core 2 quadro overclocked...

[deadalvs]

hi all...

i do a lot of 3D renderings that need a lot of cpu power and use all cores available. so i bought a nice new system with a core 2 quadro 2.66 GHz cpu and have it be water-cooled.

i overclocked it to 3.66 GHz and pushed a little the voltage and it did great and stable tests with 100% cpu stress for over an hour and also with cinebench tests.

then i tried my rendering software and the software crashed every time i ran a benchmark, after about two minutes. i went down to 3.33 GHz which seems stable now with a maximum of 13 degrees under the red mark in the intel desktop utilities' heat monitor.

my question now is... could the pushing of the voltage be a problem for the overall stability or what could have caused the application crash ? i have to say again that the intel stress test was fulfilled perfectly...

what could be the problem ?

i use an intel bad axe 2 motherboard.

thanks for any suggestion !

 

[JAG87]

make sure you do large fft when stress testing, because having a stable cpu crunching small fft means squat. when rendering ram plays a major role.

next to that, up the voltage... but dont get to happy with it (keep it under 1.5)

 

[Duvie]

Where do I start!!!

1) the 975x chipsets have done worse then the p65p chipsets like the Asus P5B-deluxe

2) Are you using a CAD based video card? if not what are the crashes like? program errors only or BSOD or hardlocks? May look at video drivers.

3) How are you stress testing the 4 cores? I had to run 4 instances of Prime95 or 4 instances of F@H. So you may not be stressing all 4 cores until you start rendering in the app and it is showing you are not stable.

4)It has been seen by many that these chips cannot take high fsb and this may be related to current round of mobos. So since you have an X version with unlocekd multis try running below 333fsb...meaning try these...

12x266 = 2.66ghz
10x333 = 3.33ghz
13x266 = 3.466ghz
11x333= 3.66ghz

I found low multi high fsb was tough to get stable but higher multi and lower fsb easy...then you can use the memroy dividers at 333 to run 800 to 1000ddr2 with the 2.5x and 3x multi...or...you could run 3x or 4x for 800 and 1066ddr2....

i recommend 800ddr2 at least in any current config. there is a nice performance increase versus 533 or 667 in the test I have run. With 4 cores memory bottlenecks seem to become more apparent.


what stepping is your cpu? Mine is B0 stepping but an ES model.

I can do 3.2ghz at 12x266 100% stable for 4 weeks now with 1.4v set in bios and loads to 1.31v under load. the vdroop is tremendous on the DS3. With a C2D overclocked to 3.4ghz with 1.45v only sees .02-.03v of drrop. This is 3 times that now.

I can also do 3.3ghz 10x330 100% stable with 1.425v set in bios and 1.33v load. Temps with core temp get to 69c.

If I run 3.33ghz I need 1.43125-1.4375v set in bios. However it never crashes but experiences something similar to throttling. NOt multiplier halfing, or vid drop, but actual 2 cores (always in pairs) with drop cpu speed in half...though again no change in fsb in multiplier as seen by RMclock...

I recommend you get RMCLOCK app. very nice!!!

It may be temps as I see 70-71c. However at the lower vcore at 3.2ghz I modded the fan top drop below 400rpm and let the temps get to 80c and it would not throttle. So I am at a lost until I try this chip on 2 other boards, which is my plan...

 

[Shimmishim]

So confused.... some people say retail QX6700 doesn't ahve unlocked mults... others say it does...

I though that the ES's were the ones with unlocked mults on C2Q... argh.... so confused!

 

[The-Noid]

Anything with the word Extreme in it has unlocked multi.

 

[Soulkeeper]

you should push the clock speed as far as you can while keeping default voltage
only when it becomes unstable raise the voltage in the smallest possible increment
the access heat and electron migration can be more app to cause instability than clock speed alone
but yeah mess with those bios setting and make sure your mem settings and chipset specific settings aren't becoming a limiting factor at your desired speed

good luck

 

[deadalvs]

thanks until now !

i use a ASUS EN7950GT 512 MB graphics card.

the crashes are like this: the application closes down and then this "send report to microsoft field" shows.

i use PC-8500 ram, whicht can run at 1066 MHz but as i see in the BIOS, it allows only 800 MHz which doesn't speed up rendering in the tests.

* * *

will decreasing the cpu voltage also help to produce less heat ? i' ve seen now at 3.33 GHz that with my settings (see below) i reach very high temperatures, checked with the intel desktop utilities / hardware monitor. there, the temperature got up to 8 degrees that's nearly in the red part !

cpu voltage: 1.5375
(might that be too hign ?)
enhanced power slope: enabled
front side bus voltage: 1.250

multiplier override: manual
host clock frequency: manual

processor multiplier: 10
host clock frequency: 333

--> 3.33 GHz

system memory speed: set to 667 MHz (it is 1066 MHz ram)
memory voltage: 1.84

* * *

 

[Duvie]

Damn!!!

First off the cpu voltage seems a bit too high....

secondly 1.84v may be too low for even 667ddr2. you may wish to bump that to 2.0v at least and let the timings loosen up a bit

Third...try disabling the power slope.

 

[deadalvs]

ok... i am trying now these settings:

ram: 533, 2.0 V
cpu 266 1.425 V
factor 13
--> 3.45 GHz

i'll watch for temperature... exact temps were per core 86 to 89 degrees before !!

i need a stable computer in first place... or so i am told...

 

[Soulkeeper]

that cpu runs hot, if it's anything like my 2.8e P4 prescott raising the voltage does pretty much nothing

 

[deadalvs]

technical question. could i run this cpu with fsb of 400 ? so i could use 800 MHz for the ram and a multiplier of 8 or 9 ?

* * *

my last test gave back core temperatures of 69, which is very low ! great !

 

[deadalvs]

would this be exactly 400 or something "strange" ?

nice thread:
http://sg.vr-zone.com/?i=4130&s=1

 

[Duvie]

I wouldn't....MOst of these things dont like to run high fsb....You are better to run like I suggested....

Just use memory dividers to run 800ddr2 at lower then 400fsb. You can do it.... I can run 800ddr2 at 266fsb, 333fsb, and 400fsb.....