Check this out, some guy made a pretty cool video showing the Batman benchmark with PhysX and all settings to high on his Eyefinity setup.
http://www.gamephys.com/2009/12/03/ati-eyefinity-physx-batman-arkham-asylum-benchmark-run/
http://www.gamephys.com/2009/12/03/ati-eyefinity-physx-batman-arkham-asylum-benchmark-run/