[synthetix]

What about using a 2.5" SCSI disk? Wouldn't that give the necessary clearance?

[weblacky]

I've never seen a SCSI 2.5" HDD. There are Serial SCSI 2.5" HDDs but that's a totally different interface. SCSI drives were offered in full height (cinder block), half-height (paving stone), and low-profile 1" (what you see today in 3.5" desktop drives). I've not seen one smaller. There might have been a boutique drive that small, but if it does exists, it's as rare as hen's teeth.

[Tech_and_Music]

What about using a 2.5" SCSI disk? Wouldn't that give the necessary clearance?

You would have to find one, and that's easier said than done. 2.5" SCSI drives weren't widely used, mostly on Apple PowerBooks. Most have failed, those that haven't mostly remain in the hands of PowerBook collectors. For that reason, there's a specific 2.5" SCSI2SD PowerBook edition.

[weblacky]

I just found this on eBay, so I stand corrected. Don't know if this stuff supported Single-Ended (SE) mode...but here it is, in real life:

IBM 73GB U320 Scsi Hard Drive
https://ebay.us/LEKII9

A 2.5" U320 hard drive...Wow, so this must be where the 2.5" SAS form factor came from. Again, I won't buy this, but these were a thing I guess...

[Xav101]

I think the 2.5" SAS form factor was also driven by the need for IOPS in the enterprise segment. Some servers such as HP's IA64 servers in the early 2000s (such as the rx2800 i2) came with SFF SAS bays. Presumably so that you could throw as many disks in them as possible and get decent performance before the commercial production of the SSD was really feasible.