The M4A89TD PRO/USB3 has the typical ASUS AMI BIOS; the overclocking page is named AI Tweaker (unlike the enthusiast level boards which have the Extreme Tweaker). However, that does not take away from the functionality of the AI Tweaker. You still get many of the same options found on the Republic of Gamers boards.
Inside the AI Tweaker you find a couple of important pages that deal with memory timings and drive numbers. These provide you with a multitude of options to get the best performance and stability from your memory and the IMC on your AMD CPU.
Under the Advanced tab there are some additional pages that, while not as important as the AI Tweaker settings, can help you with stability if you are having issues on that end.
On the CPU Configuration page you can also enable the ASUS Core Unlocker as well as disable cores on your CPU individually. This setting is one that I am not sure is useful. After all, if I buy a quad core or a sexa core, why would I want to turn CPU cores off? True, with AMD CPUs there are times when a single core will fail an OC while the rest pass, but turning off a core will still cause more performance loss than it is worth in most cases.
The DRAM controller page has the usual options that are available to AMD CPUs.
Onboard devices configuration needs no extra explanation.
In the power section of the BIOS we found some odd settings. There was a list of voltages that at first we thought were only a display. It turns out they are limits in some way. The VCore was set to 1.416 and was preventing higher settings regardless of what was set in the AI Tweaker page. This setting was preventing our Phenom II X6 from getting over the 250MHz mark until we changed it to "Ignore". Also present on this page is ASUS' Q-Fan options; these are great if you are looking for the best combination of cooling and noise reduction.
Although ASUS makes some excellent overclocking motherboards, this one was hindered by the AMD CPU we used. The Phenom II X6 1090T we have as a test CPU has yet to allow us to push it over 4.1GHz with any type of stability. Once we hit the 250MHz mark for the bus we began to have some pretty frustrating stability issues. We were able to run roughly half of our tests without crashing to the desktop or rebooting. That was until we found a small setting in the BIOS that was limiting the CPU voltage to 1.416.
After we told the system to ignore this voltage, the voltages evened out and we were able to find stability at 250MHz x 16 for around 4GHz CPU speed. At 251MHz things went south again rapidly, so we need to do some additional tweaking to get past this limit.
You can see the validation for the ASUS M4A89TD PRO/USB3 here.
The ASUS TurboV EVO software is simple and clean. It gives you everything you need to overclock your CPU from inside Windows with the exception of the ability to adjust the RAM speed. The look of the software is nice with a sleek look. ASUS has dropped options for almost everyone from the beginner to the more advanced user.
There is even an option to let the system do things for you. We checked this option out and found the board, all on its own, was able to give us 3.9GHz which is not bad at all.
Once you have an overclock that you like, you can save that as a profile and associate it with your TurboKey option. This allows you to enable that OC with a key combination on the fly without the need to even open up the TurboV EVO software.
As all overclocking results are dependent on the hardware you use, your results may vary. Results of our overclocking tests are included in the performance section with the stock scores.
Important Editor Note: Our maximum overclocking result is the best result we managed in our limited time of testing the motherboard. Due to time constraints we weren't able to tweak the motherboard to the absolute maximum and find the highest possible FSB, as this could take days to find properly. We do however spend at least a few hours overclocking every motherboard to try and find the highest possible overclock in that time frame. You may or may not be able to overclock higher if you spend more time tweaking or as new BIOS updates are released. "Burn-in" time might also come into play if you believe in that.