Help overclocking AMD Barton 2800+

System
AMD Barton Athlon XP 2800+
Gigabyte cooler for CPU
Abit AN7
2X512 Corsair DDR400

I try to overclock and to obtain from FSB 166x12,5 to FSB 180x11,5 with memory timings default and it becomes very unstable,after that i raise the Vcore to 1.73(step by step) and memory Voltage, the same (memory errors or buting problems)
should i raise de Voltage to Northbridge to?
I want to reach a higher FSB without lowering the memory frequency and stable.
Which settings ar better to have
FSB 170x12 and the memory at frequency 333 with 2.2.2.6(actual)
or
FSB 180or200 x10/11 and the memory frequency 400 and 2,5.4.4.8 or higher timings

I believe that processor is multiplier-locked. The only way to O'C it is to raise the FSB. :?

First drop your memory timings way down cas 3. Set a divider too 2:1 (or something very low), so that your ram isn't limiting your OC. See how high you can get the FSB. Watch your temps. Take note.

Then go back to a 1:1 divider with a stock FSB and tight timings. Raise the FSB slowly untill it gets unstable. Take note.

Now you should have your chip's (or your MoBo's) highest speed and your rams limits.

Play with settings in between. Depending on what you are doing, folding or playing games, you may end up happier with a 200 fsb a 5:4 memory divider and cas3.

The XP-Ms were all unlocked. They fit standard socket A, low stock vCore and great OC's. You can still find them on eBay.

If it's unlocked and your board supports it, drop your multiplier and run at 200 FSB.
Try 200 x 9.5 to start.

Not all of them. I was lucky enough to get a barton that was unlocked.

I guess I was lucky too! I bought the slowest Barton for ~$75.00 I rasied the clock to 200-202MHz w/ 10.5 multiplier and I'm running ~2100MHz . My memory is at 333MHz 2-3-3-7 on an Abit A7N.

So not all Barton's are unlocked? What's the deal with that?

-AM