INFO: Abit KR7A(-R) Optimal Bios settings
 

As far as the KR7A is concerned here are a few tips that worked for me. These settings are what I use for maxed performance.

SoftMenu III-

CPU Speed: User Define
FSB: Your choice
Ratio: 4:2:1
Speed Error Hold: Disabled

Voltages: As you see fit. I recommend you start with 2.75 DDR voltage to overclock.

CPU Command Decode: This is an important setting! For <150FSB set to Ultra, 150-200FSB set to Fast (using Ultra above 150 or so can cause stability issues...Your Mileage May Vary)

Advanced Chipset Features Setup-

System Hole, System BIOS and Video RAM: All Disabled

DRAM Clock/Drive Control-

DRAM Clock: 133MHz (do not set to SPD if overclocking)
DRAM Timings: Manual
DRAM CAS Latency: 2
Bank Interleave: 4-way
Precharge to Active: 2T
Active to Precharge: 5T (6T is more stable only if needed)
Active to CMD: 2T
DRAM Command Rate: Another important setting! Use 1T at 133 to 150 or so, 2T at higher FSB speed. 1T will limit your overclock so experiment with it. I have found that you'll get better overall performance by using 2T and running a higher overclock)

AGP and P2P Bridge Control

AGP Aperture Size: 128M (smaller of 128 or 1/2 of RAM)
AGP Mode: 4x (works fine to 200FSB for me)
AGP Driving Control: Auto (works fine for me)
Fast Write, Read Master and Write Master: All disabled (for max stability)

CPU and PCI bus control-

Default settings fine

If using 2 sticks of memory try using DIMMs 2 and 4 (works better for many users when overclocking).

Hope that helps!

Thx Jmke, this one helped a lot.