Confused by my systems temps.

[way2fast91]

I recently upgraded to an AMD 7750, Asus mobo, and 4GB OCZ Reaper. In my old case with 2 poorly placed 80mm exhaust fans and stock hsf, the system temps according to PC Probe II were:

Idle: Cpu - 45c, MoBo - 40c
Load: Cpu - 50c, MoBo - 45c

So yesterday I moved the setup into an Antec Nine Hundred case (2 x 120mm intake, 1 x 120mm and 1 x 200mm exhaust fans), replaced the stock hsf with a CM TX-2 with Arctic Silver 5, and installed a psu with a 120mm exhaust fan of it's own. This is were I need some input from others. According to PC Probe II last night, systems temps were:

Idle: Cpu - 31c, MoBo - 53c
Load: Cpu - 38c, MoBo - 54c

Maybe one of the fans is blowing straight onto the MoBo temp gauge? Is this normal? I accomplished what I wanted as far as cooling the Cpu, I was hoping to get under 39c, so that I could then try pushing it to 3.0 Ghz minimum without getting over the previous temps. But now I am a little comcerned that the MoBo is running too hot. Thoughts?

 

[zagood]

One of the problems I've always had with the new generation of "mesh" cases like the 900 and the CM 690 is that there isn't any real control over airflow. What normally ends up happening is that the components with their own fans (CPU, GPU, etc) will be cooler with more access to fresh air - however anything that's passively cooled will be warmer. You'll see similar results in an open-air setup.

You can try either a) adding a fan to your northbridge, b) closing up the excess vents in the front grill, side panel and anywhere there isn't a fan, or c) not worrying about it.

Also if you're overclocking, check your NB voltages and set them to stock and see if that helps.

IMO, since the mobo temp doesn't rise dramatically under load you should be ok. If you need to bump your NB voltage to get your overclock however, you may run into problems.

-z

 

[way2fast91]

Is there a default temp or range maybe that I wouldn't want to exceed under any circumstances on the MoBo? A threshold that should not be crossed? 60c, 70c? Obviously the cooler the better, but at what temp should I become concerned and do something about it. PC Probe II had the default alarm set on the MoBo to 45c, I upped it to 55c.

Ambient temps in the room are ~23c

Edit: Also, I am not oc'ing yet, but the cpu has unlocked multi and I was hoping to adjust that. I assume that would push the Cpu temp higher, but shouldn't effect the NB temp correct?

 

[way2fast91]

Last night observed temps as:

Idle: Cpu - 31c, MoBo - 48c
Load: Cpu - 38c, MoBo - 54c

I am seeing a bit of a difference in MoBo temps now between Idle and Load. I am going to probably try increasing the clock multiplier to get to 3.0 Ghz this weekend and will report back on my temps. Still looking for answers to the questions above. Thanks.

 

[BonzaiDuck]

Originally posted by: way2fast91
Last night observed temps as:

Idle: Cpu - 31c, MoBo - 48c
Load: Cpu - 38c, MoBo - 54c

I am seeing a bit of a difference in MoBo temps now between Idle and Load. I am going to probably try increasing the clock multiplier to get to 3.0 Ghz this weekend and will report back on my temps. Still looking for answers to the questions above. Thanks.

On motherboards I've had -- typically for INtel processors -- the motherboard sensor is not located at the northbridge, but closer to the Mosfets that surround the CPU.

Personally, I think your "mobo" temperature is a little high. To my experience, idle temperatures have seldom exceeded the low 30's C at room-ambients between 70 and 80F.

You could try ducting the motherboard with foam-art-board panels to channel intake air through a narrow space between the mobo and foam-board, so that the air is then drawn immediately out of the case by an exhaust fan. It's tedious, takes a little time and precise management, and may not be worth the trouble. But it works.

 

[way2fast91]

Thanks for the info BD, if the sensor is in fact near the mosfets / CPU, it may be that the (stupid) downdraft plastic shield is actually venting hot air from my CPU cooler (CM hyper TX2) down onto the MoBo sensor. I will open 'er up this weekend and do some testing of this theory. Although I can't imagine that air coming off the heatsink of a component running at 31c-38c being blown onto a sensor would register at 50c+, but stranger things have happened. I think I remember someone who had my cpu cooler talking about removing the plastic downdraft shield. Without it, air would blow through the heatsink and straight out the rear exhaust fan.

I love the ducting idea for channeling air across the MoBo. If I can't figure anything else out, I may just be crazy enough to try that.