Re: My motherboard currently have
Well, it will throttle iself. It's going to reduce the speed, so that the PC125 stick will work. If you select in your BIOS to use PC133, you will lose your PC125, as it will not be used, due to the lack of speed.
DJ-CRHIS, I don't know about PC-142, but I know that there is something higher than it. I don't remember which one though.