Would IDEALLY like to fit about 24 x 3.5" HDDs... 8 slots in case I need to recover a RAID array or clone drives. 4 more free for to make targets when I do recoveries. And MAYBE! (I know know how transparent ESXi really can let your hard drives be, which is CRUCIAL in this case alone with the PCI slots being associated with specific OS's) ... But, I have one program I use which is via a thin DOS installation, and then uses it's own SATA commands (can't have ESXi interfering. Have 2 more that needs ABSOLUTE -- 100% control over their PCI cards, (they secretly run operating systems, and Id like to be able to install the application without it saying it sees ESXi. (I've seen the thing that lets you pass things through -- but I don't know if I can map it to an actual SLOT, and I don't know if it's close to bare metal, or if it IS bare metal. And lastly, I want to make a RAID Array, probably internal drives as well as a SAS controller from an external enclosure ... for a tiered (I think I read this was possible) ZFS Array / nested array... And if NVMe drives keep coming down - maybe I'd want one that's a mixture of 2.5" NVMe and 3.5" slots for older systems which are what's failing these days. Anyone track well enough to make suggestions? Thanks!!