GTA V running at Low Framerate

[xkevs21]

When GTA V starts, everything's all fine and dandy, not great, only 25 fps tops, but playable. After about 10 minutes, things stop rendering for a while and the fps drops to about 15, making it mostly unplayable, since i can't see where I'm going. Another 10 minutes and the rendering issue is gone, and FPS is about the same, but every 10 seconds there would be a tiny lag spike, like 1 second. This continues for about 20 minutes, progressively getting longer and more frequent. After that, the game is basically unplayable, you would hit A to avoid something and 5 seconds later you turn. Only by then, you're already halfway across the map, upside-down in a ditch, car on fire. I am playing off of a Seagate Expansion 2TB hard drive on windows 10, through UEFI on mac.
Mac Specs:
MacBook Air (13-inch, 2017)
Processor 1.8 GHz Intel Core i5
Memory 8 GB 1600 MHz DDR3
Graphics Intel HD Graphics 6000 1536 MB

My settings on GTA V are, for the most part, turned all the way down. Do I need more RAM? Better processor? Better graphics? Another hard drive? Or is my mac just too under-powered and I need a desktop?

 

[gamerk316]

While the CPU is an i5, it's VERY low clocked, and that is going to hurt in GTA as it tends to be a bit more of a CPU hog then other titles. The integrated HD Graphics aren't going to help matters either. The RAM should be fine though.

The root issue is you have a weak CPU combined with a weak GPU. I don't see how you'll get GTA running nicely on a laptop with specs like that.

 

[beegmouse]

Agree with above, with some additions.

The decrease in performance over time will be temperature related.
Laptops, have poor cooling, thinner ones even more so. The CPUs are generally fine for running at max power for a minute or two, but then have to slow down to protect themselves from overheating. Then when cool enough, it will speed up again.

Your performance will never be great, it's not a gaming machine. But for improvements, keep the laptop cool, on a hard ventilated surface, not laps or duvets etc. Move the game files to the internal drive, it will likely be faster than the external one.