And yes it they all run FPGA's.. But they use multiple FPGA's.. So one could handle multiviewer and input frame buffering.. While the other does the actual mixing of 2 or 3 data streams and apply effect before going out again.. Nobody knows only BMD.. But for sure there are 2 to 4/5 FPGA's in every atem..
And yes FPGA's are way more flexable.. But knowing that these FPGA's run quite hot.. And due too costs they will use the FPGA that can just handle it.. Why would you pay $20 more for an FPGA (that runs 50% of its capacity) if a step lower can handle it too.. (While running on 80/90% capacity..)..
I hear you think. What is $20 to a unit of $1000.. Wait until you have to build 100.000 pieces of them..
So a lot of gear is running on there tows.. Not much room to implement wild features that take a lot of resources..
This is the difference between Blackmagic and say Sony.. Or like Toyota and Bentley.. It will still drive. Get you from A to B. Will have some features.. But it is not that luxurious..
And Fair to say.. BMD makes a good product.. Implemented much nice features down the years. (Shading from software (Saves you a lot of RCP panels $3000/4000 a piece!!), PTZ control, Talkback and Tally in the SDI lines.. ) and you have acces to all those features for ONLY $999
If BMD was not been there you would have paid $40.000+ for a Sony panel..
No! Correction: you would not been even in this business!
So lets thanks BMD for the revolution they have started 7 years ago with the Atem mixer!! Because they have done a heck of a job bringing the prices of broadcasting down and make it affordable for the smaller companies to go in business with HD live productions
And yes there are things that could have a better implementation.. But after 7 years they still did not fix the Audio deley to match the video output.. So if your production is just that important.. Then fix it with external hardware and create your own work arrounds for those things that bugs you..
(i do run digital mixers like the Behringer X32 to fix the audio delay )