MicroATX Mobo that can Underclock a C2D

[JMecc]

I need a board with BIOS options to underclock a C2D for low heat dissipation. I want to have onboard video and no moving parts – the CPU and anything else requiring cooling heatpiped to a thick aluminum case and the hard drive will be a solid-state one. I’ve take a quick look around and have found these boards:

Asus P5K-VM
Gigabyte GA-G33M-S2

Can anyone using these boards confirm to me that there are bios options allowing underclocking of the FSB in reasonably small increments?
Any other boards you would recommend for underclocking a C2D?

Edit: Also, will getting a faster cpu (E6750) and underclocking it to a lower speed (equivalent to the E2140) make it run cooler than the already low-clocked E2140 or will they generate the same amount of heat?

Thanks,
Jo

 

[roadrunner197069]

Buy the 2140 and leave it stock. Either way you are gonna need a fan for the CPU. If you want quiet go for the e2140 and spend the rest of the cash on a water cooler. The radiator will still have a fan though.

Im pretty sure if you dont have a cpu fan plugged in the system wont even power on.

 

[Mondoman]

You might be able to get the 2140 to run OK with a heat sink but no fan. You should be able to disable any CPU-fan-speed-monitoring setting in the BIOS. You might have to hook up a fan the first time to allow you to get into the BIOS, but it wouldn't even have to be physically attached to the CPU heat sink.

However, you may very well find that the PWM circuitry and the north and south bridges heat up too much without any fan-assisted airflow inside the case.

 

[JMecc]

I'd likely hook up heat pipes to the north & south bridges too and anything else that gets hot. There are all-in-one industrial computers that run fanless on a 1.2GHz Via processor by just hooking up a heatpipe to the rear of the case, which is a big heat sink. I figured an underclocked/undervolted C2D would perform better (+ with more DDR2 ram and better integrated video) I could have a decent pc without moving parts.

I'll experiment when I get parts but I still need help determining which to buy for my tests.

Jo

 

[Mondoman]

The industrial computers presumably have been designed for fanless operation; an off-the-shelf consumer MB may very well work, but I would certainly try to maximize openings for convective airflow cooling. Before messing around with heatpipes, just see what the temps are with the normal heat sinks and convective cooling -- that might be plenty.

 

[JMecc]

I figured that the industrial computer would have many provisions for fanless operation, but I recently took one apart to find that the motherboard is close to the backside of the LCD and right beside the power supply. Although the backside is a heat sink, the only component touching that is the CPU (via one heatpipe with blocks on its ends).

I'll try with the stock heatsink and the fan unpluggged to see what happens in the undervolt situation.

Thanks,
Jo

 

[Mondoman]

Sounds good. Of course, in Edmonton all you would need is a tiny hole in the wall to get all the supercooled air you wanted. :lol:

 

[randomizer]

You don't need to be able to drop the FSB, you just need to be able to lower the CPU multi, and the vcore especially

 

[JMecc]

Is the CPU multi & vcore dropping a standard feature even on microATX boards?
Jo

 

[gufz]

there's a zalman case that's prety much like that

 

[randomizer]

Is the CPU multi & vcore dropping a standard feature even on microATX boards?
Jo

Not sure, it depends how cheap the board is. Budget boards often don't have those options.

 

[JMecc]

Yeah that's the thing like randomizer says, budget boards don't have these options, but what is budget; would $130-$140 boards like the Asus P5K-VM and the Gigabyte GA-G33M-S2 have clocking and voltage options, or do I have to go to $180 boards?
Jo

 

[Onus]

My Gigabyte GA-G33M-DSR2 has those options; I'm going to guess the -S2 has them as well, but I'm too slack to dl a manual right now. Its Northbridge does get a little warm though, so I do have front and rear low speed fans going. They are pretty quiet; the stock fan on my 7900GS is louder, but you won't have that.
The Gigabyte boards have Intel GMA decellerators though; you might look at some of the BioStars that have ATI integrated graphics.