A.Purchase a 4-way p630 to compensate for not using SMT.
B.Purchase the p5-550 server and install AIX 5.2, which can be upgraded to AIX 5.3 later.
C.Purchase the p5-550 server and install AIX 5.2 and enable SMT.
D.Suspend the purchase of a new machine at this time and upgrade the current server to a 4-way server.