CPU fan speed control

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Intel_Hydralisk

Supreme [H]ardness
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Feb 6, 2005
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Just installed a Cooler Master Geminii S into my rig. @ stock the load temps went down by a whopping 20 C (70->50), so I felt comfortable enough to OC now.

Managed to hit 3.77 ghz with my i7-860 but the fan was whirling real hard (very loud...), so I decided to back down to a nice 3.4 ghz.

The problem is that the fan speed seems to be incredibly inconsistent. The motherboard (MSI P55-GD65) has a smart fan control option in the BIOS. By default, it's off. Here's a summary of how it behaves:

Smart fan control OFF: When windows boots, the CPU fan is incredibly fast and loud. After a few minutes, it dies down and becomes almost inaudible. Temps during this time are 30-35C. When I run prime95, the CPU fan doesn't actually ramp up, it remains at the same inaudible speed. Load temps reach ~65C @ 3.4 ghz.

Smart fan control ON: It doesn't actually matter what the settings are for this in terms of what happens, but say for example I set it to 65 C target temp and 50% fan speed min. The fan will spin up very fast and loud when windows boots then dies down after a few minutes (same as before). It doesn't ramp up when I run prime95. It WILL randomly ramp up when I'm idling on the desktop for no reason. It'll randomly ramp up and become very loud when idling in the 30's.

From a pure temperature standpoint, there really aren't any issues since it loads at ~65C @ 3.4 ghz no matter what. However, what bothers me is the odd behavior of the fan. I don't want to be met with a giant wind turbine-like sound when I boot into windows. I also don't like random ramp ups in speed when idling. If it actually ramped up under load (which it doesn't right now), perhaps I could see even lower temperatures at load.

EDIT: I'm using speedfan now which works flawlessly. However, I'm still curious why the BIOS smart fan controller seems to fail... they pretty much do the same thing correct?
 
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The bios could be poorly scripted or in some way or has conflicts the fan. Sounds like it only has a Too Hot and Ok profiles. Glad to hear speedfan worked though.
 
Intel_Hydralisk said:
Just installed a Cooler Master Geminii S into my rig. @ stock the load temps went down by a whopping 20 C (70->50), so I felt comfortable enough to OC now.

Managed to hit 3.77 ghz with my i7-860 but the fan was whirling real hard (very loud...), so I decided to back down to a nice 3.4 ghz.

The problem is that the fan speed seems to be incredibly inconsistent. The motherboard (MSI P55-GD65) has a smart fan control option in the BIOS. By default, it's off. Here's a summary of how it behaves:

Smart fan control OFF: When windows boots, the CPU fan is incredibly fast and loud. After a few minutes, it dies down and becomes almost inaudible. Temps during this time are 30-35C. When I run prime95, the CPU fan doesn't actually ramp up, it remains at the same inaudible speed. Load temps reach ~65C @ 3.4 ghz.

Smart fan control ON: It doesn't actually matter what the settings are for this in terms of what happens, but say for example I set it to 65 C target temp and 50% fan speed min. The fan will spin up very fast and loud when windows boots then dies down after a few minutes (same as before). It doesn't ramp up when I run prime95. It WILL randomly ramp up when I'm idling on the desktop for no reason. It'll randomly ramp up and become very loud when idling in the 30's.

From a pure temperature standpoint, there really aren't any issues since it loads at ~65C @ 3.4 ghz no matter what. However, what bothers me is the odd behavior of the fan. I don't want to be met with a giant wind turbine-like sound when I boot into windows. I also don't like random ramp ups in speed when idling. If it actually ramped up under load (which it doesn't right now), perhaps I could see even lower temperatures at load.

EDIT: I'm using speedfan now which works flawlessly. However, I'm still curious why the BIOS smart fan controller seems to fail... they pretty much do the same thing correct?
Click to expand...

Almost the same exact thing happens to me.. the fan will not ramp up when the processor gets hot. what is up MSI?
 
Best thing is to get on MSI's tech support forum or ticket system whatever and complain or it will never get fixed. They (as far as I know) dont have anyone here monitoring the forums, at least not in the open.
 
Alright I figured out why the BIOS smartfan controller won't ramp up fan speed as the cores get loaded (and hot). The input into the feedback controller is not using any of the core temperatures, but instead uses a 5th temperature (chip temperature? - I don't even know what to call it). It's that *other* temperature that always seems to max out in the 40's.

So as a result, I have to set the target temperature to 40 C since at full load that temperature never goes above 43-45 C (I checked it in speedfan). With target at 40 C... as soon as my cores enter the 60's, this temperature hits the 40's and my fan speed will ramp up when smartfan controller is on in BIOS. Unfortunately 40 C is the LOWEST target temp possible in the BIOS. It goes from 40-70C.

Anyway, the end result is that setting target temp in BIOS to 40C and minimum fan speed to 50% (or whatever you want) works best for me right now so I don't have to rely on windows software to control my fan. Although, speedfan is a great tool.
 
Interesting, typically board have two built in thermistors one in the well of the socket under the cpu and one someplace on the board for a "system" temp.

Pretty strange the cpu fan header would use the system temp thermistor. Maybe they dont have a cpu socket thermistor.

Still some weird stuff, I think someone at MSI's bios still messed up. Glad you figured it out and thanks for letting us know.
 
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