How clear cut is it when I'm storing a bunch of compressed video files? It's totally a waste at that point to even attempt to compress these files.
That said, a surprising number of video sources use sparse file type setups, and I've gotten pretty good compression (up to 60%) using LZ4 with NVR files from some brands.
But we are talking about multi-tenant systems here. You will get better performance and/or better prices if the system finds compressible data for other customers.
All the benefits hold, even for you with non compressible data, if there is an overall benefit.
Hitting a bottleneck less often then this will reduce your tail latencies, too.
It is just that _your files_ won't contribute to these improvements. But you get all the benefits as well.
It would be waste to _not_ use the CPU time.
Granted, the CPU powet consumption would drop with enabled power management, but that's only marginal gains as the CPU is likely busy anyway and the total duration of busy time might drop (race to sleep)
I have used this inverted logic to great extends. E.g. when expanding data center capacity I was usually swapping old harware for new hardware once it arrived. It is way better to have the older generations as spares and use the new capacity at the most utilized places.
Do not waste the things you pay for!