9800 GTX+ and GTX 560 Ti

[candleboy8]

Currently, I am running a 9800GTX+ with a Phenom II x3 720, 4GB DDR3, and an Ultra LSP550 PSU. I run two monitors from the 9800. I want to add a GTX 560 Ti and another monitor. Will the LSP550 be able to handle both cards or will I need a serious upgrade? It has 550-watts and 30amps (12v).

Also, when I put the 560 in, does it matter what PCIe slot it goes in? My board is a MSI NF750-G55. It says both slots are x16, but x8 when in SLI. Since I wont be using SLI, they should both run x16, correct?

 

[Mousemonkey]

It will probably drop down to x8 if both slots are populated.