B550
B550
Which board are we talking about? I can help you identify it and explain how to handle it later.
The B550 chipset came out after the 3700X, so it can handle it. But what about your previous board and why you’re upgrading? Changing the motherboard rarely makes sense, particularly with an AM4 socket. Or if you purchased that chip now, why did you choose it over the 5600/5600X? Those Ryzen 5000 models are usually more affordable and offer better performance across most tasks.
The 3070 chip fits in a PCI Gen 3 port (though the 3000 series might not support it, you could consider upgrading the CPU).
I don’t think there’s much to upgrade here. This board isn’t outstanding, but it should suffice for now. Spending $150 on a new motherboard makes more sense saving it for a bigger upgrade later—whether it’s AM5, RTX 40, RX 7000, 13th gen Intel, etc., or simply more games. You won’t gain much performance from a board upgrade unless you’re running at maximum power limits (which isn’t likely here) or if you need a specific feature that the current setup lacks. Unless there’s something you really need, it makes no sense to rush. If you’re just upgrading for fun, consider waiting a few months for next-gen CPUs and boards to become available. Knowing exactly what’s missing would help.
Upgrading your stock cooler from 3700x to a 240mm AIO paired with your PSU could work. This setup is suitable for future upgrades like the AMD 7,5800X or 5,5600X.
You could try it, but it's not essential. A 5600 would be a solid improvement, though only if you manage to buy it at a reasonable cost or require extra single-thread speed. I still agree with my earlier point—if you're upgrading simply because your system isn't meeting your needs, and you're satisfied with its current performance, give it a couple of months. Then next-gen features will appear, making the upgrade worthwhile.