Then get a modern GPU and limit the power to what your 1080 draws. It will still be significantly faster. GPU power is out of control these days, if you knock 10% off the power budget you generally only lose a few percentage of performance.
Cutting the 5090 down from 575w to 400w is a 10% perf decrease.
Cutting the 5090 down from 575w to 400w is a 10% perf decrease.