Hmm, yeah, good point. I was running HAWX last night for the first time in a while, and in DX10 mode I did have to turn something down to get it smooth...all of turning the AA down to 4x instead of 8x....wait a minute....I don't think I paused BOINC ...I'll have to test that again tonight..
EDIT:
Tried it again yesterday, and with BOINC paused I cranked it up to 8x AA without any problems.....and then I realized that I still had Oblivion running in the background So, yeah, at least at 1680x1050, no worries with the GTX260.