

It’s not really about 24/7, but it is about quality of components. Enterprise gear is made using slightly better parts and tighter tolerances. Things like more expensive capacitors rated for more hours/cycles, better power filters, things like that.
The end result (and this is easily verified) is the failure rate is much, much lower than comparable consumer-grade equipment.
There is sometimes a blurry line between what counts as enterprise vs pro-sumer vs consumer gear, though.








This is highly dependent on what your needs are and how you plan to solve it. SATA-3 maxes at 6gbit, which SAS-2 had in 2009. Most cards are x8, and have at least 4 full speed SAS lanes (of whatever generation). That means 24 Gbit. PCIe x8 2.0 (from 2007) had 4 GB (32 Gbit). So if that meets your needs, you can run it on an ancient board.
However, if you need something more advanced, such as SAS-3, a SAS expander, or a card with more native lanes, then you would need to plan accordingly.
I’ve been running on an LSI 9211-4i4e, which is only a PCIe 2.0 card, for many years. I did notice my speeds dropped when I expanded the 4e to a 15-bay DAS (plus the 4 internal SATA drives), but it’s still enough to meet my needs.