Its a good combination for medium detail gaming, but don't have enough information to help you further. It would help if you provided Motherboard name, specs, power supply, and budget.
As far as frames it won't be close, most games that won't unplayable will now become playable with a preformance increase of 300%. I have seen gtx 760 go for 190. If the 190 is just for the video card.
G620 is too outdated and will bottleneck 760. So I would go with i3 and 750 as gaming preformance is very reliant on both. Ideally, you could get both, but if I have exceed is because I thought you meant 190 for just video card.
Okay sick! Can you tell me how to update BIOS? I just downloaded the BIOS to support Ivybridge CPUs but when I ran the application it said not compatible with 64bit system but that's the only download on their site.
H61MXL-K Support Ivy Bridge CPU BB5F1P01 4.41MB 3/26/2012 - This download?
Have a look in the manual(same website as the bios) on how to update the BIOS specific to your mobo. I'll try download the manual as well but I'm on a chromebook right now.