I7 920 OC. I have to be missing something.

El Nacho

Noobie Cheese
Joined
Jan 22, 2002
Messages
2,258
Specs:
I7 920
EVG SLI LE
3x2 Corsair XMS 1600

when i first built the system 6m ago, I was still on the stock HS. In a "lets just see" moment, I set the BCLK to 166 and everything else to auto/stock. ran at 3.4 with no issues. I picked up a corsair A70 recently and figured it was time to see how far I could go. Pushed BCLK to 176, booted fine and burntest ran fine. BCLK to 186 started to cause some issue. After toying with the vcore and ram voltage, I find out the vdrop option is the issue and turn it off. vcore around 1.32 and ram at 1.65

Push BCLK to 196 and end up setting vcore to 1.35 to get through the first pass of burntest, fails on the second pass. Quick test at 1.36 doesn't make it stable so I decide to settle on the BCLK @ 186 for 3.8.

Start to back down the voltages and it keeps going lower and lower. Currently at 1.27 for vcore and 1.5 for ram. Pretty sure I can go lower on the vcore, but I stopped to see if something else may have been stopping me from a higher over clock. So am I missing something or should that much more voltage not get me over 4ghz?
 
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I assume the RAM is rated for 1.5v at it's advertised speed and timings?

I suggest you keep 1.35v on the vcore and push the QPI/DRAM voltage to 1.375v. What is your QPI/DRAM currently?
 
ram is rated at 1.65. For QPI/DRAM I assume you your talking about VTT?
 
yeah mine is similar to yours, but I'll have to double check if I have one for qpi. Just got confused when they were put together.
 
I'm new to overclocking, saw this thread and figured it would be a good place to ask a question. I have an i7 930 that I want to overclock in the future. Currently running the stock cooler, and frankly I think it sucks. On stock settings running Handbrake my CPU pushes 82 degrees Celsius in the basement of my house which is usually pretty chilly. I bumped the Bclock frequency up to 140 from 133 MHz just to get a taste of overclocking. The CPU now runs at 3.08 GHz and Handbrake pushes the CPU up an additional 10 degrees from stock settings under full burn.

Now, I know my stock cooler isn't going to cut it... At all.

My question for you overclockers is when will I know to raise the voltage levels? I just read the Maximum PC tutorial/how to on overclocking i7's. They mentioned some people getting high clocks on stock voltage as well as needing to raise voltage levels. Is there a certain way I should start out overclocking? Once I get my after market cooler I'd like to push the 4 GHz level with this chip.
 
My question for you overclockers is when will I know to raise the voltage levels? I just read the Maximum PC tutorial/how to on overclocking i7's. They mentioned some people getting high clocks on stock voltage as well as needing to raise voltage levels. Is there a certain way I should start out overclocking? Once I get my after market cooler I'd like to push the 4 GHz level with this chip.
Definitely get a new HSF. Hyper 212+ and A70 come to mind as far as performance/price are concerned.

As far as voltage, you'll know when to raise the voltages (or atleast mess with them) when you get instability - not booting into Windows, random errors, blue screens, random restarts, failed/crashing apps, etc... LinX, OCCT, and Prime95 along with MemTest86/MemTest86+ are all great ways to test stability but require time. Also, don't push it too far and keep a mental target for how far you are willing to push it based on what other people have achieved (you may not match them though, so keep that in mind - its a crap shoot) and the maximum documented range. Read, read, read, keep notes and read some more.

Sorry to have hijacked the thread. :(
 
Definitely get a new HSF. Hyper 212+ and A70 come to mind as far as performance/price are concerned.

As far as voltage, you'll know when to raise the voltages (or atleast mess with them) when you get instability - not booting into Windows, random errors, blue screens, random restarts, failed/crashing apps, etc... LinX, OCCT, and Prime95 along with MemTest86/MemTest86+ are all great ways to test stability but require time. Also, don't push it too far and keep a mental target for how far you are willing to push it based on what other people have achieved (you may not match them though, so keep that in mind - its a crap shoot) and the maximum documented range. Read, read, read, keep notes and read some more.

Sorry to have hijacked the thread. :(

Gotcha. Appreciate the response. I'm sorry to have hijacked the thread as well, I figured talking about voltages and that it was about a 920 it'd be "okay" if I asked a question here. Didn't want to start a new thread over a stupid question I had.

Anyway, I understand the concept of adding voltage to the CPU, QPI, and RAM. I printed off some paperwork from Max. PC's walk through and I've been reading other forums as well. Good advice, thank you.

Oh by the way, I've already order the new Zalman cool on order, I believe it's the 9900CNP MAX.
 
thanks, I'll read it over. I think my next step is to see how low I can go with vcore at this speed. Then work from there.
 
It sounds like you aren't doing anything wrong, your CPU just requires a lot more voltage to go from 3.8 GHz to 4.0 GHz. I have the same problem with my 920. At 1.3v its completely stable at 3.6 GHz, To get stable at 3.8 GHz I have to bump the voltage up to 1.4v. After playing around with it for a couple of hours I decided that 3.6 GHz at 1.3v would offer enough performance and that trying to push for the last MHz was requiring too much power for my liking.
 
It sounds like you aren't doing anything wrong, your CPU just requires a lot more voltage to go from 3.8 GHz to 4.0 GHz. I have the same problem with my 920. At 1.3v its completely stable at 3.6 GHz, To get stable at 3.8 GHz I have to bump the voltage up to 1.4v. After playing around with it for a couple of hours I decided that 3.6 GHz at 1.3v would offer enough performance and that trying to push for the last MHz was requiring too much power for my liking.

What made you decide it was to much power for your liking?
 
thanks, I'll read it over. I think my next step is to see how low I can go with vcore at this speed. Then work from there.

I have a release day Ci7 920.
I have it clocked solid at 200 BClk on my evga Classified NF200 board.
I run the VCore at 1.4875 Volts and it's been running there for almost two years.

These cpus can handle a pretty good VCore.
Check your stepping, my 920 is a C0. The D0 versions are apparently much better overclockers if you have the board that can go over 200 BClk.
 
down to 1.23 on the vcore for 186x20. Tried vocre @ 1.35, qpi @ 1.34 and dram @ 1.65 and I still couldnt get 196X20.

Any ideas on how to figure out what is limiting me? I doubt the chip because of the vcore I can run it at now. I guess next I'll drop the ram speed down and see if that is the issue. Maybe the board?

EDIT: chip is a d0
 
here is what mine shows,
http://www.xbitlabs.com/images/mainboards/evga-x58-sli-le/bios_volt.jpg

So the QPI PLL vcore should be bumped up?

Yup. Mine is at 1.5v. Considered high by the mobo (Red) but OC Genie set it to 1.587v when I played with that feature for a lower OC so I see no issue with 1.5v.

I've got my 950 up to 200x21 for 4.2GHZ. (Default 1600MHz RAM speed.) I need 1.4vcore, 1.9 CPU PLL and the aforementioned 1.5v QPI to maintain stability but it is stable. Oh, I bumped the NB and SB a bit to after a failed OC but I think it may have been more a vcore issue, which I have since raised. I haven't played with it for a couple days to see if it's actually needed. Once it was P95 stable I started playing games again. (OCing can get tiresome after many reboots/setting adjusts/stability tests so I do it in spurts. Couple days on. couple days off.)
 
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