Sending a copy of the experimental display to a secondary monitor

Hi Chris -

I hope you and everyone in the DiCarlo lab are healthy and safe!

A quick question for you as we start connecting Eyelink/MWorks/ViewPixx/Blackrock.

We would like to send a copy of the experimental display (ViewPixx) from the Mac to a secondary console monitor at the rig. We will use this secondary monitor to map receptive fields and visualize trial events.

The question is: How do we best split the video output from MWorks so that it goes to the ViewPixx at full resolution and to this secondary console monitor (doesn’t need to be at full resolution)?

Will I need some kind of video splitter or graphics card to do this? And if so - can you please guide us on setting up this connection? As of right now, the console monitors we’re looking into will likely take HDMI, VGA or Display port inputs.

BTW - When I consulted with Sophie Kenny (@ViewPixx), she suggested the possibility of taking the output of the ViewPixx monitor, and running it back into the experimenter room to a console monitor. However, she mentioned that most modern monitors (eg. an the LG we had in mind) can’t keep up with the ViewPixx output without blinking/losing signal. So I’m hoping we can do this another way. She also suggested asking you since you’re more familiar with the video output of MWorks.

Eager to hear your thoughts on how to best (most easily) accomplish this task.


Hi Yasmine,

Physically splitting the output signal is probably the best approach, as it doesn’t add any load to your Mac’s graphics card. However, for that to work, the secondary display would need to have specs that are compatible with those of your VIEWPixx/3D (1920x1080 resolution, 120Hz refresh rate, 10-bit per RGB channel color). It may be hard to find a monitor with those specs, which I think was Sophie’s point. Also, the issue is the same whether you use an external splitter between the Mac and the VIEWPixx or use the VIEWPixx’s builtin output, so I’d personally opt for the latter.

Alternatively, you could use macOS’ video mirroring to drive the secondary display. This would free you to use the display of your choice, at the cost of added work for the graphics card. However, given that the Mac Pro has a very capable GPU, that may not be an issue. (Also, I’m not sure if macOS supports mirroring to just one display. If it forces you to mirror to all attached displays, then you wouldn’t be able to use one display for controlling MWClient.)


Hi Chris -

Thanks for this info! We’re looking into these two options currently
(monitor with the right specs and mirroring on the mac).

FYI - it turns out that the console monitor not only needs to be the right
resolution and refresh rate, but it also needs to have a dual-link DVI port
(which really limits the options quite a bit).

Many thanks,