I'm upgrading my system and am in the process of selecting a new PSU that will adequately take care of my current needs while leaving me some headroom for future upgrades, all at a reasonable price. One thing that has been confusing me as I look at the available units is how there are now models with three 12v rails as opposed to just two. What I am wondering is if there is any particular advantage to getting a model with three 12v rails over one with only two. I am not building an sli system, nor will I in the future. With going three rails give me more upgradeability in the future? All things being equal, is three better than two? Here are the two main PSU's I'm looking at: http://www.newegg.com/Product/Product.asp?Item=N82E16817103457 http://www.newegg.com/Product/Product.asp?Item=N82E16817103939 Here's what my final build will be, I'm not planning on doing any overclocking, just regular work and some game playing. Will either of these two PSUs be enough power? and if not, what wattage should I be shooting at? Athlon64 3000+ Zalman 7000alcu hsf Asus A8N5X mobo 2x1gb Corsair XMS pc3200 2xSeagate Barracuda 7200.7 120gb sata (raid0) xfx geforce 7900gt Soundblaster Audigy 2 ZS Antec Sonata Also, should the A on the 12v rails be the main priority? I mean, if one PSU has 32 at 3.3, 32 at 5, and 18 on the two 12v, is that better or worse by comparison to a PSU with 26 at 3.3, 28 at 5, and 20 on each 12? Thanks!