Search in
Sort by:

Question Status:

Search help

  • Simple searches use one or more words. Separate the words with spaces (cat dog) to search cat,dog or both. Separate the words with plus signs (cat +dog) to search for items that may contain cat but must contain dog.
  • You can further refine your search on the search results page, where you can search by keywords, author, topic. These can be combined with each other. Examples
    • cat dog --matches anything with cat,dog or both
    • cat +dog --searches for cat +dog where dog is a mandatory term
    • cat -dog -- searches for cat excluding any result containing dog
    • [cats] —will restrict your search to results with topic named "cats"
    • [cats] [dogs] —will restrict your search to results with both topics, "cats", and "dogs"

Office Holiday

Epic Games' offices will be on holiday from June 22nd to July 7th. During this period support will be limited. Our offices will reopen on Monday, July 8th. 

Regular frame drops [Vive] [many games]

Hello. I noticed today when profiling my Vive game that I was getting a single frame drop about once a second. Popping open the SteamVR Developer's Frame Timing charts I was able to see a pattern of regularly dropped frames. After doing some googling I came across this reddit post.

So I decided to check out some other UE4 games in my library to look for the pattern:

Trials: imgur link

Brookhaven Experiment Demo: imgur link

and my game: imgur link //spike at the end removing focus from the editor window

Is this a known issue?

Product Version: UE 4.13
more ▼

asked Oct 11 '16 at 05:28 AM in Rendering

avatar image

103 13 15 19

(comments are locked)
10|2000 characters needed characters left
Viewable by all users

1 answer: sort voted first

Hello Dr_Jerm,

The issue described above sounds like the result of Vsync. VSync stands for Vertical Synchronization. The basic idea is that synchronizes your FPS with your monitor's refresh rate. The purpose is to eliminate something called "tearing". This can cause frames to drop if the refresh rate of your monitor is not in sync with your fps. I hope that this information helps.

Make it a great day

more ▼

answered Oct 11 '16 at 08:32 PM

avatar image

Rudy Q ♦♦ STAFF
47.4k 545 132 524

avatar image Dr_Jerm Oct 15 '16 at 11:19 PM

So the Vive has a 90 Hz refresh rate and our project and others are easily running at 90fps. Should we be disabling VSync? I'm not sure what "the solution" is here...

avatar image Rudy Q ♦♦ STAFF Oct 17 '16 at 05:40 PM

I was providing information on what I thought the issue might be. However, I do have a request. Could you provide your Dxdiag so as to eliminate a few possibilities?

avatar image Dr_Jerm Oct 17 '16 at 06:45 PM

See attached. Thanks for your helplink text

dxdiag.txt (70.2 kB)
avatar image Rudy Q ♦♦ STAFF Oct 20 '16 at 08:06 PM

After further testing, I have been unable to reproduce this issue on our end. Could you provide an example project that is showing the issue that you mentioned above?

avatar image Dr_Jerm Oct 20 '16 at 08:27 PM

The easiest is running the projects I linked (Trials on Tatooine, Brookhaven Experiment, Raw Data [from the reddit post]). However if you wanted to look at my project, what is the suggested way to provide that?

avatar image Rudy Q ♦♦ STAFF Oct 20 '16 at 08:36 PM

You could provide a zipped down version via drop box or google drive. If you would like to provide it privately, you could do so be sending it in a private message to me on the forums.

avatar image Dr_Jerm Oct 20 '16 at 10:03 PM

Forum message sent.

avatar image Dr_Jerm Oct 30 '16 at 10:11 PM

Bump bump.

avatar image DeathUman Nov 07 '16 at 02:01 PM

Bump. I'm experiencing this issues across a lot of Unreal engine made game like RedOut. I think that something has to do with postprocess like temporal antialiasing or some screenspace effect that hasn't been disabled as it should and as a VR developer myself I'm very interested in what is causing this.

(comments are locked)
10|2000 characters needed characters left
Viewable by all users
Your answer
toggle preview:

Up to 5 attachments (including images) can be used with a maximum of 5.2 MB each and 5.2 MB total.

Follow this question

Once you sign in you will be able to subscribe for any updates here

Answers to this question