At the end of the day we saw an overall performance increase of 63% when going from a single GeForce GTX 680 Surround to a 2-way SLI Surround multi-monitor setup from the seven game titles we tested. This is a nice performance gain and it did make for an overall better gaming experience at a resolution of 5760x1080..."
Any major computer upgrade generally requires a full software reinstall too. No so if you heed the advice in the guide to Upgrading a Motherboard without Reinstalling. PCSTATS Tips