im not sure about which motherboard would be best... but if you want to avoid increasing the cpu temperature by much at all, you should use the lowest cpu voltages you can (and still be able to remain stable)... you should be able to get about 2.7 on even your current MB without much of a cpu voltage increase at all (assuming you can increase voltages with it), all you really need to do is reduce your memory speed, while relaxing the latencies (increasing memory voltages a bit if needed), and reduce the HTT multiplier down to 3X
those few things should go a long way in being able to increase your cpu speed, and still maintain a decent temperature... and you have standard stability checking too, running orthos for awhile to see if you have any problems
download amds dashboard demo from their site to monitor cpu temperatures (its the most accurate cpu temperature monitoring software ive used), and try to stay below 71C as that is the rated cpu threshold(assuming your cpu is 90nm), stay below 60C if you can help it, and any lower than that is nice, but not 100% necessary (i try to stay below 58C personally)
its not good to jump all the way to 2.7 right away though either, you should do it in smaller increments, till you find a stable speed (and temperature) that youre comfortable with
also make sure your case has good enough airflow too, because no matter which motherboard you have, overall temperatures are going to be much higher than they should be if you dont have proper case airflow
not sure a bios update would help, that does suck though... but, heres a list of motherboards at frys.com... the listed manufacturers are pretty well known: DFI, Asus, ECS, MSI, Abit, and Gigabyte. you can look over which motherboards offer what features youre interested in. AFAIK they all should overclock, even my budget ECS nforce4-a939 gets my X2 3800+ up to 2.73 (it ran kinda hot at that speed, considering the voltage boost that was needed, but even still)
I have a similar setup with the exact same motherboard. I was able to get a 9%OC on it using NVidia Ntune. Only thing I did was increase the HTT to 217, everything else stock. Simple and easy. You may want to upgrade the RAM to pc2-5300 (I tried G.Skill pc2-6400 but not stable at the stock 1.8V though rated 1.8-2.0V) This may increase performance.
I've been thinking of replacing the Mobo like you, but a couple things have stopped me.
1. $$$ Cost of new mobo + cpu cooler(currently 32C idle 51C load on stock hsf and extra case fans)
2. The OEM Windows would no longer work since activation is bios dependent.
I have a X2-4400+ oc'd to 2.6 and I noticed an increase in temps going up from the 2.2... I'm not saying it's a bad idea... I'm not even saying it will be difficult... I'm just saying you're being unrealistic if you don't expect a rise in temps. At best your temps may remain constant at idle, but under load you will see an increase... count on it.
Sry for the double post but how can Ntune increase bios setting being a windows run program?
Does that actually work and I thought that ntune was a graphics card OC'er and not a processor OC'er.
If it can do that then maybe that's worth a try!
Ntune has sections for overclocking both motherboards and graphics cards. But since this motherboard's bios has no overclocking options, most of the software overclocking options in Ntune are disabled. However, you can increase the HTT and HT multiplier and change RAM timings. And as for temperatures, I wouldn't want to overclock this anymore even if I could, without an after market hsf. It is at 51C load with this OC and stock hsf.