Thinking out loud: more flexible fan control in BIOS

Control: management of fans, temp/rpm monitoring via soft/hardware

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theycallmebruce
Posts: 292
Joined: Sat Jul 14, 2007 10:11 am
Location: Perth, Western Australia

Thinking out loud: more flexible fan control in BIOS

Post by theycallmebruce » Mon May 03, 2010 6:29 pm

This is just me brainstorming a little. Apologies for the length.

Fan control is, of course, very important in silent PC design. On this forum, almost every aspect and method of fan control must have been discussed.

Broadly speaking, the flexibility of fan control solutions seem to roughly match the complexity and amount of effort required. For example, installing a rheostat in line with a fan is dead simple, but may require manual adjustment under high loads. A complex, dedicated fan controller board including temperature sensors may allow great flexibility, but could be expensive and fiddly to install and set up.

I'm a big fan of software control for ultimate flexibility. It seems to me that all modern systems have the hardware built in to let this happen, without adding extra fan control hardware. The missing link is the BIOS.

As far as I know, the software control options at present using the motherboard sensors and control circuitry are:

1) Rely on the built in capabilities of the BIOS. Depending on the board, this may be adequate, but is generally quite limited. You can't set specific temperature thresholds, fan speeds etc.

2) Use third party software. I don't have much experience with these, and I'm sure some of them are excellent, but my problem with them is that they all seem to rely on an operating system to be loaded. This can be an issue if you multi-boot. It also means you need something else to control the fans until the OS has booted (I know, a nitpick).

Imagine if there was a flexible way to modify fan control in the BIOS. At the moment, the only way I imagine this could be done would be to reverse engineer the BIOS. I imagine this would be very difficult. Also, changes would be limited to a single BIOS, and would have to be redone for new BIOS revisions.

The ultimate would be to have the source code for the BIOS. I know, I'm dreaming. A close second would be a standard API in the BIOS providing access to the sensors and control lines, so you could compile your own fan control modules and link against the BIOS. Again, I'm dreaming.

Even just a much more flexible fan control interface in the BIOS provided by the factory would be nice. For example, allow users to supply a lookup table of fan speeds versus temperatures for each fan.

Has anybody done anything along these lines?

ascl
Posts: 279
Joined: Tue May 05, 2009 1:15 am
Location: Sydney, Australia

Post by ascl » Mon May 03, 2010 8:58 pm

Some motherboards allow exactly what you describe, ie adjusting the bios controlled thresholds.

Alternatively, you can purchase a seperate controller, like an Aquaero, which you program via software but it has its own controller, so once its configured doesn't rely on the OS to be running.

theycallmebruce
Posts: 292
Joined: Sat Jul 14, 2007 10:11 am
Location: Perth, Western Australia

Post by theycallmebruce » Mon May 03, 2010 9:23 pm

Thanks for the reply!

Which motherboards allow you to do this? I haven't seen this in any of mine (all Gigabyte boards), but maybe I'm just not looking hard enough.

The Aquaero certainly looks like a very nice product. In particular I like the fact that you can add flow sensors.

However I would prefer not to have to use any additional third party controller because:
1) I would rather have access to the internal temperature reading from a CPU/GPU than an external probe.
2) It just seems a shame that you need to duplicate hardware because of a lack of software flexibility in the BIOS.

ascl
Posts: 279
Joined: Tue May 05, 2009 1:15 am
Location: Sydney, Australia

Post by ascl » Mon May 03, 2010 9:26 pm

Gigabyte are the ones I have experience with recently... my last ASUS board had terrible fan control! hah, but I am sure they have improved.

Check out EasyTune, specifically the Smart Fan section:
http://www.gigabyte.com.tw/FileList/New ... PX_ET5.htm

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