As long as you realize that you are still seeing the lower res. Pixels are physical lights. You can't magically add pixels to see a higher res. You'd have to get a new monitor. Downsampling is just an anti aliasing technique. As with computing any higher res will make your gpu work harder so will use more power. You can use dsr, go into nvidia control panel and you can turn it on and set the dsr factor there. You don't need to output at 4k, it goes from 1.2 up to 4x res. So if you are getting decent fps now, a lower setting won't have a big effect.