[Bug Report] Desktop FPS tanks when tooltips are visible

Whenever a mouseover tooltip appears in the editor (project tooltip or asset tooltip), the desktop FPS drops to circa 1-2 FPS, and does not return to normal until the tooltip is gone (most easily achieved by letting another window grab focus).

Other tooltips such as the simple text ones brought up when mousing over toolbar buttons only affect the editor and not other windows on the desktop.

The issue mostly occurs when another application is using the GPU at the same time (such as a video playing on another monitor on YouTube or in VLC), but often occurs when scrolling in the content browser as well.

Steps to reproduce for multiple applications:

  1. Open the editor (compiled from the Release branch)
  2. Open another application and start some other GPU application (agar.io, YouTube, webGL experiments)
  3. With both applications visible, mouse over a UI element that would produce a tooltip.
  4. The FPS in both applications should slow to a crawl. The tooltip may have a slight delay before rendering properly where the previously rendered frame will be visible inside the box for a few moments.

Moving the mouse at any point will have the tooltip, editor and secondary application lagging behind and moving very sluggishly, until the tooltip removed from the screen.

Steps to reproduce for just the editor:

  1. Open the editor (compiled from the Release branch)
  2. With the editor visible, mouse over an asset in the content browser that would produce a tooltip.
  3. The rendered tooltip will show up, but move very sluggishly when the cursor moves. The FPS in the viewport will slow down as well.

This has been tested with the UI element producing the tooltip (most often the Content Browser) both as a free window and as a tab inside the main editor window.

The engine is a direct-from-github compilation of the Release branch.

System information:
Linux Mint Cinnamon 17.3 Rosa (64-bit)
Nvida GeForce GTX 660Ti, 2048MB (Driver version nvidia-361.16 or nvidia-352-updates)
Engine Version: 4.11.0-0+UE4

Hey -

I’m not noticing any lag/fps drop when I mouse over an asset in the content browser or over a blueprint node. Could you include a short video of what exactly you’re seeing? Additionally, are you seeing this behavior in multiple projects or is it only occurring for a single project? If possible, can you let me know if you see the same results using Ubuntu rather than Mint?

Cheers

Sure thing, here’s a video: 2016 01 13 20 09 13 - YouTube
It’s mostly visible right at the start in the project browser, where the tooltip is lagging behind quite a bit - what you see here, though, is quite a lot better than it was yesterday. Not sure what the difference is.

Additionally, at 1:50 - 2:05, you can see the editor freeze up for a few seconds when I have multiple assets selected and try to scroll. At 2:23 -2:27, you can see the input lag causing the selection to “jump” from the lower two assets to the two above it.

This is happening in all project and the entirety of the editor, as you can see with the project browser.

Hey -

Thank you for the video, I can see what you mean about selecting multiple assets. I have entered a report (UE-25471) to investigate the drop in fps when tooltips appear.

Cheers

Hey,

i have the same Problem.
i compiled the engine from source and started it with:

./UE4Editor -opengl4
./UE4Editor -vulkan
./UE4Editor

By all commands the same Problem Tearing an very Low Fps
it is only when UE4 running.

System information:

  • Manjaro Linux (64bit)
  • Nvidia 690 GTX (Driver Version: 370.28)
  • UE4 version: 4.12.5 and 4.13.1

Logfile: [link text][1]
and pastebin link [link text][2]

Hey ,

i’m also having this issue on 4.14 and the issue mentioned to comment here to reopen it as it’s set to Wont Fix.
Whenever I mouse over an icon in the editor, my FPS drops by half.
Additionally, my game has poor performance because I’m using a widget HUD.

Hey Genova-

I was not able to reproduce this behavior in a new project locally. Can you let me know if you are seeing this in a new empty project with starter content? Additionally, can you provide a copy of the project where this is occurring?

Until the bug is fixed a workaround is to disable tooltips:

  1. Open the console (?) with ~
  2. Enter Slate.AllowToolTips 0

Unfortunately this has to be done every time the editor is started.

https://forums.unrealengine.com/unreal-engine/feedback-for-epic/34904-disable-tooltips

In v4.24.0 this command has changed to Slate.EnableTooltips 0

Hello ,

I’m having this issue on v4.24.3 / Ubuntu 20.04; I have also tested this under v4.24.1 / Ubuntu 19.04. I have posted a video of me using a blank project demonstrating the degrade in performance.

You can find this video here: UE4 4.24.3 - Tooltips Cause Low FPS - Ubuntu 20.04 (and 19.04) - YouTube

Let me know if you need anymore details or if there is a more appropriate place for me to get this bug reissued

This does not fix the issue; thanks though!

try remove this

After keeping the tooltips disabled, I’ve noticed other things cause the same FPS drops. Specifically, opening the menus from the menubar, clicking on dropdown context menus, and even context menus pressing Right Click. Generally speaking, it seems to happen whenever something is drawn over the editor.