OC i7 920 to 3,33 (QPI link speed...?)

[J van E]

I am OC'ing my i7 920 to 3,33 on my Gigabyte EX58-UD5 motherboard. I still have a stock cooler, but this should be possible (at least in the winter) and indeed it is. But since I am completely new to this I am afraid I might be overlooking something important. Thing may work now but I don't want my new system to be burned out in a month or so...!

I already had things like EIST, C1E and HT disabled. So now I did the following: in the BIOS I went to the M.I.T. screen and there I

1. simply raised BLCK from 133 to 166

2. set Performance Enhance to Standard (instead of Turbo)

3. Set the memory multiplier to 8 (instead of 10) to let my 1333 mem run at 1333.

In the Advanced CPU page I disabled another (???) Turbo option (I though it was the same but turning off one didn't turn off the other).

That's it... I left my ram at the default 9-9-9-24. Only thing I noticed was that the QPI link speed went up a lot to something like 6... where it was something 4,# (forgor the exact numbers). Is this anything to worry about? Should I change that? If so, how...? Because it's not editable.

I do remember reading here and there getting the i7 920 OC'ed to 3,33 was very easy because yuo'd only have to edit the BLCK, but I already had to do more. I wonder if I still missed anything. And of that higher QPI link speed is something to worry about.

 

[masteryoda34]

You're QPI is probably running at 166*18 = 2988MHz now instead of the default 133*18 = 2400MHz. Anything under 4000MHz QPI is generally stable. As long as your system is stable it should be fine. You can check your QPI speed in CPU-Z. (search google if you don't have it.)

 

[J van E]

Yes, thanks, CPU-Z says it's running at 2988.0 mhZ. So I don't have to look at uncore, voltages or things like that at all?

I noticed on the SPD page of CPU-Z that the max bandwith of my RAM is 667 Mhz. Underneath are timing tables and it says that 667 Mhz should run at
CAS# latency 9.0
RAS# to CAS# 10
RAS# Precharge 10
tRAS 25
tRC 34

My supplier entered 9-9-9-24 manually into the BIOS. With the new BIOS I can also set tRC but I left that at auto. Should I change these settings? Or should I set the timings all to AUTO? Or doesn't it make any difference...?

I am going to test how stable th system is by letting Orhos run on all cores (4 since I disabled HT). I think it will be fine. The only problem I have to look out for is heat, since I use the stock cooler. Right now it's winter so I wonder if I will be able to OC during the summer... on my attic... 😉 I mean, heat is all I have to watch, right? My settings aren't too extreme for my videocard, ram and cpu...?

 

[masteryoda34]

Uncore will be running at 166*16=2656. That should be fine, again as long as it is stable. Voltages only change when you change them in the BIOS.

If your memory is rated for 1333 9-9-9-24 then thats probably what you should run it at. The timings don't make that much difference (generally < 1%) unless you are extremely concerned with performance.

Oh and BTW, when CPU-Z says the memory is running at 667MHz, that is the same as 1333MHz. (DDR = Double Data Rate.)

 

[aigomorla]

just try to keep your QPI link speed below 4000.

I heard if you try to go higher, you will run into problems.

 

[J van E]

Well... that's easy OC'ing indeed then...! I just played a game for an hour or so and noticed the temp didn't get above 50. That game probably doesn't stress the CPU. 😉 I also did a simple test with FSX and fps went from 21.5 to 25,5 or something like that. Doesn't seem much but that's about 20%! With FSX that's a lot.

I do not intend to OC any higher, so I'll never reach that QPI 4000.

Tomorrow I will do some long CPU-stresstests but I wonder if any normal app or game will ever really stress the CPU like a stresstest will...? Hm, pity I didn't get a better cooler immediately... Installing another one will require a bracket going underneath the mobo afaik which is too complicated for me... But well, 3.33 is already nice!

 

[Shmee]

Try 19x for core multi, I have heard that i7's do best with odd multi. Currently at 160*19 on my UD5. Looking for a good guide for the motherboard. Also looking for a better cooler.