I have two EPYC servers, and 16x U.2 NVMe drives that I need to connect (8 to each server). However, the server does not have the required slots for U.2 drives. I had an idea to use one of the 5.25" bay adapters from Icy Dock (https://global.icydock.com/products-c5-s47-i0-p1.html), and put them in a chassis like the Silverstone RM41-506. But I need to find the right combination of 5.25" bays, cables and PCIe cards to make all this work.
The server has 3 free PCIe x16 slots.
For this scenario, the server cannot be changed/upgraded/etc.
For 16× U.2 NVMe (8 per EPYC server) without modifying the servers, you basically need:
PCIe → U.2 host cards, Icy Dock U.2 modules, and the right PCIe (SFF-8643/8654) cables.
PCIe Cards (Per Server)
You have 3× PCIe x16 slots, so the simplest setup is:
Use 2× PCIe x16 cards, each supporting 4× U.2 drives
Examples: HighPoint SSD7540/SSD7140, Supermicro AOC-SHG4, ASRock Rack U.2 cards.
This gives you the required 8 drives per server.
Icy Dock Modules
Use any 4-bay U.2 5.25" modules, like:
MB699VP-B (4× U.2 in one 5.25")
Install four of these in a chassis like the Silverstone RM41-506 to hold all 16 drives.
Cables
Match card to backplane:
If the card uses SFF-8654, use SFF-8654 → SFF-8643 cables
If the card uses SFF-8643, use direct SFF-8643 cables
Use Gen4-rated cables if your EPYC platform supports PCIe 4.0.
Notes
This won’t be a real external JBOF—your card will just connect via PCIe cables to the U.2 backplanes.
It still works perfectly as local NVMe storage.
Well, I don’t know what kind of u.2/u.3 drives you plan on installing in your server but chances are that these don’t need to be changed quite as often as HDDs (nvme being way more reliable).
As a result I would look for a case to mount the u.2/u.3 drives permanently and use the ~$1,700 you’d need to spend on the Icy Dock cages on more drives, or a mobo upgrade, or …