I tried several GPUs and tested them mainly with Gamecube (Mario Kart Double Dash!!):
Radeon HD 7750 (CPU Pentium G3220) - System very slow, even Main Menu is extremely slow... unusable
Radeon HD 6310 (CPU AMD E350) - Slowdowns even with native resolution, not really usable
nVidia ION GeForce 9400 (CPU Celeron SU2300) - Slowdowns even with native resolution, not really usable
Nvidia GeForce GTX750 (CPU Pentium G3220) - Slowdowns even with native resolution, not really usable
Intel HD Graphics 2000 (Pentium G630) - runs ok with some minor slowdowns here and there at native resolution. With higher resolution than 1.5x you get massive slowdowns
Intel HD Graphics 2500 (CPU Celeron 1037U) - runs ok with some minor slowdowns here and there at native resolution. With higher resolution than 1.5x you get massive slowdowns
Intel HD Graphics 2500 (Pentium G1610T) - runs good and almost 100% smoothly at native resolution (slowdowns only at presentation ceremony). With higher resolution (1.5x ore more) you get massive slowdowns
Intel HD Graphics GT1 (CPU Pentium G3220) - runs good and smoothly at native resolution, higher resolution (1.5x or more) you get slowdowns
Intel HD Graphics 4000 (CPU Core i5-3427U) - runs good and smoothly at native resolution, higher resolution (1.5x ore more) you get slowdowns
Intel HD Graphics 4600 (CPU i7-4770T) - runs very good. Resolution up to 720p (2x native) runs smoothly (but with higher resolution you get some slowdowns)
Intel HD Graphics 5000 (CPU Core i5-4250U) - runs very good. Resolution up to 720p (2x native) runs smoothly (but with higher resolution you get some slowdowns)
Intel HD Graphics 515 (CPU Core m7-6Y75) - runs good and smoothly at native resolution and almost 100% smoothly at 1.5x resolution. With higher resolution than 1.5x you get slowdowns
Intel HD Graphics 530 (CPU Pentium G4500) - runs very good, even with 2.5x native resolution (1600x1320) smoothly (with 1080p you get some slowdowns)