According to the Intel PC100/PC133 specification sheet, the left hand notch in buffered pcb card is off center 1/16" from "centered" between the card edge signal traces, supposedly preventing them from being used in non-server type motherboards. People have posted here that they have inserted buffered ram in "consumer" mobo. Since there are several hundred mobo's, who knows. Buffered ram shouldn't install or if forced in, boot on your mobo.