i7 950 4ghz Temps in Snow Leopard and Windows 7

[emches]

I believe I've found stability at 4ghz. I've made 24hour long tests in Linx and Prime95 without crashing or errors. My settings are as follows:
174x23
Ram underclocked @ 1392mhz
vcore @ 1.28
QPI/Vtt @ 1.25
CPU PLL @ 1.70
QPI PLL @ 1.20
DRAM @ 1.64
Everything else auto/default

After doing various kext fixes in Snow Leopard Prime95 testing yields a max of 75c.
In Windows 7 using Linx the max is 69c. My ambient room temp is 28c.

I am using H50 Push/Pull as exhaust in HAF 912 case with 4 intakes (front, side) and 2 exhaust (rear, top).

Anyone else getting higher temps in Snow Leopard? Are these numbers anything to worry about?

 

[mmaenpaa]

You should be getting same temperatures on both operating systems if ambient temperature is same and you use same stress test on both. Run Prime95 on both and check temperatures.

 

[emches]

Using Prime95 in Win7 my max temp was 67c after about 13-14 hrs of testing using the maximum heat test. In Snow Leopard it gets to mid 70s after 20mins.

 

[mmaenpaa]

I just did some testing with a power meter and my system actually seems to be using 8 W more when running Prime95 large FFT's on Windows. Difference is so small that it doesn't show at core temperatures but if anything temps should be lower in OS X. Is it possible that you have fans running slower in OS X or something else like that ? With radiator fans lower rpm would show up as big temperature difference.

 

[emches]

I made sure to remove fan power management options in BIOS so iStat menu's show all fans running at full RPM. I think this has something to do with an improperly installed or missing kext. Prior to installing ACPIThermal.kext my temps would run as high as mid 80's... I guess as long as It doesn't go past 75 I have nothing to worry about?

 

[mmaenpaa]

75 C with Prime95 is no problem, you will never get so high temps with any real world applications. But I still wonder why temps would be higher in OS X, I've never seen such thing with any of my systems.

 

[emches]

It is indeed odd! Another odd thing I noticed is that the temps are exactly the same side by side for the 1st 15 mins of Prime95 testing in SL and Win 7 but at around the 20min mark the SL temps shoot up to 75 and in Win7 they shoot up to 67...

 

[Jabulani Jonny]

My 950 runs 47-48C with nothing but Chrome open in OSX. I do feel like that's a bit high, but I've tried a number of things and can't really get it lower. Not to mention that I'm using a Corsair H50 liquid cooler too. One thing that is interesting is that the BIOS always shows the temps being a good 5-6 degrees lower than iStat. Haven't installed Windows 7 yet to test, but will soon.

One interesting thing to note is that earlier today I deleted all the unnecessary kexts from my /Extra folder and updated the system monitoring kexts via the latest multibeast. When I booted back up my temps were 38. I was stoked except I was dorking around and now I can't get it to back there. May try that trick again though and see if it sticks.