Is an Arc B580 and PSU upgrade worth it with my Ryzen 5 5600G build?

For a new card in this price range, the B580 is a reasonable choice. I would replace the current PSU with a reputable model before installing it, rather than relying only on the wattage rating. Also check that your BIOS has Resizable BAR enabled and that the system is using the latest motherboard BIOS and graphics drivers. The 5600G can remain in place for now; a CPU or platform upgrade can wait until you have a larger budget.

Keeping the 5600G and putting the budget toward the graphics card and a better-quality PSU makes sense. The B580 may be somewhat limited by the 5600G at 1080p, especially in CPU-heavy games, but it should still provide a substantial upgrade from the A380. If you’re open to buying used, a Radeon RX 6700 XT is another option worth checking out: it has 12GB of VRAM, a full x16 interface, and generally mature drivers.

The B580 will work, but your A520 motherboard and Ryzen 5 5600G only support PCIe 3.0. Since the B580 uses an x8 interface, it will run with less bandwidth than intended. Make sure Resizable BAR is enabled in the BIOS, because Intel Arc cards can lose noticeable performance without it. The card should still be a major improvement over the A380, just not necessarily as fast as benchmark results from newer platforms.