Archer
Honorary Master
The issue with any multiple GPU setup with the LGA1156 / 1155 platforms is that you only have x8 bandwidth going to the cards, instead of full x16. On the top end cards like HD5870 / GTX470 and up this results in a ±5% drop. That performance hit is usually only at 2500x1600 and up though. Faster cards will obviously have larger performance drops. But currently the absolute worst case scenario is 10% drop.