I need some single VS triple monitor benchmarks

[PC User]

Hey, I built my first gaming PC only a few days ago and bought a T500 RS and raceroom rr1000 cockpit last year so I'm almost ready to start sim racing. But I need the last part, the monitor. I used to use my living room's 42" TV to play Driveclub and I loved that game but wanted to move to more realistic sim experience so I finished building my medium budget PC a few days ago and downloaded a pirated version of Assetto Corsa to see if I like it. After I first tried this game I got blown away by how amazing this game is but I won't buy it now, I'll buy it after I complete building my setup. I have a Radeon HD 7850 with a G3258 processor and after overclocking I'm running everything on High and getting about 60 to 100 FPS depending on the amount of AI. So I'm thinking of buying another used 7850 for $80 from ebay and then save some money to have a triple 27" 1080 monitor or a single 42" but not sure if two 7850 could handle triple monitor setup. So I'm estimating if I get 60 FPS now, after I crossfire I'll be getting at least 90 FPS right? Then if I run 3 monitors would I at least get 30 FPS (90/3=30)? If you run triple setups, what FPS do you get on single vs triple? Your benchmarks should give me a good idea. Thanks.

 

[Stereo]

I get around 60-65 triple, 120 single on my 760GTX. My CPU's the limiter on the single screen fps though, so it drops off a bunch with more AI (since they use a fair amount of cpu)