According to sandra the multiplier on the motherboard on my a7v8x-x and xp 2200 1.8GHz has no effect uppwards even if the changes is visible in the bios.
Frequency overclocking of the xp 2200 1.8GHz cpu by 15% to 2.1GHz worked and system is now stable without the need to change the core voltage and cpu and motherboard temprature is unchanged compared to the level before overclocking-cpu 44 degrees celsius-motherboard 37 degrees celsius.
System is stable and i think the story ends here with the fact that i am satisfied with my 2.1GHz XP 2200.
Bench-test shows it has a performance of a xp 2800 at 2.1 GHz and memory runs nice at 333+overclocking but i use ddr 400MHz rams.

Thanks