Xeon X7542, 2666MHz, FCLGA1567, 130W
As you know, the Xeon Foster is called "Willamette with SMP support", and the Xeon Prestonia is known as "Northwood with SMP support". These CPUs are based on the same core. Besides, the pairs of "Foster - Willamette" and "Prestonia - Northwood" are based on the same fabrication process and have the same L2 cache size. The processors have different sockets, but if you look at the signal assignment diagram the pins of the Socket 603 processor will show that most of them control either power supply or ground, i.e. they are not significant.
IBM Xeon X7542, Intel® Xeon® 7000 Sequence, 2.666 GHz, LGA 1567 (Socket LS), Server/workstation, 45 nm, X7542
IBM Xeon X7542. Processor family: Intel® Xeon® 7000 Sequence, Processor frequency: 2.666 GHz, Processor socket: LGA 1567 (Socket LS). Thermal Design Power (TDP): 130 W, VID Voltage Range: 0.675 - 1.35 V. Intel® Virtualization Technology (Intel® VT): VT-x