Very poor performance in the editor using multiple windows

It drops below 10fps and becomes unusable, the interface lags so badly I struggle to click on things.

I’ve been working with 3 or 4 monitors ever since I started using unreal back at version 4.8. I have the main editor window and viewport in the centre screen, the content browser, details panel, viewport 2 and levels window all on my left monitor and blueprints or sequencer on the right monitor. Sometimes I even use my 50" TV as an extra screen and this is the perfect setup for me. I’m constantly working on all screens without a problem up until recently when windows 10 updated. I’m not sure if this was the cause or not, but it started happening around the same time.

If I type ‘stat gpu’ in the editor it says slate is taking up anything between 0-200ms but as soon as I close all the extra windows and just have the main window it drops to 0.6ms, so I’m guessing it has something to do with the interface rendering. It’s really inconsistent though and seems fine occasionally, then suddenly everything is at 5fps again. Then it’ll start doing it even if I only have 1 window open until I restart the editor

So far I’ve tried reinstalling the engine, updating all my drivers, even reinstalling windows and all my software. I searched the forums and answerhub and have seen a few others reporting something similar, and there’s even a report here: and here: I’ve tried running in DX12 like was suggested in one answerhub post, and pretty much everything else that I read.

Currently using 4.17.2 but I tried creating a blank project in 4.18 and it even happens there. I’ve lost 3 days work to this (game dev is my job and I’m gonna miss deadlines now) so need a solution ASAP.

I understand there is going to be some performance impact having more than one window open but it shouldn’t be this huge and never used to be a problem. Currently performance is all over the place no matter how many windows I have open

As this is a known issue with the engine and has been for some time it needs to be fixed NOW.

Setup: GTX 1080, i7 and 16gb ram, windows 10 running all latest drivers and updates.

edit: I’ve tried disconnecting all monitors apart from 1. If I open 2 separate windows on the same monitor it’s still just as bad.

the solution here worked for me not sure It is the same problem but might be useful people reading this post.