I am working on getting a parts list for a new computer I am building and I would like some opinions on whether I should go with 1 Nvidia GTX 280 or 2 1gb 9800GT's running in SLI.
preferably neither, if you're serious about performance get the Radeon HD4870X2, it's significantly faster than either.
You don't need an nvidia card just because you have an nvidia board. I tend not to advise people to buy nvidia chipset boards because in my opinion (and not just my opinion) they're rubbish, but since you've bought one that's that I suppose.
i have not purchased anything yet that was the barebones i was looking at I am trying to stay between 1200 and 1400 dollars. do you have any suggestions on where to purchase a system or the parts in that range.
You're better off building the PC yourself if you're knowledgable enough to start with a barebone. Post in the SPEC-ME or official PC Building thread.
