3647 side-air-channel cpu heat sink?

[BryceRocky]

I'm looking at getting a passive heatsink to be used with my supermicro X11-DPI-n board and cse 216. However,
I see two possible:
Supermicro SNK-P0068PS 2U Passive CPU Heat Sink For LGA3647-0 Socket
Supermicro SNK-P0068PSC 2U Proprietary Passive Side-Air-Channel CPU Heat Sink For LGA-3647-0 Socket

Does anyone know what the difference between these two are? In particular, what's a side-air-channel and which would be most appropriate for use with the cse 216 air shroud? Thanks!

-Bryce

 

[i386]

I think one is for non (e)atx/custom layout mainboards, and the other is a standard heatsink for atx boards.