Hi all. Am considering upgrading to Quad as I plan to do video work and 3D digital art. At the moment I have AMD Dual core 4000+. My first question is would it be worth just upgrading to a faster dual core (max is 5800+ on my mboard)? Next, are Intels better than Athlons at the moment? My PSU is a 450W Corsair. Would this be ok for a Quad system? And is DDR2 ram ok for a quad system? Thanks.