iMac 5K Late 2015 and Sierra=> choppy, unresponsive GUI

[rustonium]

Hi, first post here. I would like to chime in on this issue.

After 10+ years of using Pro Tools as my primary DAW, I'm thinking about switching to REAPER. So I'm in the process of putting REAPER through its paces.

The single thing holding me back from switching right now is exactly the issue described in this thread by Robert Johnson. My machine is an upgraded MacPro5,1 from Create.Pro with the following config:

- CPU: Intel Xeon X5690 6-core 3.46 GHz
- GPU: AMD Radeon RX 480
- RAM: 32 GB
- SSD drive
- macOS Sierra
- 4K Display

I would suggest this would be more than enough to run REAPER smoothly. But this is not the case, please take a look at this video:
https://www.youtube.com/watch?v=Ra1CXhXDhWE
(REAPER macOS Sierra 4K - lag)

Now compare to REAPER in Windows 10 - on the same machine - which runs absolutely smooth:
https://www.youtube.com/watch?v=nNGnGJZf9mU
(REAPER Windows 10 4K - No GUI lag)

Let me clarify: It is not the un-smoothness I have a problem with. It's the fact that the time selection doesn't follow the movements of the mouse - instead it lags behind. I'm used to editing very fast, and the lag makes editing unpleasant.

Now, where the problem gets real to me is when the lag makes time selecting imprecise. When doing a fast time selection, the time selection sometimes doesn't reach to where the mouse has stopped:
https://www.youtube.com/watch?v=OsVlHm05nns
(REAPER macOS Sierra 4K - lag makes time selection imprecise)

Please note, that this isn't just theoretical. I have experienced the implication of this issue when doing real editing work in REAPER.


In Pro Tools 12, on the same machine and macOS, time selecting has no lag. Track resizing does however lag - but that doesn't affect editing:
https://www.youtube.com/watch?v=MOSmsd85pTc
(Pro Tools macOS Sierra 4K - only lag in track resizing)


Some things I have tried to resolve the issue:
- Also tried with a clean Yosemite install - issue is the same.
- Actually I also purchased an Nvidia GTX 950 GPU (because I read somewhere that Nvidia GPU's might be better for GUI responsiveness than AMD). Issue still the same, no change.


I'm only writing this in the hope that it might help the team to sort out the issue - 'cause otherwise I'm really diggin' REAPER!

All the best