What GPU Should I Upgrade to for My Old Gaming Rig?

You can keep your RAM, PSU, case, and monitors, but you might want to replace your CPU and GPU. I suggest going for the 14600K plus a 5060; that's the best combo for your situation!

Consider getting an RX 6800. It's a solid card and should work well with your setup.

If you're eyeing GPUs like the 9060 XT 16GB or even the 9070 XT, you’ll need to upgrade your CPU to prevent bottlenecks. Your current Z270 motherboard only supports up to 7th gen Intel, so a new motherboard is a must. I’d say go for a 12th or 14th gen Intel CPU with a DDR4 board. The LGA1700 platform is great because it allows for future DDR5 upgrades without needing a new CPU. In your shoes, I’d grab a secondhand i5 14600K or an i7 14700K with a DDR4 LGA1700 motherboard. And don't worry, your 850W PSU is adequate.

You might definitely want to think about upgrading your CPU too. I’d recommend switching to an AM4 system with something like a Ryzen 5 5600. The RX 7800 XT is solid, but depending on your location, it could be pricey or even hard to find. If it goes over $520, I’d skip it. Check out AMD’s newer cards—the RX 9070 around $550-$600 is excellent, and the RX 9060 XT with 16GB is a great bang for your buck at about $400-$450. If you grab any of the higher-end options, definitely upgrade your CPU to either a 5700X or 5800X to avoid any bottlenecking.