Sierra and BlackMagic Decklink

[katza]

Hello wizards!
I have a very stable Hackintosh (Asus P8 H77-M PRO) with a Win10 & Sierra Dual-Boot.
I installed a BlackMagic Design Decklink Card for professional Use.
I have checked the SDI Input latency on both Win10 & Sierra.
Windows gets about 3 frames delay while sierra gets about 5 frames (and those 2 extra frames are a big deal...)
Both has the latest drivers.
Anyone have any Idea about where should I look to resolve this problem?
Thanks!

 

[Midphase]

How are you determining the exact lag?

 

[katza]

How are you determining the exact lag?

I'm rolling an onscreen timecode on a seperate computer screen then pointing an SDI video camera at that screen and feeding the deckling on the second computer screen.
As they roll side by side I'm taking a picture with a stills cam and see the difference in the timecode.

 

[katza]

NO clue people?