I have the Abit AV8 3rd Eye. Just like all mobo's now, inorder to OC. You have to get to know how the mobo works. For one, the RAM speed is locked. Most mobo's let you change its value from the start. I havent tryed nor figured how to unlock it. Second its Windows Overclocking Guru Utility, dont OC on, you NEED to OC in the bios. OC through windows will invite a crash.
In the bios you can press F8 to OC in the instant. Dont get lazy and do this, because your computer needs to restart with its changed settings. So press F10= save to bios and restart. This mobo offers great Temp monitoring and Fan controling, very handie to have as a OC. It also lets you set high temp and low temp alarms. You can change the temp, and set it to beep or restart once your custom limit has been reached.
You can also Save stable OC settings. On your Windows Guru Utility, you have something that says Normal/Quiet/User1/User2/User3. You can save an OC configuration, then set it to one of those options. Then you can simply click the User1 button, and the settings turn on instantly. Beware, OC through your bios. If your system is stable at that configuration. Then go to your Windows Guru Utility, and set those OC configurations up, then save it.
Second, in your Bios, it has your External Clock. This is what you OC with obviously. Click it, then change its value to Fixed 66mhz. You wont be able to OC much if your AGP ratio is not fixed.