To start, x8 vs x16. Depending on the video card, x8 will cripple your video card by about 5%, so not much to worry about. I also wouldnt plan to get 2 video cards, its generally better to just get 1 more powerful one, and upgrade it. IE, instead of getting 2 5770s, get 1 5870, then upgrade to a 6870 or 7870. Basically, all that is saying people get a lot more worked up over x8 than they should, especially if you are only buying 1 card. Onto 890FX vs 790FX. They are very similar. 890FX natively supports the new 6 cores, whereas 790FX will likely need a BIOS update. 890FX also more natively supports USB 3.0 and SATA 6, such as most 8xx boards have those, where as most 7xx boards dont. Thats about it. However considering you are getting a 6 core, and the 8xx series costs $10 more than the 8xx series, id go with a good 8xx board. Although what system will you be using? You might want to go with a 870 board.