High Latency in UnrealEngine (editor and game)

Unreal Engine
1

Hi all!

I’m experiencing latency issues, sadly.
Now, the latency isn’t that bad, but it’s definitely noticable.

I did a few tests to see if I can reduce the amount of latency:
What I did to test the latency is setting up a microphone in the room, speakers blasting and measuring the duration of a mouse-click and the sound that’s supposed to play.

In FMOD Studio (clicking the play button):
WASAPI is roughly 193ms latency (through a Focusrite Scarlett interface)
ASIO is roughly 130ms latency.

In the engine I set up a simple widget with a button, and onPressed->PlayEvent2D+SetParameter
In Unreal Engine (Editor):

Output type = Autoselect (wasapi)
DSPBuffer Length = 128
DSPBufferCount = 3
FileBufferSize = 1024
Latency is around 130ms

Output type = ASIO
Untestable, no devices found in the editor

In Packaged Build (Shipping)

Output type = Autoselect (wasapi)(through a Focusrite Scarlett interface)
DSPBuffer Length = 128
DSPBufferCount = 3
FileBufferSize = 1024
Latency is around 116ms

Output type = ASIO
DSPBuffer Length = 512
DSPBufferCount = 1
FileBufferSize = 1024
Latency is around 132ms

On every output type and dsp setting there seems to be quite a bit of latency.
Is there a way to lower this?

Also, ASIO might not be a viable option (mainly because in editor it doesn’t work, and I don’t want everyone to download a driver for playing the game hah)

Thanks in advance,

Marcel

EDIT:
After lowering my DSP buffersize on the sound card (1024->128, 89ms->15ms) the latency is still 96ms

2

Hi,

Thank you for the detailed information. What version of Unreal and FMOD are you using?

3

Hi,

I’m using 4.27 (oculus source build) + FMOD 2.02.07
Although I’ve heard that WASAPI has terrible latency on it’s own, what can I expect to be the least amount of latency with that driver? I know ASIO should be able to get much, much lower latency. I couldn’t set the dsp buffer too low when using ASIO.

Also, I don’t know if this is the way to go, but I change the output driver as follow:

I modified the fmod plugin code to check the user-settings (asio enabled, dsp size/count) in the module startup (the part where the settings are read). It works, but may not be ideal since it requires a full restart for the game to use the new settings.

Any advice is welcome, thanks in advance!

4

Hi, apologies for the delayed response.

Thanks for that info.

Running simple tests without any of your improvements is showing 400ms for both FMOD and UE Sounds. I think you have pushed the improvements are far as possible currently.

On each button press are you creating a new event instance? Enabling the Load All Sample Data option in the Unreal Integration | Settings may help reduce it further for Streaming audio sources.

Could I see the modifications you made to the code?