I would
definitely recommend the RX 6600 for your son based on all the factors involved and I'll explain why:
List of Factors:
- Your son's CPU is an R3-4300
- Your son's PSU is a Corsair 450W CV Series
- Your son is currently using a GeForce 710
- Your budget is <$400
From what I've seen, someone here is recommending the RTX 4060, a card that would make absolutely no sense at all because there are so many cards that would be better for your son. Most are reds but there are a couple of greens that I would recommend over the RTX 4060. I'm going to ignore them because, ultimately, the RX 6600 is the best card for your son. I'll compare it to the RTX 4060 (which will be an
easy win) to demonstrate why the RX 6600 is the best choice.
The RTX 4060 is
27% faster than the RX 6600, which is definitely nothing to sneeze at. It's a pretty big difference. However, the RTX 4060 is 57% more expensive than the RX 6600 which makes it a bad value unless your son's use-case demands something as potent as the RTX 4060 (in which case the RX 6600 XT, RX 7600 or RTX 3060 Ti would be better choices, in that order).
Here are the current lowest prices for both the RX 6600 and RTX 4060 according to PCPartPicker:
ASRock Radeon RX 6600 Challenger D 8GB - $185 at Newegg
PNY GeForce VERTO RTX 4060 8GB - $290 at B&H
Power consumption isn't an issue here because while the RX 6600 does indeed draw more power than the RTX 4060, from what I've been able to find, the difference never exceeds 10W which is completely insignificant.
When it comes to the performance difference between the RX 6600 and the RTX 4060, I seriously doubt that your son would notice the difference. Let's be honest here, if he's currently using something like a GeForce 710, it's a safe bet that he's gaming at a resolution no higher than 1080p (maybe even lower than that) and that the games he plays are not hardware-intensive. Compared to the GeForce 710,
anything would be a massive upgrade and the RX 6600 wouldn't be bottlenecked by your son's R3-4300 like the RTX 4060 would.
It's a pretty easy win for the RX 6600 and the best part is that you can bank the $205 that you didn't spend today. In a generation or two, that $205 you didn't spend will get you a GPU that is
superior to the RTX 4060 so you'll be ahead in the end anyway.