Motherboard to underclock (undervolt) my Athlon...

[kilmanjaro]

I need some help from you guys on a recomendation for a motherboard that would support undervolting a 1.3 ghz Athlon. I'm looking for something relatively cheap but it has to be very stable. The reason that I need this is because I've got a computer set up to be a TIVO/MP3 Player/Emulator/etc. The problem is that it runs too hot for my comfort level in the room. I'd need to be able to undervolt (and underclock) the cpu. I have an Epox 8k7a that I'm using right now. I love the board and it lets me underclock but it doesn't have the option to undervolt. No integrated features are needed, I've already got video/NIC/sound cards. Anyways, any recommendations as to a good/cheap/stable board would be appreciated.

 

[Evadman]

You can mod the voltage bridges to get the voltage down to 1.5v. Frankly, I would just pickup a cheap morgan core duron (1.0 to 1.3 variety ) and sell the athlon to recoup the $$ spent.

Toms hardware has the matrix on the voltage settings.

 

[kilmanjaro]

So even though the default voltage on the Morgan is still 1.75, it is just a cooler cpu? I'm just not sure on the specifics here. As I'm looking at the thermal output I'm almost convinced to sell the board too and go with a cheap celeron setup. Thermal output on it is about half (60W Duron/35W Celeron/75W Athlon). Crap now I'm confused about what to do . Anyways, thanks for any help you guys can offer.

Edit: Just realized the board I've got for my p3 setup (Gigabyte GA-6OXT) supports Tualatin CPU's. Guess that makes up my mind, spend $60 on a Tualatin and have fast and quiet.

 

[keyeye]

Bump for an answer. I'm interested in the KT3 Ultra2, and want to get one of the $55 1600+ chips. But I'd like to undervolt / underclock most of the time as I spend most of the time in non-CPU intensive tasks?

I know the KT3 has voltage mods, but undervolting?

 

[eclectro]

I really doubt that "undervolting" a CPU will make it run significantly cooler. The Athlon CPUs will run hot no matter what you do.

 

[keyeye]

Depends how fast you run them. What sparked my interest was the Athlon SFF. 100mhz FSB, and much lower voltage. Palomino core, but otherwise don't know that much about them. Not available in the US as far as I know.
Athlon SFF

Undervolting link
I really only need about a 1 - 1.2ghz athlon. According to the undervolting link, they took a 1ghz tbird at 49 watts to 19 watts by undervolting and reducing the speed to 700 mhz. I assume that is what they did with the athlon SFF.

Anyone have a KT333 board that offers sign undervolting?

 

[Insane3D]

The latest KT333 board from Epox, the 8K5A2+ has CPU Vcore settings down to 1.2v or so IIRC. Epox's site is down at the moment, so I can't check for sure. I was just helping a buddy out with his system, and the bios screen for that board had a ton of CPU Vcore settings.

 

[Insane3D]

Ok, I checked Epox's site for the 8K5A2+ manual, and found it here. According to the manual, it allows for a Vcore from 1.4v - 2.2v.

 

[keyeye]

Thanks alot for your help, Insane.

I did find out from a relative who just built one with the MSI KT3 Ultra2, that it doesn't allow much undervolting. only 1.7V or so for a 1.75V CPU.
He did like the board alot, though.

I think I'm going to get the 8K5A2+. Seems like the 15 bucks for the (+) is worth it for the USB header and lan. May/may not use the Raid.

 

[Insane3D]

Thanks alot for your help, Insane.

No problem...glad I could help.

I think I'm going to get the 8K5A2+. Seems like the 15 bucks for the (+) is worth it for the USB header and lan. May/may not use the Raid.

I agree. The extra $15 is worth it IMO for the onboard LAN alone...a decent NIC will run you near that anyway. The RAID and nicer sound is just a side benefit.

 

[joe4324]

I'm willing to bet that your power supply is dumping more heat into the air then your proc, maybe you should look there as well.

 

[wurmyhi]

Nice note also, Joe...

I have a number of boxes, and on my main one, I'm starting to plug/unplug drives due to heat from the hard drives. While it may seem cumbersome, it really does make a noticable heat & noise difference.

 

[keyeye]

Interesting thought, Joe. I'm aware of higher efficiency power supplies (i think Zalman touts them, and I think PFC is also supposed to be higher efficiency), but I've never seen anyone really do a study on how that affects system temp. If you have any info on this, I'd be interested.

I do know that the heat output of a PS is somewhat proportional to the watts it puts out (I think most PS are somewhere around 70% efficient, correct me if I'm wrong), so lowering the output of the PS will decrease its heat output.
Secondly, the heat output of the PS is right in the exhaust path, so it shouldn't affect system temp (though system temp will affect PS temp and possibly decrease the lifespan of the PS).

As for unplugging drives, wurm, that's a little far out. Cumbersome seems a little understated.