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.
To solove this problem, i simply turned off my MSI Afterburner, and fps incresed from ~40 to 120+
I had the same issue but I fixed it by just minimizing the window and making it full screen manually by dragging edges and my pc isn’t as powerful as the original person asking.
Hello Chancellorr,
I have the same issue but I fixed it by making the window not in full screen and I just resized the screen manually to full screen without pressing f11 or the minimize/maximize button, which helped and my pc is less powerful than yours so it should work.
For me it was Whispermode. MSI Center Pro tells me “Your performance is being monitored by whispermode”. An option hidden in GeForce Experience (which I had to download first? no idea how it turned on). Turning it off instantly made dragging around in blueprints responsive again.
My issue is because I have a pretty large Data Table (maybe 3MB) and everytime I open it, it causes the lag. For some reason, it makes the System (ntoskrnl.exe) process have high CPU. I guess from parsing all the text in memory?? The problem is, even when I close the Data Table, the issue remains. The only way to fix is is to close the Unreal (making sure that I close the Data Table first so it doesn’t reopen) and reopen. This is happening in 5.4.3 - not in 5.0.3, where I just upgraded from.
I fixed my issue - It is definitely due to the size of Data Table in the Editor. The workaround for me was to reduce the size of the specific Data Table tab, which shows all the rows. If this tab only shows about 5 - 10 rows, the editor doesn’t lag. I am keeping mine at 5 rows visible. I guess it depends how much data is in each row.
So now when I open this specific Data Table in the Unreal Engine Editor, A “Data Table” tab is at the top with the “Data Table Details” tab next to it on the right. Under both of these tabs is the “Row Editor” tab. And again, the part that works is reducing the height of the Data Table tab (or increasing the size of the Row Editor tab) to show only 5 - 10 rows.
You literally saved my life. It was actually RivaTuner what was causing large fps drop whenever opened UE project in two separate windows. Thank You kind sir!
That worked for me! if I maximize the window I get lag when I hover the content browser, but if I just manually stretch it to the corners it’s fine. It’s also fine when the mouse is in the viewport, both ways. This is when I’m using my laptop on the laptop’s screen, on an external screen I never noticed this.
