5-1/2" hard drive with massive capacity to fit in 5-1/2" optical slot

[#1]

I am not expert on storage, however I have noticed faster write performance on the outside cylinders compared to the inside. As disk sizes have skyrocketed it seems that performance has picked up while rpm has not changed. So I deduce from this that density is the explanation.

So, why not build a disk with massive capacity to fit in the 5-1/2" optical bays most PC cases have? Performance should be amazing, even at lower rpm's, which should be good for longevity and power use. Now that motherboards and HBA's are getting past the 2.1 TB limit, and advanced format drives are here, build us a large, reliable disk to go in the 5-1/2" slot.

[#2]

I have generated a sample drive in Solid Works with 2 stacks of 12 platters that results in a 48 head drive with 3 1/2 inch platters. A 96 head drive with 4 stacks of 2.5 inch platters would also fit in a full size / full height drive enclosure. The heads are mounted on opposing arms so they all move together. An X shaped arm could position 96 heads on 4 stacks of twelve 2.5 inch platters. That would provide about 3,480MB/Sec if ran at VelociRaptor rates. The drive could also spin much slower and still provide fast results with longer lifespan. Also RAID could be built into the drive.

[#3]

The last 5.25 inch disk I saw was make by Quantum under the their Big Foot series. I called the flat foot due to the pathetic life of the product.

I expect 40K power on hours (I use lots of disk in my server) per disk. If they cannot do that, they are crap in my opinion.

My gaming box has 1 large disk, the server has a puny boot disk and 3 larger ones.

I have 3 more in bags as spares. More in spare machines.

[#4]

I agree with the OP - make a full-size 5.25" HD, and/or even make a 5.25" double-height drive - just keep the SATA and power connectors in the same relative position so they'll slide in the Mac Pro's drive bays  ;-).

Lots of space then for more and bigger platters without the never-ending race for greater areal density, and the associated problems with errors and head positioning. Perhaps (as the OP says) they could also run slower and quieter without any loss of performance, and reliability would increase?

I can actually remember the first hard drives - referred to back then as 'Winchester'  - which were 5.25" and double-height. Hitachi made one in 1989 with 8 platters at 3600rpm. I've always wondered why this form factor isn't still manufactured as an option for desktop users who need lots of space.

As for sales - I'm sure if you built it, the people would come and the manufacturers would then adapt their casings. The RAID and NAS market segment would probably love big, fast, quiet and more reliable drives.