I run a pair of gtx 460s in SLI and for me when I ran it in dx11 mode, maxed out, and it lags out horribly. Put it in dx9 and the most you can set it on is "medium" gfx detail, and I stay in triple digit FPS and SLI working fine.
Kinda pissed about the dx11. That was supposed to just be a problem with the demo
Here is what I posted in the Bioware forums after doing some quick tests on various dx11 only settings:
dx11 mode (this is just quick plays to test settings, not extended play time)
--all runs have v-sync off--
1) medium setting, 4x AA, --- generally stays above 90 fps
2) high setting, 4x AA, no ambient occ.---mostly 80+ fps
3) high setting, 4x AA, amb. occ. on ---mostly 60+ fps
4) high setting, 4x AA, 4x AF, amb. occ. on ---pretty much low 50s into the 70s for fps
5) very high setting- nothing else on --- lags out, unplayable.
This is not so much a complaint, but more of a report of early findings. The game early on at least plays great and looks great for me using the above #4 settings.
I would think that there should not be such a huge drop in performance from #4 to #5 though. From great to unplayable with one setting.