I have GTA5 and I get roughly 60 fps maxed out at 1024x768, and around 48 fps average max out at 1080p. Cuz of my CPU I hit 39 fps sometimes driving through the city at 1080p, 44 fps sometimes at the 1024 res but its rare, definitely not all the time, fairly rare. If I had an i5, it would be ~55 fps at all times.
The minute I turn off hyperthreading on my i3 to effectively make it a Pentium, GTA5 cannot run beyond 40 fps and it dips into the 28 fps levels. That's just for anyone who thinks they can cheap out and buy the overclockable Pentium. Worst decision you will ever make