A recent increase in performance issues and hardware demand in the PC version of GTA V has been linked to just-released DLC. Known for being a visual masterpiece, GTA V's final port was always notoriously needy on the higher settings, though the mid range was well enough optimized that it could run smoothly on most machines. Modding also added a new factor into the equation, with both graphics enhancing mods which upped the requirements, or performance improving mods, which occasionally achieved their results at the price of worse visuals.
Even so, GTA V had a bit of a bumpy road on PC. There was a time when hackers and modders in GTA Online got so bad that Rockstar opted for the rather extreme solution of cluttering up the game files with heaps of dead code. They succeeded in making modding no longer viable both in single player and in Online, however they also accidentally made the game a tad broken.
However when that was fixed, the troubles of the PC players weren't over. A large portion of PC gamers have rigs running AMD graphics cards. Despite being generally weaker than their nVidia counterparts, AMD cards have the massive advantage of a balanced price-value ratio. While nVidia GPUs are a bit stronger, they're more than a bit pricier. You'll be able to run mostly the same settings with a high-end AMD card as a high-end GeForce, at a smaller price.
You might imagine then how big of an issue graphical bugs that only affected AMD cards were. AMD even put fixing GTA V compatibility on the top of their list of yearly goals. Efforts are still underway.
