I'm upgrading my girlfriend's PC and want to improve it without replacing the entire system. It currently has a Ryzen 5 1600, an AB350M motherboard, 16GB of DDR4-2666 memory, and a GTX 750 Ti 4GB. The 750 Ti has handled games like Valorant surprisingly well, but it is clearly due for an upgrade. I'm considering an RX 7600 XT 16GB because it would be a huge improvement and the extra VRAM could help with her design work. However, I'm worried the Ryzen 5 1600 would hold back a modern GPU. Would it make more sense to install the GPU first and upgrade the processor later, or should I buy a cheaper graphics card and upgrade both components together? I'm trying to keep costs reasonable and want to know whether a GPU upgrade alone would make the system feel dramatically faster.
4 Answers
A Ryzen 5 5600 is probably the best drop-in processor upgrade for that AM4 motherboard, assuming the board has a compatible BIOS. Remember that you may need to update the BIOS while the old processor is still installed. The 5600 or 5600X should pair well with a midrange card like an RX 7600 or similar.
You may not need to spend as much on the graphics card as an RX 7600 XT. A used RTX 3060 Ti, RTX 3070, RX 6600, or RX 7600 could offer good value, depending on local prices. The 16GB version is useful for some design workloads, but it is only worth paying a large premium if the applications actually benefit from the extra VRAM. A Ryzen 5 5500 or used Ryzen 5 3600 could also be a cheaper temporary CPU upgrade, though the 5600 is the stronger long-term choice.
Upgrade the graphics card first. The GTX 750 Ti is by far the weakest part of the system, so even with some CPU bottlenecking, a modern GPU should make a night-and-day difference. You can later drop in a Ryzen 5 5600, 5700X, or another compatible AM4 chip for a second major improvement, especially at 1080p.
Both parts are getting old, but the GPU is much further behind. A Ryzen 5 1600 can still run games reasonably well, while the 750 Ti will limit almost any modern graphics card. Buy the GPU now, then replace the CPU when you can afford it.

That was my thinking too, but used Ryzen 5 5600 chips cost around $170–200 where I live. At that price, upgrading both the CPU and GPU at once gets expensive pretty quickly.