Hi,
The reason why you’re getting more when not using the Blackmagic presets because of how the video data is handled.
In Adobe’s presets using the Mercury Playback Engine, the path is relatively straightforward. Everything gets pushed to the graphics card and then directly out via the DVI port.
When you want to use a proper video output, the data then has to make its way back to the driver before being sent out via HD-SDI, HDMI or analog video. However, this ensures that your output is always proper high quality video output in the correct colorspace and resolution.
That said, we’re earnestly looking at how we can improve this.
regards
Kristian Lam
Blackmagic Design