Core temps?

[obmot]

Hi again, another question that I cant seem to resolve despite reading a ton of threads and various websites.

My new build is up and running very well. Since the thermaltake CPU cooler didnt mount flush on my mobo, I opted to install the stock Intel CPU cooler (Core i5 2.8GHz quadcore). I then decided to try some "core temp" stress and monitoring programs - but have ended up entirely befuddled...

At first, I was happy because the new build seems to run extremely cool (case never even gets warm to the touch, exhaust air leaves at 73-75 degrees F under normal PC use for over 2 hours) (ambient room temp 72).

However, I loaded a core temp program and a core stress program. When I put the 4 cores under 100% load, the "core temps" spiked within 10-20 seconds to 90 degrees C. YIKES! Yet only eventually did the CPU fan speed up a bit, and did a tiny bit of "warmish" air start venting from the case (76-77 degrees F or so).

Furthermore, when stopping the core stress test, the "core temps" drop just as fast to 34-40 degrees C.

So I have this hunch that something isn't right with how I am monitoring or interpreting temps. How can 4 cores temps go from 34 to 90 in 10-15 seconds even using just the stock cooler? And if my CPU is really "that hot" why is essentially no heat detectable around the CPU area or case? If the temp spikes that fast, why is the CPU fan only eventually and slowly moving from 2k RPM to 3k RPM (my old Dell desktop, the fans rev up almost immediately and attain jet like speeds upon CPU load, and the exhaust air is hot like a hair dryer).

In the end something just isnt making sense to me. I dont think my CPU is really at 90 degrees, particularly in < 20 seconds.

[ryuk999]

I doubt it really get's to 20C, what program are you using to find the temp? Also try reseating your cpu fan because sometimes you'll see really high temps if it's not seated correctly.

[obmot]

thanks ryuk, the heatsink is seated perfectly (the former one was also seated to the CPU firmly, but i didnt like the back side); I used Core Temp and Fan Speed freeware programs. Interestingly, at idle these programs will say cores are at 40 degrees C, but the bios says it is 65C.

I am beginning to think the sensors on the mobo are out of whack or something.

I can run my 2005 dell dual core, load up a few mere videos and it runs far hotter than the new PC under 4-core load for 10 minutes, measured by the tried and true "touch the case, feel the air coming out" test.

[Raiden619]

What core temp program and core stress temp program are u running

[obmot]

Raiden, I used 'Core Temp' (temp measurement) and 'Fan Speed' (temp measurement and fan speed monitor) and 'Core Damage' (CPU stress) programs.

FanSpeed seems more accurate, it shows high core temps but only a gradually warming CPU temp.

[ryuk999]

What is says in your bios is what the temp of the cores are. Not all programs that are built to record cpu temps are accurate, however if you want a reliable program I use it's called H/W monitor by CPUID. It measures more than cpu temps and fan speeds too.

[Hufigyed]

Core Temp reads from the sensors in each core, that's why if you have a quad core, you'll see 4 readings. The bios receives it's info from either the sensor on the die or sometimes under the CPU (not physically in the CPU).

Thus Core Temp gets the temperature closest to where heat is generated which is in the core(s). With Intel CPUs I'd definitely go with either Core Temp or Real Temp as the most accurate (compared to bios)

I have an i7 860 and I used to go by the bios temp and more than once the CPU shut off to protect itself from overheating, thats what the code was on the BSOD. I couldn't figure out why, bios never reported temperatures higher than high 60s so obviously it was reporting too low. Then I got Core Temp and Real Temp and noticed I had temperatures in the high 90s. (Big Yikes!)