bon voila c'est une vielle comparaisons
http://www.hardwareheaven.com/reviews/1062/pg5/nvidia-gtx-580-oc-vs-radeon-6870-oc-crossfire-vs-radeon-5970-bad-company-2.html
les drivers amd
sont de mieux en mieux optimisé crossfire
By now you’re probably wondering how the Preview Driver stacks up against our most recent release, AMD Catalyst™ 11.2. We raised our baseline image quality in 11.2, so the performance improvements going to the 11.4 Preview should be pretty small, right? Wrong. Based on various configurations, resolutions and settings, our internal data still shows pretty amazing improvements!
Up to 23% performance improvement in Aliens vs. Predator
Up to 22% performance improvement in Batman: Arkham Asylum
Up to 15% performance improvement in Battleforge
Up to 72% performance improvement in Civilization V
Up to 59% performance improvement in Call of Duty: Black Ops
Up to 26% performance improvement in FarCry 2
Up to 35% performance improvement in Lost Planet 2
Up to 30% performance improvement in Metro 2033
Up to 11% performance improvement in S.T.A.L.K.E.R.: Call of Pripyat
Up to 19% performance improvement in Chronicles of Riddick: Assault on Dark Athena