I've got 2 CPUs here, with the following markings: UltraSPARC IIIi D5126772 0535 PG3.4 980 USA SME 1603A uPGA 1170-1503 AC4 Any idea what these are? My guess would be 1.503GHz, which would explain why they don't work in this motherboard. (Which is a 375-3226).