focusbob

Hi folks,

I am attempting to overclock my pc:
mobo: P6T deluxe v2, bios 0504
cpu: i7 920 d0
hsf: zalman 9500 w/adapter for i7
ram: 12gb corsair xms3 1600 (recommended settings: 9-9-9-24 1.6v)
video: PNY 9600gt
OS: vista x64

At 3.6 GHz, temps are 69-70C under heavy load, so this appears to be my limit. I am load testing with intelburntest in vista x64 (max ram, 15 runs, 16 threads). Although it passes intelburntest x15, during each run the computer becomes unresponsive for about half the run.

Specifically, the vista equivalent of the hourglass appears, the screen goes black (except for the hourglass), the taskbar reappears (black background remains), and the tabs for intelburntest and speedfan do not maximize. I'd like to know how I can minimally adjust my settings to stabalize my system. Most of all, I'd like to hear if people have opinions regarding what specific settings are causing the instability.

Important clue: When I was testing my system at stock settings with intelburntest (to make sure nothing was DOA), I originally inserted my total amount of RAM in the appropriate box (instead of choosing "maximum") and the same symptoms of instability appeared. When I set this to "maximum" instead, everything went smoothly. Is there a problem with my RAM settings?

BIOS settings (let me know if you need any other settings):

ai overclock tuner: manual
cpu ratio: 19
speedstep: disabled
bclk freq: 190
PCIE freq: 100
DRAM freq: ddr3-1523Mhz
uclk freq: 3047Mhz
QPI Link Data rate: 6857MT/s

DRAM timing: 9-9-9-24
DRAM timing mode: 2N
all other DRAM settings on AUTO

CPU voltage: 1.20625
CPU PLL v: 1.80
QPI/DRAM core v: 1.20625
IOH v: 1.10
IOH PCIE v: 1.5
ICH v: 1.10
ICH PCIE v: 1.5
DRAM bus v: 1.6
all other "ai tweaker" settings on AUTO

PLEASE HELP!!! Thanks!

Aus_Karlos

Tweak your QPI voltage to 1.3v it might help.
Also is your Uncore multiplier in a 2:1 ratio of your RAM multiplier. having these two in a 2:1 ratio drastically improves stability under load.
Also boost your Vcore to 1.3v it can go as high as 1.35v if need be, and what is your VTT voltage set to?

Also you might want to max out your CPU multi and back down on the bclk freq. 190 is very high for that board you might want to keep it around 170-175.

focusbob

Thanks for your response!

Prior to recieving your post, I tried to solve this thing myself. I lowered my clock speed to 3.4 Ghz, and the system was stable. Part of why I lowered the clock speed was because I felt my temps were kind of high. I decided to download real temp and core temp to see what my temps were with different programs (I was using speedfan), and holy crap was I alarmed! At 3.4Ghz my system was spiking at 82C!! And this is at pretty much stock voltages! So, my question is kind of different now: This seems unusually high for my setup. I have 4 120mm case fans running full speed, my cpu cooler is not the best (zalman 9500), but still! My ambient temps are 78F. My processor is d0.

I have set maybe a dozen hsf; I don't think I messed it up. Why are my temps so high? What would you do if you were in my position?

(to answer your questions, it doesn't seem like upping the cpu voltages is a good idea because of my temps. My uncore is at a 2:1 ratio of the ram multiplier. I don't see any option for VTT voltage in my bios (when I googled this for my board, I saw people referring to this as QPI voltage).

Thanks

Aus_Karlos

Well ~85c is the max for the i7 cores so your still under the line. The Vcore voltage is to low at 1.2v for 3.6ghz this is why its unstable. A better CPU cooler will be a good idea same with some high quality thermal paste like Arctic Silver 5.

But decreasing the bclk freq and increasing the CPU multi to compensate for the clock frequency may decrease those temps a little.

What case do you have?

focusbob

I use AS5, and my case is an antec p180. I may consider a new hsf, but it would be such a pain because I would have to reinstall the mobo (to remove the zalman backplate). The 82C max temps are with the bclk at 170 and multiplier at 20. I tried a multiplier of 21 (with lower bclk), and the computer won't even boot.

My concern is that these temps seem abnormally high given my setup. I'd like to know why they're so high so I don't waste money and time on an upgrade that won't make a difference. I could reseat my zalman 9500, but something tells me this won't make a difference (because I felt good about how I seated it the first time).

I also could just live with the 3.4Ghz and 82C temps, the temps are safe according to what you're telling me, but I feel like I'm being jipped with this proc; that I should be able to get a lot more out of it; at least 3.6Ghz with safe temps.

greenbrucelee

the temps could be that high for a number of reasons like:- heatsink not sufficient for cooling, Artic silver not applied properly, not enough cool air coming into the system, hot air not being pushed out well enough etc etc.

focusbob

Hi greenbrucelee,

That makes sense; I guess what I'm looking for, though, is: if this were your system, what steps would you take to try to lower temps and in what order would you take these steps?

Thanks

greenbrucelee

If it were my system I would get rid of the Zalman cooler and get the xigmatex or Noctua coolers, I would also swap cases for an Antec 1200

Aus_Karlos

If you have just applied thermal paste AS5 takes about 200hrs "On" with 6hrs a day shutdown for it to mold to the CPU and the heatsink properly. Once this is done all the air would of been pushed out and thermal conductivity will be at its max level, you will also notice upto a 5c drop.

But you will find 3.6ghz - 3.8ghz will be your limit for air cooled, if your aiming for 4ghz then you will need to get Liquid cooling. You may also need a different case as that case only has a single fan. Not ideal for an overclocking case.

greenbrucelee

Or an air cooled system like mine :)

Dacads

you need to have something like 2 intake and 2 exhaust fans.
no good if all are just blowing around inside case
This apevia 120mm fan is great, air flow is around 57.67 CFM with only a 24.7 dBA noise level. Get 4 of these if your current fans are not that great and make sure you get a new case if required

Dacads

focusbob

Thanks for the suggestions!

My P180 came with 3 fans (intake, rear, blowhole), and I installed a fourth (lower chamber); they're all pretty high CFM (I'm sure they could be higher). I have them all set on the highest setting, so air blowing around inside the case may be an issue. Any suggestions regarding how to set the various fans (i.e., low, med, high) for optimal cooling? Anyway, I think the case cooling is fairly good, and its probably the cpu cooler that is more at fault (and perhaps not enough time for the as5 to settle in as Aus_Karlos suggested). Laziness very well may prevent me from replacing the hsf, at least for the time being.

focusbob

I tend to be persistent to a fault when something I'm working on is problematic. I scoured the internet and did some experimenting and learned some very valuable lessons that I think others will benefit from if they come across this forum:

1) TURN YOUR SCREENSAVER OFF when load testing. I can't be the only moron who forgot this one! Turns out, this was my "instability"; the screensaver kicking in. I turned it off, and the instability disappeared.

2) If you have the d0 stepping of the i7 920, in terms of vcore, less is more! I turned my vcore (and QPI) down to 1.20v in the bios, and I turned off the vdroop control (load line calibration?). Along with some other tweaks (below), I am now rocking 3.6Ghz, linpack stable for 20 trials. The best part is that my temps do not exceed 76C (as opposed to the 83C I was getting with higher vcore). I tried boosting freqs to 3.8Ghz with 1.2v, but it wasn't happening (not surprisingly!). I may be able to get 3.7 though, I'm still messing around.

3) Turn of spread spectrum (cpu and pci-e). I will not pretend to be an expert on what these settings do, but disabling them (along with my reduced vcore) allowed what I think is a very high overclock for stock voltage (lower than stock when you account for vcore droop).

Another question for the forum: is 76C under load acceptable temps? I'm looking to raise temps to a point where the longetivity of my proc will not be significantly affected. Do folks think 76C under full load will reduce longetivity? Do folks think I could get away with higher temps without reducing longetivity? This will determine if I try to bump vcore a bit and go for higher frequencies (e.g., 3.8).

Thanks again for your help!

greenbrucelee

some people say that i7s have a max temp of 80 but I would prefer lower if I had one.

Core 2 duos max at 72 but I would never dream of going over 60 degrees. Overlocking to any level will shorten the life of a cpu especially if using high voltages.

Aus_Karlos

I7s max temps actually vary from CPU to CPU. If you get two I7-920 and overclocked them all the same you could see a 5c-15c different in Max Temp. While one may only be able to work at 80c the other could function at 90c fine.

However i would advise enabling vdroop (LLC) again, this will keep your voltages more stable when your system is underload.