About two-card

The formation of Crossfire or SLI graphics cards, like this time each pcie turned into 8x bandwidth, and not every pcie original 16x, so half the bandwidth, graphics performance will not have it halved?

performance will not be halved.just more than half the bandwidth.But you raise the speed of computing! Therefore, only a little loss of performance.Generally 1.5-1.8 times the single card