Hi. When I move the mouse on the editor, FPS drops. Is anybody having the same issue, or had it? If you know solutions, or if you have recommendations please feel free to write it.
Here is the Video: Unrael Engine 5.1 - Moving Mouse Cursor Cause FPS Drops - YouTube
Thanks.
My system is,
AMD Ryzen 9 7950x
RTX 4080
64GB Ram 6600
M2 SSD
Your hardware seems good (really good) for Unreal Engine 5, so I don’t think you should be worrying about the hardware. Try the Use Less CPU when in Background from the Editor Preferences menu. It could be lag caused by the window becoming unfocused.
I suggest some generic troubleshooting:
Hey there @Chancellorr1! Welcome to the community! When I see hitching like this, it’s often caused by high DPI mice, or certain monitors and how they are setup. Try heading into editor settings and try these two settings:
Let me know how it goes!
Have you found a solution to this? I believe to be having a similar issue.
Hey there @nrvdm.cryonaut! Unfortunately this user had never responded, however when the blank editor is lagging like that it’s often linked with a graphical issue (like Elias mentioned) or a DPI issue, likely different from your issue. I’ll slide over to your thread and answer your specifics there!
Hi, I’m having a very similar problem with the Unreal editor being weirdly laggy for example whenever I hover over tabs like file edit tools etc. From other threads and posts about similar issues I found out that when I have my editor on windowed mode the problem simingly disappears. I have also seen a pattern with most people having this problem have amd graphics cards. The thing is the editor was working fine before for me with fullscreen aswell, but I upgraded my CPU (along with new ram and mobo and m2 ssd) and I also fresh installed windows and everything. After that both 5.3 from the epic store and 4.25 from source are laggy af in fullscreen with 5.3 even crashing. Things I’ve tried so far is: Updating my drivers, playing with multiple graphics card settings and especially vsync and also trying settings in the editor such as the ones suggested above…
My specs are:
Ryzen 5 5600
Radeon 6700XT
32 GB Ram
Any ideas? For now I just opt out of full screen and resize the editor to cover the whole screen but still sometimes there is a weird flashing here and there
Hey there @dimokol! Had some new reports of issues with AMD drivers so this is definitely in the realm of possibility. Does this still occur if you are on DirectX 11?
Ok so noob question how do I run the editor on DirectX 11? Quick google search didn’t help 
No worries, you can change the RHI inside or outside of the engine, here’s a guide:
Oh ok I actually found that but I thought it only had to do with the way the game would be rendered and it wouldn’t affect the editor… Anyway thanks for the replies! I tried it and it’s the same with DirectX 11 aswell
If anyone else runs into a slow and laggy UE5 editor even though you have a strong machine like I did (i7, 4070, 32GBs of RAM, etc), make sure you have the MSI Afterburner RivaTuner / server closed. I forgot I had that running to track some temps and frame rates. It doesn’t play nice with UE5 it turns out. As soon as I closed it the lag went away. You may have a similar app running that is causing the lag as it may be trying to draw an overlay on top of UE5. So try closing other apps!
I came across this solution from here - Incredible UI lag in UE5.3.2 - #13 by Desoxi - Ask - GameDev.tv
Thought I’d repost it for others too.
