CrossFire X has a few other nice attributes that SLI doesn't share. One of those is the ability to work seamlessly with multiple monitors—no more enabling and disabling multi-GPU mode in order to switch between single-screen gaming and multi-display productivity sessions. AMD says this capability has been extended to more than two GPUs. Even four GPUs and eight displays ought to work effortlessly, as I understand it, though I've not had the chance to try it out myself. The one drawback here is that 3D apps running in a window are only accelerated by a single GPU.