I tried to play game on 1440p on my 40" Philips and it looked good, I did it only to see how it looks, cause 980Ti is fine for 4K and I play only in 4K. Some games I played before on 27" 1440p started automatically at 1440p and I didn't even noticed it till checked the settings in menu. in-game you can see the difference obviously, but it is still playable and looks good. However I've read different opinions, it depends on a screen/size. Some screens are fine down-scaling like that, some not. With 40" you can always force it to 34" and save on gpu power, having perfect quality.