Overclocking my i7 920?

[Steel Jaw]

I read that link and there's some major issues with it, for one it does not discuss VTT voltage.

 

As well, evrything I have read and seen for myself suggests you CANNOT o/c to even 3300 on 1.1 CPU v.

Edited December 23, 2010 by Mower

[EtherealN]

That varies a lot chip-to-chip. I've seen a 950 do 4GHz while at 1V exactly (that's right, overclocked AND undervolted at the same time) in a review over at OC3D.

[RSharpe]

Guides are exactly that. They're guides. They're not bibles with rules written in stone. They get you in the park, and get you thinking about what you need to think about, but you need to do a lot of the work yourself. For those who cannot bother working on it, they should hire someone to do it for them, and buy a custom built system with bin selected components.

[Steel Jaw]

Here's what I am finding with my own o/c.

 

Even though it fails with prime95, i get no issues under normal use and gaming/simming.

 

So, I am at a clock of 159 for 3300 and it is stable but fails prime95 after 1 minute.

 

CPU 1.35 v VTT +200mv.

[Druid_]

Hey Mower, what stepping is your i7 ? looks like it might be a C0 stepping version.

 

If you have a Gigabyte mobo, this an excellent link (prob good info in there for other mobo users also)

http://www.overclock.net/intel-motherboards/706509-official-gigabyte-ga-x58a-ud3r-ud5.html

 

Most i7-920 D0 stepping enthusiasts manage 4.0 Ghz on good air cooling

[Steel Jaw]

Hey Mower, what stepping is your i7 ? looks like it might be a C0 stepping version.

 

It is a D0, I was careful about getting that.

 

And I picked the EVGA mobo for its o/c ease.

 

Air cooling is excellent with a cooler master v8.

 

Go figure.

[CarneyUK]

No expert but just something I noticed, I have the D0 version i7 920 and have set CPU Voltage to 1.15 (as in previous post) as this was advised "D0 = 1.15v and C0 1.25 volt." If you have got it at 1.35v could that be too high and causing problems???

 

I've got 183x20 and 1.15v (CPU Voltage) with 3.6Ghz absolutely stable. From what I know the higher you clock the more voltage you need, but is there a pooint when it's too high???

 

Just a thought and as I said I'm no expert.

[Konovalov]

Yes voltage over 1.45-1.5 is max for i7 as far as I recall.

 

There should be a clause with overclocking saying mileage may vary. No two systems are alike and even more so of CPU's.

[Steel Jaw]

Now this is curious: after I dropped the CPU to 1.15 v (from 1.35), it's stable @ 3300.

 

By stable, I mean no CTDs when I game. Fecking Prime95 still will cause a freeze so I find it suspect.

[CarneyUK]

Just another food for thought...what's the VTT +200mv for? Can it be set to auto? (I haven't got a clue what it is btw)

 

Is it worth downloading Prime 95 again from a different location??

[Steel Jaw]

VTT now at 150mv, it must be within .5 v of the DIMM v, since my DDR3 spec is 1.65 v the VTT needs to keep pace (default is 1.1)

[CarneyUK]

Was just having a llok for a better understanding myself and found this

 

http://forums.overclockersclub.com/index.php?showtopic=171976&st=12

 

so yeah should be within .5v.

 

Is Prime 95 falult cleared??

[Druid_]

A lot of enthusiasts are able to reach 4ghz on a D0 stepping I7-920 with a Vcore of around 1.275v

 

When overclocking, start by underclocking your memory (use a high ratio to do so) so at least you will know its the CPU causing problems and not your memory.

 

A simple and quick guide (please search web for more in depth versions)

1) Set your multiplier to 20, your Bclk to 200 Mhz.

2) Disable Intel Turbo boost and any other power saving options (e.g. EIST, C1)

3) Drop your memory ratio to 6x (it will run at 1200 Mhz, you can tweak it higher later)

4) Set Uncore frequency to run at 2 x your DDR3 set memory speed (in this case 1200 Mhz) so in this case 2.4 Ghz (in some BIOS it might be a multiplier, in which case set it to 12 (i.e. 12 x 200 Mhz) or even slightly higher but not lower.

5) Set QPI/VTT to 1.5v and QPI PLL at default

6) Set CPU Vcore to 1.3V

 

If you have OC probs then you can raise the CPU Vcore to 1.4V but do so in small increments.

 

Use the freeware 'CPUID Hardware monitor' to check your BIOS voltages are close to those set in your BIOS.

 

Once you have a stable CPU overclock, you can start playing with your memory speed and timings to increase performance further.

 

Good luck.

[Steel Jaw]

3) Drop your memory ratio to 6x (it will run at 1200 Mhz, you can tweak it higher later)

 

Never thought of trying that and it has increased stabilty, even if I only ran it @ the ~900 mhz then even that is fast.

 

EDIT: so I set a 6x memory ratio and with a 175 clock I get 3500 stable with Prime95 and 1080 mhz RAM. CPU v 1.20.

 

SO, the moral so for me is to not push RAM too hard.

Edited December 24, 2010 by Mower

[Konovalov]

Yep. That is excellent advise. That's how I overclocked my E6600 back in the day. Turn everything down and OC the CPU. Stress test it and see how far you can take it. Then move onto memory and so on. That way it is easier to locate the cause of a failed OC. Little steps/changes at a time.

[Druid_]

EDIT: so I set a 6x memory ratio and with a 175 clock I get 3500 stable with Prime95 and 1080 mhz RAM. CPU v 1.20.

Great, ok now try upping the voltage on your CPU from 1.2v to 1.3v and start increasing your BKCLK in small increments. Hopefully, you'll reach 200. This will also increase your memory to 1200 Mhz which it should manage easily.