What’s the best way to upgrade this AM4 PC for 1440p gaming on a £1,000 budget?

For this kind of gaming, I’d lean toward a Ryzen 7 5700X3D paired with a used RTX 4070. The graphics card will have the biggest effect at 1440p, so I wouldn’t overspend on the CPU if it means dropping to a much weaker GPU. Check the power requirements and condition of any used card, and make sure your PSU is suitable.

If keeping costs down is the priority, a Ryzen 5 5600 with a stronger graphics card is also a sensible route. Something in the RX 9060 XT class, preferably the 16GB version, or a faster RX 9070 if the budget stretches, would generally be a better 1440p investment than putting most of the money into a high-end AM4 CPU.

Before buying anything, compare real 1440p benchmarks for the specific games you play. The RTX 4070 is likely the value sweet spot among the listed cards; the 4070 Super only makes sense if the price difference is fairly small. Also check whether your existing cooler, case airflow, and PSU can handle the upgrade.

A cheaper X3D chip, such as a 5500X3D if it’s available at a good price, could be enough for gaming and would leave more of the budget for the GPU. You probably don’t need a new motherboard just to move to one of these processors, although you should update the B450 BIOS before swapping CPUs. PCIe 3.0 shouldn’t make a noticeable difference for this setup.