All output freezes randomly

[365Prod]

I have seen a post here and there but I am having an issue where my all my outputs, even with no external monitors attached, are freezing. I will read between 30 and 60 fps for 99% of the time but then every 60 to 120 second all content dresses for a half second while the fps says it drops to 15fps.
All content is DXV3, either 30 or 60 fps. Tried content I converted in MPEG stream clip and content I have exported straight from Adobe.

Running Arena 5.0.4
Not running SMPTE
All Systems running OSX 10.11.5

Hardware:
System 1
MacPro (2013 Trashcan)
6 Core
Dual D500
32GB RAM

System 2
MacPro (2013 Trashcan)
6 Core
Dual D700
64GB RAM

System 3
Retina MacBook Pro 2013
Core i7
NVIDIA GeForce GT 750M
15GB RAM

I even wiped both MacPro and started with just Arena and still had the issue. Had both MacPro in to Apple trying to see if it was hardware but they came up clean.

[Zoltán]

when updating to yosemite from mavericks I had a something very similar issue, then on el capitan no issue again.
for me it affected even google chrome scrolling.

[Joris]

A drop in fps does indicate that Arena is actually struggling with something. It could be something internal rendering related, or that it cannot get the data from the disk fast enough.

Could you check the system activity via Activity Monitor., particularly CPU load and disk access? I'm curious to hear if there are any spikes every 60 to 120 seconds.