New PSU, new GPU, computer is louder.

Yep, PSU is pretty good. Board is fairly good too, for the chipset it has. Probably the best board out of that specific chipset although you'd be in a lot better shape with a 990fx chipset board IF you are going to stay with that AM3+ platform.

What is your current CPU model, because to be honest there isn't much, if anything, I'd recommend paying to upgrade to on that generation that would be worth your while unless you can get it for a VERY reasonable price. Don't even THINK about the FX-9370 or 9590, you will have nothing but problems and heartache, plus you will have simply thrown your money away, going with those. You would also need a very high end motherboard. Your board would NEVER support it. Even the highest end boards BARELY do. Sometimes they actually DON'T, at least not without a lot of VRM throttling going on.

Might also consider that as most AM3 boards, regardless of chipset, get older, they DO tend to almost universally suffer from VRM throttling due to electrical fatigue except on boards with really good power phase and component selection.

And for gaming, going from even something like the FX-4300 to the FX-8350 probably isn't worth the investment either because you will not be gaining much. Same four primary cores, basically, and there are some differences but for all intents and purposes it's much like adding four hyperthreads to the four main cores as they used shared resources. So, if something is REALLY well optimized for multiple threads you'll see some improvement.

For most games that rely on four or less strong cores to see performance gains, you'll not see a lot. Overclocking what you currently have, which will be possible on your board if you have a 4 or 6 core FX chip, not recommend with ANY 8 core FX chip on that board, would probably offer you the most gains but you would also need a capable aftermarket cooler.

All told, not worth the overall investment as by the time you got done buying an FX 8 core chip, new overclockable motherboard and CPU cooler you could have been well on your way, or into, something much newer that would still greatly outperform it.

Certainly there are options and I'm not saying there is no way to gain some performance without a platform upgrade, I just think it's worth thinking about whether or not what you will gain is worth the investment versus what you will gain by upgrading the whole platform and whether the long term investment potential of a full core component upgrade might be a lot wiser move even if you have to wait a bit longer in order to do it.

There is no other FX CPU you can upgrade to from the FX-8300 that would be worth the investment. Unless you have a very poor piece of silicone, you should be able to overclock that CPU to FX-8350 performance levels with a decent cooler and motherboard.

However, your motherboard is NOT suitable for an 8 core FX processor. Thermals and power phase are good enough for a four or six core processor from the Piledriver family but not for an FX8 chip. I'd be surprised if you were not experiencing VRM throttling and other thermal issues on that board with that CPU. Any money you put into that platform at this time would simply be throwing good money after bad.

As for the DDR3 on an LGA1151 board, uh uh. DDR3L ONLY, and even that is not recommended as we've seen too many systems experience premature motherboard failure despite the fact that those early Skylake systems were supposed to be compatible with it. I would not support the intent to try that.

You would be FAR better off limping along with what you have for now, until you can scrape together enough for a newer platform.

Practically anything from the AMD Ryzen family with 4/8 (Or more) or any Intel platform from Skylake on will perform well with your GPU card. The performance of Coffee Lake is much better than Kaby or Sky Lake though, and honestly the very best bang for the buck CPU right now seems to be the i5-8400.

On paper it looks weak with only a 2.8Ghz base clock, but every review shows it being within a few fps of the top i7-8700k for gaming AND testing behavior shows that when there is ANY load at all, it's very hard to get that CPU to run at anything below 3.6Ghz, so the base clock speed is really a non-factor as it runs basically at 3.6Ghz anytime you are doing anything, has a Turbo clock speed of 4Ghz, comes with six physical cores and no hyperthreads (So no SHARED resources to speak of for thread performance) and has an ALL core max Turbo of 3.8Ghz.

I think this is the best option BUT even a Coffee Lake i3 has four cores, making it as good as or better (Since there have been some IPC and clock speed improvements) than the past three or four generations of Intel i5 SKUs.