• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

Fresh OC restart.

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.


Sep 14, 2009
Im going to restart OCing my rig again soon. Last time I did not like how things turned out. I was OCing straight to 4.0ghz and it ended horribly. On tuesday I started my comp up and left it alone, so it was idling... I went to get some stuff done around the house and I came back to see a white greyish screen that was what I would see if I was stress testing my OC and it crashed. Im assuming its usually refered to as a hard lockup. Anyways, when I went to restart my computer, it would not get past the "starting windows" screen with the windows logo (win 7). It would actually go to a black screen with my mouse cursor on it and movable. But nothing more. After hours upon hours of experimenting and researching for answers. Nothing worked! So today I spent all afternoon/evening reinstalling windows 7 and getting everything set up.

Now I have decided that I will not take a giant leap from stock to 4.0ghz this time. I was to get to 4ghz eventually but I think I will take it at decent steps over a long period of time. I do not want to do 3-5mhz increases in BLCLK freq and spend hours going through crashes and such to get a good OC. I want to get to a 4.0ghz OC with minimal crashes!

Stock is 2.66ghz
I was thinking of going with a 3.2ghz leap first. Wait a few days to about a week, then go to 3.6, then 3.8, afterwords I would go up slowly to 4.0ghz goal.

What I would like to know is what I should look at for voltages. Last time when my computer crashed while idling (first time ever), I was at 4.0ghz (200x20) 1.29v vcore, 1.25 qpi, 1.65 vdimm, CIE disabled, speedstep disabled, turbo disabled, HT on.

I was looking into more information and ran across a few questions:

1. Which is better? with or without vdroop; I heard that without is a better idea. From my understanding, without vdroop, vcore will go up when under load, so I need to use about ~.1v less then what I want for load. With vdroop, vcore will go down when under load, so u look for a voltage that is ~.15v higher then what you want under load. Is this correct? And if it is, I would assume without vdroop would be better; please explain the advantages and disadvantages.

2. What are all these VTT settings? I notice there is a cpu vtt where u can add something like +25mV and so on. Explain these settings please.

3. For ram settings, I know that I should aim for 1600mhz and go with 7-7-7-24 with 1t command rate. But what should I do with tRFC? It is on auto and sits at around 88?

Toss me out some numbers for voltages. I will start with trying to OC to 3.4ghz first and go from there.

I did some more research earlier today; looked at my batch number of my i7 920, off the top of my head... 3919Axxx
I looked at a list of people who are at 4ghz and higher on the evga forums and found 3 people who have 3919Axxx batch numbers.

#1 4.2ghz 1.4875v vcore with vdroop 46C min to 94C max
This one is a bit ridiculous. But it is the only one who has a 4.2ghz setup.

#2 4ghz 1.27v idle / 1.317 load 33C-72C
Im guessing he is without vdroop cause of load/idle vcore; this is a much more reasonable setup.

#3 4ghz 1.35v with vdroop 43C - 78C
And this is the last one, seems like a good setup too.

Out of those 3, #2 really stands out. But every chip is different so I will try finding out what to do.

One long writeup, hopefully I can get some idea of what to do with this new procedure.
Last edited:


I been Dolk'ed Senior
Jan 14, 2003
Stuttgart, Germany
Guess this - "4.0ghz (200x20) 1.92v vcore" is actually 1.29v?

Honestly, your settings look good overall. You may have a CPU that won't do much more than 4GHz. vDimm is good, QPI is good, so it's all down to CPU voltage and BLCK. I'd probably start around 20x180 and go up from there. You might need a bit over 1.3v to be stable at 4GHz, but first see how high you can go on stock voltage.

The other CPUs you show with roughly the same batch are a good comparison, but don't base everything off it.

If you can't get to 3.8GHz with under 1.28v I'll be surprised. I like loadline calibration, so I recommend it.

Can you provide a link to the memory you purchased? I just want to make sure it's capable of those timings with 1t comand rate. I would plug in 7-7-7-24 and leave the rest of the settings on AUTO.

You shouldn't need to touch all the other vtt settings.

What CPU cooler do you have? and you might consider running memtest on your sticks once you get close to it's rated speed.


Sep 14, 2009
Yes, sorry, it is 1.29v, changed it in OP.

I think my settings were fine, maybe my vcore was too low cause when I did a stress test, my voltage would drop down cause of vdroop.

The ram is this: http://www.ocztechnology.com/products/memory/ocz_ddr3_pc3_12800_platinum_low_voltage_triple_channel
I have it set to 7-7-7-24 at 1t

I set my mild OC today: 3ghz 150x20, turbo off; have ram multiplier at 2:10, so ram is actually downclocked atm to 1500mhz. I set vdimm to 1.65v and qpi pll vcore to 1.25v since your want the qpi within .5 of the vdimm. I set my fan speeds to manual and all 100%.

What does PLL mean in some of my voltage settings?

I got the megahalem cpu cooler with 2 fans, currently only one fan is installed due to my issue with having the 2nd fan on (need to get some wire and make some custom clips for the 2nd fan since I will be putting a filter between the fan and the cpu itself or putting the filter ontop of the fan (to get rid of that headache causing buzzing noise).

I have ran memtest on my ram when I bought it for hours on end and overnight. It was good to go at 1600mgz and those timings i set earlier.