So when I play my UE5 game on my 1080p75hz monitor, I get perfect framerates, but when I play that same unreal project on my 4K monitor at 50% screen resolution (1080p), I get very noticeable lag and stutter. It even can go as low as 40 fps.
My project so far only has 650 or so actors in it, so it shouldn’t really be an issue. Also, if I set my 4K monitor’s resolution to 1080p, the framerates are at a perfect 60, with no lag or stutter.
Does anyone know why this is happening, and how I can fix this?
Thanks!
well… your operating system aka windows has to upscale your 1080p render to 4k. this is an additional pass your system has to render. i dunno how microsoft does that. depending on what gpu or igpu your system uses, it may transfer the frame down to ram, upscale it on the igpu and send it back to the gpu for display. that would explain the lag. not sure what todo about this, tho. you could disable the igpu, so windows should not try to transfer the image downwards and back up.
(jsyk. old shool laptop optimus does the same. the rendered frame is downed and the host gpu manages it to display. the down is a render slave tax. got better mux switch compatibiliy tho. ms is not great with dual device switch code. hmm)