This CrossFireX configuration earns 9/10 from KitGuru.
"For most of us the AMD HD6990 is a pipe dream, the cost is very hard to justify. Let’s not forget that unless you are gaming at super high resolution or across multiple screens it is often not needed. With the recent release of nVidia’s GTX550 ti, AMD have decided to update their popular HD5770, with the new HD6790 targeting the £120 sector. Today we are looking at the custom Sapphire HD6790 model which features an enhanced heatpipe cooler and PCB design."