Go Back   Cockos Incorporated Forums > REAPER Forums > REAPER General Discussion Forum

Reply
 
Thread Tools Display Modes
Old 11-29-2021, 07:24 AM   #1
inoto
Human being with feelings
 
Join Date: Nov 2021
Posts: 47
Default Measuring Latency (RTL) in Reaper, WASAPI modes...

I'm trying to measure my Realtek sound card's WASAPI round-trip latency using Reaper, with one track for playback and the other for recording (with a loopback cable on my motherboard).
There are two general issues/questions:

1. The results, at least when using WASAPI shared, are not consistent with the results in Oblique Audio's RTL Utility.
I already disabled the "Use audio driver reported latency". Is there something else that I need to disable, to make sure Reaper is not changing the latency?

2. Is there a way to select the "Windows Audio (Low Latency Mode)" mode that can be selected in the RTL Utility?
From a brief observation, it seems that it probably gets enabled if I keep the RTL Utility open with this mode selected before starting Reaper. Despite being low latency, it's a shared WASAPI mode, so both apps can use it. But again, the latency results differ between Reaper and the RTL Utility, so I'd like to know what's going on.
inoto is offline   Reply With Quote
Old 11-29-2021, 08:14 AM   #2
domzy
Human being with feelings
 
Join Date: Feb 2017
Posts: 4,823
Default

Doesn't shared mode mean that multiple apps are using the hardware? I'm not sure i would expect consistent performance if other apps can interfere?
domzy is offline   Reply With Quote
Old 11-29-2021, 08:33 AM   #3
pepe44
Human being with feelings
 
pepe44's Avatar
 
Join Date: Jul 2013
Location: Portugal
Posts: 1,827
Default

Are you running the tests on a laptop? make sure its set to high performance, battery and different settings might affect the way everything works.

Check this article:
https://www.donyaquick.com/minimizin...0-with-wasapi/
pepe44 is offline   Reply With Quote
Old 11-29-2021, 10:03 AM   #4
Stella645
Human being with feelings
 
Stella645's Avatar
 
Join Date: Sep 2008
Location: UK
Posts: 3,648
Default

Don't the recent versions of RTL utility have a warning dialogue saying to avoid testing with windows drivers and only use ASIO?

That suggests to me they know it will not necessarily be accurate.

If you can measure and repeat with near identical results in Reaper this is your real world result. What would it matter what result you get outside of the DAW.
__________________
Funkatarium 30th Anniversary Remixes
Ltd Edition Vinyl finally available on Bandcamp.
https://funkatarium.bandcamp.com/alb...ersary-remixes
Stella645 is online now   Reply With Quote
Old 11-29-2021, 12:36 PM   #5
inoto
Human being with feelings
 
Join Date: Nov 2021
Posts: 47
Default

Quote:
Originally Posted by pepe44 View Post
Are you running the tests on a laptop? make sure its set to high performance, battery and different settings might affect the way everything works.
Thanks, but no, it's not a laptop and switching to high performance doesn't help.

Anyway, the results are pretty consistent in the RTL Utility, but not as consistent in Reaper. And there's always a significant difference in RTL between these two apps even though the settings look the same — although Reaper only has one WASAPI shared mode, whereas the RTL Utility has two.

As I said, it looks like I can "enable" the Low Latency shared WASAPI mode in Reaper by using it in the RTL Utility first.
It would be nice if this mode was accessible in Reaper directly. I guess I should post it in the Feature Request section.

But I'm also just curious about how it all works.

This is a very specific topic and I don't expect most people to know or care about it. But I do.
inoto is offline   Reply With Quote
Old 11-29-2021, 01:41 PM   #6
Stella645
Human being with feelings
 
Stella645's Avatar
 
Join Date: Sep 2008
Location: UK
Posts: 3,648
Default

Quote:
Originally Posted by inoto View Post

This is a very specific topic and I don't expect most people to know or care about it. But I do.
I'd think that once most people get to the point of caring about measuring RTL they also care about using an interface with a decent ASIO driver.
__________________
Funkatarium 30th Anniversary Remixes
Ltd Edition Vinyl finally available on Bandcamp.
https://funkatarium.bandcamp.com/alb...ersary-remixes
Stella645 is online now   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -7. The time now is 08:52 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.