I have a Thoroughbred 2400+ (133*15, currently running on 166*12). I would like to put it on 200*10 but the system wont boot up. I think the prob is in bios advanced/advanced chip features, cpu interface = optimal, it should be cpu interface = aggressive, but its grayed out and i dont know how to ungray it and set it to aggressive.

"cpu interface = optimal, it should be cpu interface = aggressive" Wrong. Try this: CPU Ext Freq = 200MHz CPU Freq multi = 10.0x System Performance = User Defined CPU Interface = Optimal Memory Freq = 100% *** (see note) Memory Timing = User Defined SDRAM Active Precharge Delay = 11 SDRAM RAS to CAS Delay = 3 SDRAM RAS Precharge Delay = 3 SDRAM CAS Latency = 2.5 FSB Spread Spectrum = disabled AGP Spread Spectrum = disabled CPU Vcore setting = Menu CPU Vcore = 1.65v Graphic Aperture Size = 128MB AGP Freq = 67MHz NOTE: I'm assuming you have DDR400 (PC3200) RAM. If you have DDR333 (PC2700), set the Memory Freq to either 83% or "By SPD". However, if you use "By SPD", the SDRAM timings will be ghosted out.

nothing :(, again it wont boot up. yes i have DDR400. I tried 200*11 and boots but in win i see artifacts after some time (since original clock is 2000mhz), so if this works i assume there should be way theat 200*10 works too.

Try increasing the CPU voltage a little...maybe 1.70v?

it wont boot up again. i tried 1.70v, 1.75v, 1.85v but nothing. theat cpu interface still bugs me, is there any way to change it?

I had one of those boards for a couple of years & had no probs...those are basically the settings I used. You do NOT need the CPU setting at aggressive. For the heck of it, try a lower CPU multi setting like 9.0x & see what happens.

9.5x and everything lower, and 11.0x - 15.0x works. Maybe my Thoroughbred cant work in 200*10, but i saw people sad it works