What homelab people who do not work with/in a data center daily doesn't realize is how noisy and power hungry is the equipment they procure.
They got a managed switch, nice. It has VLANs, stacking, etc. nice. How many 48 port switches you can possibly stack in a home? You got a Sun ZFS7420. Great. That's a rack with two controllers with 1TB RAM each. That thing screams. An entry level 7320 is maybe workable, but you can't do 7420 at home. Same for HPE/Dell/Netapp storage boxen.
Doing Infiniband is home is another thing I can't understand. Fiber cables are extremely expensive. Copper is range limited and thick, plus unless you do HPC, its latency and speed doesn't mean much. Go fiber Ethernet. Much more practical.
I understand the curiosity and willingness to play, but it's not that practical to play with these at home (noise, space, heat, power wise). I also buy high end consumer hardware. TP-Link has 4/8 port smart managed SOHO switches for example, they even have PoE. Power your Raspi cluster via PoE with less cables and get some respectable computing power with no noise. Neat! No?
Dell's Rack servers are generally not noisy at idle, but a 2U server under some real load is unbearable. What's funny that an Intel N95 has the same power with an i7-3770K with better SIMD support while being 4x more efficient, and that thing is not slow by any means.