I see that the FPGA used in the MKR Vidor 4000 is an Intel Cyclone 10CL016.
According to the manufacturer specs here, this chip can be run at a number of clock speeds from 362-500 MHz.
I cannot find any information on how this is configured in the Arduino board. What clock speed is this running at?
I don't have any experience with the Vidor but I read this:
We also asked Arduino about the clock architecture of the board and they told us:
[The CPU] has its own clock which is used to generate a 48 MHz reference clock that is fed to the FPGA (and that can be removed at any time to “freeze” fpga). In addition to this reference clock, [the] FPGA has an internal RC oscillator which can’t be used as [a] precise timing reference for tolerance issues but can be used in case you don’t want [the CPU] to produce the reference clock.
Of course, the FPGA has a number of PLLs onboard that can take any valid clock and produce other frequencies. For example, in the vision application, Arduino demonstrated, the 48 MHz clock is converted into 24 MHz, 60 MHz, 100 MHz, and 120 MHz clocks by PLLs.