting the BIOS, you'll get a double-POST instead of the standard single-POST because each of the dual clock generators needs to be re-synced.

[torin3]

Originally Posted by redduc900

Changing from the 1600 to 1867 or higher strap shouldn't require a CMOS reset, at least one isn't required w/ the P55. Normally after changing the strap, then saving and exiting the BIOS, you'll get a double-POST instead of the standard single-POST because each of the dual clock generators needs to be re-synced.

Something weird must be going on then. Because when I change to the 1867 strap, save the change and reboot, it never gets to the POST beep. The number LEDs for the debugger rotates through the same 4 numbers and it never gets past that. I even let it run for about 5 minutes in case I wasn't waiting long enough.

If I have recover OC turned on in the BIOS it will POSt, but it pops up saying it recovered in safe mode, and please reset the cpu/mem settings. The overclock settings are lost.

[redduc900]

Interesting... this w/ BIOS revision 77? If you already have the latest BIOS, then I would just leave it at 1600 for the time being, or even try the 2133 strap. There may be an issue w/ timing table 5, at least w/ older revisions, which is what the 1867 strap uses.

Edit: I just realized the reason the 1867 strap isn't working for you, and that's because of the low DRAM frequency. It's not until the DRAM freq. reaches DDR3-1867 that timing signals shift, so just leave the strap at 1600 for now. Also make sure the uncore is at x16 or x17 w/ the DRAM mult. at x8.

[torin3]

No, it is BIOS 74. Think it is worth it to flash it to the new revision?

Currenly, I'm running a longer Intel Burn Test at 200 bclock / 21x multi and then I'll call it a night if it is stable.

I've got the CPU VTT up to 1.50V at 212 bclock. Would you say that is too high?

My memory is rated at 1600, and I'm getting that at 200 bclock. I'd been at x20 on the uncore, because I wasn't quite clear on what the guide was asking for in that field. I've got it set to x17 now.

[redduc900]

I'd probably check the revision history, and see if there are any fixes that apply to your situation before flashing. And a VTT of 1.50V is a little excessive, not for a 212 BCLK, but just in general since Intel spec's 1.35V as the absolute max. for the i7-900 series.

[torin3]

Originally Posted by redduc900

I'd probably check the revision history, and see if there are any fixes that apply to your situation before flashing. And a VTT of 1.50V is a little excessive, not for a 212 BCLK, but just in general since Intel spec's 1.35V as the absolute max. for the i7-900 series.

According to several places I've checked, the Intel spec got upped to 1.4V (unless they are old and they dropped it back down again).

But yeah, I'm a little nervous about that. I'm wondering if the full coverage water block will make a difference. The temp for VREG in E-LEET monitoring was going up with the CPU VTT increases, and it maxed out at 37°C when the multi was down to 15x for the CPU.

Running Intel Burn Test, at 4.2Ghz, I'm getting about 54-62°C for the CPU cores.

EDIT: Passed about an hour of the burn test. Seeing if it is folding stable now. But yeah, 4.2Ghz!