When it comes to overclocking the SL-KT600-R mainboard, there is good news and bad news.
To begin with the good news, there is a very well equipped BIOS to handle the mundane chores of overclocking. You have the ability to adjust voltages to the processor core, the AGP port and the memory slots. Core voltages range from 1.1v - 1.85v and can be adjusted in 0.025v increments. AGP adjustments allow for changes from 1.5v - 1.8v and can be made in 0.1v increments. DIMM voltages range from 2.5v - 2.8v and are also adjusted in 0.1v increments. None of these values are made for extreme overclocking, but they will allow you a very wide range of settings to get a very workable system speed.
FSB settings are also made within the BIOS and allows adjustments to be made in small 1MHz increments. There is also full control of memory timings to include settings for latency and interleave settings. This will help you get the best performance possible from whatever type of memory you are using.
Finally, there is an optional BIOS add-on called RedStorm Overclocking. While it isn't really of a lot of use for the hardcore enthusiast, it can be a great help to younger members of the overclocking community. What it does is to run tests internally on different FSB settings while you're still in the BIOS. From there it will determine what the highest FSB setting is that it can run perfectly stable. It then reboots the system and you get the benefit of this new setting. I found that it is very conservative on the result it uses, but it does manage to give you a good starting point to use in your overclocking endeavors.
And now for the bad news...
Once upon a time there was the KT333 chipset. When using this chipset, you had to physically unlock the processor to gain the benefit of multiplier manipulation. But then there was born the KT400. Lo and behold, it allowed you to magically adjust the multiplier of any Thoroughbred or higher made AMD processor. Life was good, but then somebody decided to remove this ability within the KT600 chipset. Don't ask me why, but if you decide to use this variety of chipset, you will be destined to overclock by means of FSB only unless you are wanting to physically unlock your processor. And lets be honest, why would we want to do this when the KT400 and the nForce2 chipsets will still allow you to bypass the multiplier lock on these newer processors? It seems to me as though VIA has taken a step backwards.
Also of note is that you cannot lock the AGP speeds when overclocking. This means that you will be running your video board and peripherals well out of spec when you crank up the FSB settings. This can very possibly limit your maximum system speeds.