To me it looks like the fins are surrounding the channels making these sort of fin-tubes instead of just a flat wall of fins.
All I see in those pics on FCPU are a bunch of tubes that have been processed in a way (knurled with smooth rollers, or perhaps stamped in a press?) to give them more surface area with no conventional type fins between them.
Circles SucQ!
If your annoyed by sigs telling you to put things in your sig, then put this in your sig
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