**Official** Core i7 860/870 overclocking thread

[Vinas]

The results that don't include at least 10 passes of linx are pretty much useless, unfortunately.

Even then the CPU may not be fully stable but I think that 10 passes is good enough for most people here. Anything below isn't stable in my experience. The chips do seem stable with lets say 5 passes, but they eventually error out.

[Raul-7]

The results that don't include at least 10 passes of linx are pretty much useless, unfortunately.

Even then the CPU may not be fully stable but I think that 10 passes is good enough for most people here. Anything below isn't stable in my experience. The chips do seem stable with lets say 5 passes, but they eventually error out.

Yes, I still don't feel that it's stable. But under LinX it reaches 85C within the first run. These Lynnfield chips really need WC.

[PolRoger]

Yes, I still don't feel that it's stable. But under LinX it reaches 85C within the first run. These Lynnfield chips really need WC.

I agree... these 1156 hyper-threaded chips can run very hot as the overclocks go up!

I picked up this i7 860 recently and this is the first overclock I've been testing... running gskill ram at ~ ddr3-2133. Vcore is set to ~1.33v in BIOS (without vdroop/LLC enabled) and the board overvolts to ~1.35v load.

[managerman]

Here is my first P55 build...



Still tweaking...the Corsair 8gb of memory is really giving me headaches...If I run it at 1600mhz 9-9-9-24, then the MB only sees 4GB instead of 8GB...If I run it at 1200 MHZ with 7-7-7-20 timings it sees all 8GB?? I think this is an EVGA issue...

[bot@xs]

what does the rest of your voltages look like?
a bit high on the vcore there for my taste

[SimpleTECH]

Still tweaking...the Corsair 8gb of memory is really giving me headaches...If I run it at 1600mhz 9-9-9-24, then the MB only sees 4GB instead of 8GB...If I run it at 1200 MHZ with 7-7-7-20 timings it sees all 8GB?? I think this is an EVGA issue...

Try increasing your VTT.

[Snowman89]

what does the rest of your voltages look like?
a bit high on the vcore there for my taste

How high vcore is okey on air and then on phase?

[bot@xs]

i try to stay under 1.45, 1.5 at max for benches only, no 24/7 run

[Snowman89]

i try to stay under 1.45, 1.5 at max for benches only, no 24/7 run

That for air or for phase? How much for 24/7 with highend air then?

[bot@xs]

for 24/7 i usually don't use more then 1.4v
1.3625v is intel spec max vcore, i would not want to go to much above that for 24/7 operation if the system is loaded for most of the time .. air or water.

[Raul-7]

for 24/7 i usually don't use more then 1.4v
1.3625v is intel spec max vcore, i would not want to go to much above that for 24/7 operation if the system is loaded for most of the time .. air or water.

1.45 is the Vmax for Vcore and 1.55 is the absolute Vmax.

[bot@xs]

i stand corrected, it's 1.4v
http://processorfinder.intel.com/det...x?sSpec=SLBJJ#

[unclewebb]

bot@xs: That's the maximum VID and not the maximum safe voltage.

[Simonzi]

Just finished putting my 860\Maximus III Formula together yesterday. Going to start the OC process tomorrow, will have results then

[bot@xs]

thanks uncleweb, i did not know and am glad you found this. i will apply some of this.
also interesting to note is PLL and VTT here

[-n7-]

Here is my first P55 build...



Still tweaking...the Corsair 8gb of memory is really giving me headaches...If I run it at 1600mhz 9-9-9-24, then the MB only sees 4GB instead of 8GB...If I run it at 1200 MHZ with 7-7-7-20 timings it sees all 8GB?? I think this is an EVGA issue...

Uh, 772 MB of RAM being stressed?

As in, none, basically.

I assume that OC is nowhere close to stable, as you need to actually be utilizing some RAM to stress things w/ LinX.

Try max RAM.

[PolRoger]

bot@xs: That's the maximum VID and not the maximum safe voltage.

Depending on overclock/cpu the only specification that at times seems hard to hold is VTT @ 1.21v max

[ezaleina]

is it safe tu run 24/7 with 1.38vcore and 1.30vtt..?

[MetalRacer]

bot@xs: That's the maximum VID and not the maximum safe voltage.

Thanks for the info unclewebb. Up until now it was my understanding the max vtt was 1.35.

[cesthree]

One thing I find interesting is XMP profiles.

I am expecting a barrage of "Don't use XMP you FOOL, that's for NOOBS!", right about now.

Just here me out.

I have no problem with using XMP. I would like to gain a bit more understanding of what exactly the XMP profile changes.

I found this page at Intel's site:

http://www.intel.com/Consumer/Game/extreme-memory.htm

If you open one of the PDF's on the right of that page it lists some memory kits that are "Intel" supported.

Ok, so Intel supports XMP, and my Corsair Dominator GT's are XMP equipped and Intel badged.

When I enable XMP Profile, my VTT is raised to 1.35V. There is no problem with stability. I have run 20 passes LinX and Prime95 was stable on blend for 12+ hours.

So, if Intel will badge and support XMP memory kits, clearly 1.21V VTT can be surpassed and is supported.

What do you think?

I will be posting here and EVGA forums soon with my latest OC results. Nothing amazing, and I might need some insight from some of you.

[SimpleTECH]

So, if Intel will badge and support XMP memory kits, clearly 1.21V VTT can be surpassed and is supported.

What do you think?

It has to be higher. My G.Skills can't do 2200 unless I up my VTT to 1.36V.

I'm surprised that the maximum "safe" Vcore is 1.55V - not complaining though.

[-=[kz-0]=-]

i'd like to get help from you guys..my i7 860 right now is on its sweet spot @ 3.8Ghz with 1.28v vcore 1.264v on VTT 1.87v on PLL can u suggest any setting for 4ghz??i tried a lot of combinations well all fail in middle of tests..

board is Asrock P55 Pro..with bios 2.2..

any help will be appreciated..Thanks!!

[mngdew]

Here is my first P55 build...



Still tweaking...the Corsair 8gb of memory is really giving me headaches...If I run it at 1600mhz 9-9-9-24, then the MB only sees 4GB instead of 8GB...If I run it at 1200 MHZ with 7-7-7-20 timings it sees all 8GB?? I think this is an EVGA issue...

My i7 920 running ~4.1Ghz pumps out ~54GFlops running LinX, but I noticed yours only doing ~43GFlops. Is that normal for an i7 860 @ 4.3Ghz?

[cesthree]

Max Static Overclock.

200 x 20. 4.0Ghz @ 1.35V VCore. 1.4V VTT. HT Enabled. Without VDroop.

i7-860 SLBJJ. Batch # L930B396




Stopped adding VCore when attempting a 4.2Ghz clock due to temperature limitations.

200 BCLK was possible with 14x CPU multiplier @ 1.35V VTT. Raising the CPU multiplier to 3.6 and above required increased VTT. 1.4 and no less was required for both 3.8Ghz and 4.0Ghz.

Also, 3.8Ghz @ 1.300V VCore was stable as well.







Here is my thread at EVGA Forums.

http://www.evga.com/forums/tm.aspx?h...mpage=1#120270

EDIT: Note about temps. Screenshot WITH 3DMark results had Realtemp reset. Screenshot WITHOUT 3DMark shows temps reached while running Prime95 Blend and LinX with ALL memory selected.

[managerman]

My i7 920 running ~4.1Ghz pumps out ~54GFlops running LinX, but I noticed yours only doing ~43GFlops. Is that normal for an i7 860 @ 4.3Ghz?

I just ran a quick Linx @ 4.2Ghz. Now at ~52GFlops....much better...

-M