8 strings from a single Raspberry PI.

[gsrunion]

Was there a discovery of a mechanism that allowed more efficient use of the RPI hardware to push more pixels or do these many string PI hat utilize extra circuitry to up the capability

Yes, they were able to leverage a video buffer for the outputs instead of using the PWM timer.

What kind of pixel numbers can they push with say, a Kulp K8-PI? I presume it wouldn't be the full 8x800 that a more powerful PI could push.

I think you can still get 8 x 800

I take it that means that even a PI4 can't both do HDMI output to a projector and drive a bunch of string local or otherwise. I would love to ditch my handful of old PI zeros for a bunch of differential receivers....next year that is.

[Poporacer]

I take it that means that even a PI4 can't both do HDMI output to a projector and drive a bunch of string local or otherwise

Yes it can, there are 2 video buffers.

[gsrunion]

Awesome