What is your budget?
What is your current graphics card?
You want to make a biggish jump to be satisfied.
Best to not use vram or gddr type as a selection criteria.
Usage is different between nvidia and amd drivers.
In general, the vram you get will be appropriate for the card.
FX-4100 has a very weak core speed; I would speculate that something like a GTX1050ti would be the strongest card you could usefully use if your games are fast action shooters.
Less if you play sims, strategy or mmo games.