TS500-E4/PX4 SAS Tower Server - 2 x Socket LGA771, FSB 667/1066/1333MHz EM64T 2x2M, 4M or 8M L2 cache, 6 x Dual Channel FBD 533/667, max. 16GB (B3 Stepping)/ 24GB (G1 Stepping), 1 x PCI-E X16 (x 8 link), 1 x PCI-E X8 (x 4 link), 3 x 64bit/133/100MHz PCI-X, 1 x 32bit/33MHz PCI