Ok, I'm looking into water cooling for my computer. It's a dual opteron workstation with a 6800GT I 've been hearing that the DD TDX is supposed to be a really good CPU block. I went to the DD site and noticed that they have the TDX in pure silver as well as copper. So I was wondering, is it really worth more than twice the price of the copper block? I'm also not going to be overclocking, because you can't exactly OC Opterons (to my knowledge). Another question that comes to my mind is, would the water be too warm to sufficiently cool my 6800GT after it goes through two CPU blocks?