I would not worry saturating one pcie.
In theory if 1 and 2 slots both use separate “channel” for data one could even use second
expander.
It is like with hard drives on ata ports used to be. Put one drive on a channel
and you get faster results. Here expander is like a drive. You put second one on second
channel and there you go.
Number of cards should not matter so much as duty cycle is so incredibly fast
that every card could do their job and move data and have some spare time left.
We just do not realize how fast that happens. 4k frame is not also very big compared to
data rate bus has. I may be wrong here but i remember something 50 megs per frame on rgb 4k.
—
Margus
https://iconstudios.eu