So I ran a couple of benchmarks with my g3420 and GTX 750. Only at 720p as that's what my tv runs at.
Bioshock Infinte at the ultra preset.
Scene Duration (seconds), Average FPS, Min FPS, Max FPS, Scene Name
32.47, 76.80, 14.91, 406.96, Welcome Center
7.08, 72.32, 11.88, 416.17, Scene Change: Disregard Performance In This Section
21.72, 84.68, 42.73, 448.81, Town Center
8.11, 76.74, 5.74, 120.76, Raffle
9.08, 122.06, 29.51, 481.07, Monument Island
3.52, 135.88, 116.90, 153.73, Benchmark Finished: Disregard Performance In This Section
81.97, 86.08, 5.74, 481.07, Overall
Batman Arkham Origins
Benchmark run: 05/03/14 12:19:06
Min = 55.71 Max = 218.91 Avg = 125.12
FullScreen: YES
Resolution: 1280X720
V-Sync: OFF
Anti-Aliasing: OFF
Geometry Detail: DX11 Enhanced
Dynamic Shadows: DX11 Enhanced
Motion Blur: ON
Depth Of Field: Normal
Distortion: ON
Lens Flares: ON
Light Shafts: ON
Reflections: ON
Ambient Occlusion: OFF
Hardware Accelerated PhysX: Normal
Clearly some headroom to bump up the graphics in places as well. I also reckon 1080p would be pretty doable.