Opera: (3)The FX-55 is the cadillac of the Clawhammer core chips (The Opteron is the 'Sledgehammer'); it has the biggest internal cache's, a dual memory controller I believe, instead of the single controller that the Athlon 64 has, so you have some serious memory bandwidth to play with. But frankly, the standard Athlon 64 (and better to get the socket 939 version...that way you can upgrade to the dual core chips when they are available) is more than sufficient. While Poser isn't a 64 bit app, in many ways that doesn't matter. The Athlon 64Opteron runs 32 bit code in a native mode; no emulator is needed. The actual pipeline in the chip is quite a bit shorter than the one in Intel's flagship product...which is one big reason AMD chips do as much or nearly as much as an Intel chip clocked 30-50% faster (put it this way; when DEC was broken up by HP, many of their better minds were shopped by AMD. When the Alpha chip was torpedoed, AMD got another infusion of talent that designed one of the best architectures out there). Once XP-64 is out, even if the app itself doesn't use the expanded addressing, the OS will, which will have an impact on the swap file, and the amount of base memory available. Or at least it should. We are talking Microsoft, after all....