First Thing First... Let’s see how fast our Processor can go.
Set your Memory Divider at its lowest setting. (Usually 100 or 133) This will give us a LOT of headroom to push out CPU.
Next, Drop your HTT Multiplier to 3x and your CPU Multiplier 1 Notch (If you have a 2 GHz CPU, drop your Multiplier down to 9x)
with these settings most AMD systems will boot and run at a 230HTT so go there first. Once you get into Windows, Run a 1Million run of SuperPi, and then a Prim95 Max heat test for about 10 Minutes. If it passes both of those, its time to go further.
Go 5 MHz at a Time and Repeat. During this we'll want to raise the VCore of our Processor to maintain stability. Once SuperPi and/or Prime95 fail, raise your VCore .05 Volts and Try again. SEE CPU Voltages Ademdum at the end of this guide for processor specific Voltage recomendations.
This is a Slow Time Consuming process, so have a few Mountain Dews and some chocolate bars handy.
Once your push your HTT bus back over 800 MHz (267HTT Bus) raise your Chipset Voltage up to 1.7
with any luck, you'll hit 260-280HTT Depending on your CPU.
Write this info down and then we move on to testing out Memory.
CPU TEMPS ADDDENDUM
As stated above, A64s are VERY efficient, there have been reports of outrageous overclocks using the stock AMD Heatsink. But I would still recommend a high quality Swiftech or Thermalright Unit. (Dee DavidHammocks HSF Guide for specifics)
Anyway, Standard Desktop chips should be kept under 55c in ALL cases. It should NOT be hard to keep then under 45-48c with good quality cooling. Running higher than that is a good indication that you have misapplied your HSF and/or AS-5 Remount.
Mobile chips are rated a bit higher, but there is still no reason to ever see temps higher than 55c. The lack of an IHS provides better contact with the Heatsink and it’s very possible to keep temps at 45 and lower with quality cooling. Even with high overclocks.
Torture your Memory Next
Memory is usually the Culprit in holding back overclocks. Finding out the capabilities of what our memory can do is critical.
Drop your HTT bus back down to 200, and reset your Memory Divider to 1:1 (Usually "AUTO") Leave your CPU Multiplier at 9x (For a 10 Stock Multi) and let start out at 215 at Stock Timings, Bump VDimm up to 2.7v(Or +.1Volt)
The 2 tests you want to do here are SuperPi 1 Million and Memtest86 You'll need a Floppy disc or Bootable CD to run Memtest86 (Or if you have a DFI UT, there is a Modded BIOS available with Memtest built in)
Run 5 Passes of Memtest86, then boot into Windows and Run SuperPi. You won’t be fast, but SuperPi 1Million runs a LOT of numbers through your Memory. If all goes well, go up 5 MHz at a time until one starts to error.
That’s where we need to start loosening the timings.
Go up .5 on Cast Latency, 1 on RAS to CAS Delay, 1 on RAS Precharge, and 2 on Cycle Time (Tras) and Repeat these tests. Depending on your memory,
you may want to loosen them more, but I would suggest keeping them under 3-4-4-11 if at all possible. If you’re using Memory Other than TCCD based, don’t be afraid to bump your Memory voltage more. Most modules will take 2.9-3.0 Volts just fine and BH-5 has been known to go as high as 3.3 to 3.5v!
Once you've found your Memory’s max speed, this is where we need to do some math. Most likely there’s a sizeable gap between what your CPU can do and what your Memory can do. That’s OK.... That’s why we went down a Notch or 2 on our CPU Multiplier testing.
Lets say your CPU went to 260 Stable with a 1x drop in your Multi, Not bad.... a 340Mhz O/C on a stock 2Ghz chip... but your memory only went to 230 before you had to go to slow in your Timings. That’s OK.... Drop the HTT down to 230 and bring your Multiplier back to stock speed (10 xs in our example) you should have a Rock Solid 300Mhz overclock on your hands.
If the Gap between your Memory and CPU is so high, you can’t get to your Max CPU Speed with your Stock Multiplier, we may need to run a higher Divider on our Memory.
If we're talking 30+ MHz base difference.... You should probably drop your Memory Divider down to 166 and use your Max CPU Speed we figured out. Less than 30 MHz and you'll probably get better performance running 1:1 at your Memory speed. I say this because we'll be losing memory speed at our best settings at that point. Only use a Higher Divider IF your CPU speed will bring your Memory speed to within 2-5 MHz of your MAX Memory Speed. 240HTT X10 = 2400Mhz, Divided By 11 (166) brings out Memory down to 218Mhz If out MAX speed as 236, we're Giving away Memory bandwidth for no reason. However, if your Max CPU bus is 260, then we get this 260x10 = 2600 /11 = 236.
See how that works? Now out Memory is maxed AND out CPU is maxed....