a typical for gigabyte mobos.

there is a 10k pull up resistors for fsb. by some reason clock gen chip can't see logic 1 over time.
i ended up replacing 10k resistors with 1k ones.

Well, I'm not sure what to conclude since this different CPU is working at 233MHz and there have been no issues.

Have you tried measuring the FSB of the motherboard directly with each CPU installed?

I've never tried doing that before. What do I need to do that?

You mentioned you have an oscilloscope, right?

I would look at probing both the CLK pin for the main CPU socket (you'll want to likely trace where that pin is going since there might be a test point on the board somewhere).

You could also probe what the ICS9148 chip is doing. According to the data sheet, speeds are controlled via the FS0, FS1 and FS2 pins.

The way I would test this is running through every FSB setting combination on the motherboard with both processors. At the same time, I would measure what is happening on the board including the ICS9148 chip. By documenting everything with all possible combinations you should be able to get an idea of what is actually happening on the motherboard.

I would just press the mobo with a finger while running any benchmark with live reading like Landmark