MB temp higher then CPU's?

[rowcroft]

I've got a dual XEON system and have it running in a Sonata case- swiftech heatsinks and vantec 80mm stealths using the TT duct mod. The procs run at 35C but the mobo temp is 40C I have the one 120mm fan exhausting and replaced the PSU with an Antec 550w (think it actually runs quieter!). I understand that generally speaking, the mobo temp should be lower then the CPU temp- any ideas on why it's the opposite here? I have a theory but would like to hear from you guys as well. Thanks!

Rowcroft

 

[huesmann]

MY theory is that you have your sensors switched bass-ackward.

 

[rowcroft]

That'd be rather difficult to do with a dual cpu setup. This is using Asus's PC Probe software and also through the bios. Thare aren't any physical cables that I could have plugged in the wrong place-

Rowcroft

 

[yruffostsif]

First guess would be that there's a ton of hot air blowing off those heatsinks hitting that board sensor. I'm not sure where it is, but the last asus board i owned, it was in a stupid place.

Second, combine the first with some cable or memory obstruction and no front intake fan...you can see where I'm going.

How 'bout the exhaust fan, is that the remote sensor fan? where's the sensor? Does it actually work?

 

[boyRacer]

I'm guessing the sensor is near the northbridge or something... my old Abit had an abnormally high system temp too... and the bigger fan i put on the CPU HS the more it heats up... probably because all the heat is getting dumped near it.

 

[rowcroft]

Makes sense, I'm not going to worry about it too much, since everything is within reasonable limits. Love the Sonata case though!

Rowcroft

 

[WobbleWobble]

My girlfriend's P4 2.6C runs at 27C while the mobo temp is 29C. I found that interesting as well

 

[beverage]

Originally posted by: rowcroft
I have a theory but would like to hear from you guys as well. Thanks!

Rowcroft

what was your theory?

 

[rowcroft]

My theory was with the lower airflow and the duct mods on the heatsinks that less airflow to the mobo is being generated by the hs fans. It's directed now and the 120mm in the Sonata case exhausts it pretty efficiently. That with the increase is airflow through the 5.25 bays that other Sonata owners have reported, I think there is less air movement in some parts of the case. I imagine if I installed the second 120mm fan it would decrease the mobo temp somewhat, but wouldn't have much impact on the cpu temps.

Rowcroft