Slow playback?

Hi all,

I'm having a issues with slow playback (Choppy) in both editing tab and coloring tab. I had this in 11, reading forums and talking with BM said it was a issue with the Fusion Drive. I just wanted to confirm that its still a issue with someone trying to run Resolve 12 on the same computer or maybe its something I'm doing wrong?
I have the default setting running and just installed resolve. Updated everything on my end.
Here are my computer specs:
iMac (Retina 5K, 27-inch, Late 2014)
4.0GHz quad-core Intel Core i7
16GB ram
1TB Fusion Drive
AMD Radeon R9 M295X with 4GB
(Note) FCPX, Adobe CC PP and After Effect all run with no problems
Please help Thank you

[Dwaine Maggart]

What OSX version?

OS X Yosemite 10.10.4


No crashing or anything like that, Just really bad video when i hit play. I tried different formats, frame rates, 1080 and 4k all the same result. Its more choppy then slow if you know what i mean. Theres nothing running in the background either. My other NLE (FCPX, Adobe CC) no lag, no anything, even with effects video runs fine?

[Dwaine Maggart]

This is surprising as others have commented on how much better things like H.264 playback are in V12.

Have you ever had a BMD UltraStudio I/O device connected to the iMac?

Is this happening on HD timelines?