[aDfbrtVt]

As others have mentioned, this is mostly a proof of concept for a high core count weakly-coupled fibre from Sumitomo. I also want to highlight the use of a 19 channels MIMO receiver structure which is completely impractical. The linked article also fails to mention a figure for MIMO gain.

[eqvinox]

Worse, it's offline MIMO processing! ;D

I would guesstimate that if you try to run it live, the receiver [or rather its DSPs] would consume >100W of power, maybe even >1000W. (These things evolve & improve though.)

(Also, a kilowatt for the receiver is entirely acceptable for a submarine cable.)

[aDfbrtVt]

To get a ballpark power usage, we can look at comparable (for some definition thereof) commercial offerings. Take a public datasheet from Arista[1], they quote 16W typical for a 400Gbps module for 120km of reach. You would need 2500 modems at 16W (38kW) jointly decoding (i.e. very close together) to process this data rate. GPU compute has really pushed the boundaries on thermal management, but this would be far more thermally dense.

[1] https://www.arista.com/assets/data/pdf/Datasheets/400ZR_DCI_...