Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I was looking around for a cheaper SSD on Newegg and the time I'm writing this they have almost 300 2.5-inch SSD but only 12 3.5-inch ones, 9 of which are sold out. Why are there so few 3.5-inch SSD? Is it just that the demand for these drives is mostly in laptops? Why should I have to pay more for a (physically) smaller drive and then have to pay more again for a mounting piece to stick it in my computer?

share|improve this question

closed as not constructive by Breakthrough, Dave M, iglvzx, Tom Wijsman, ChrisF Mar 8 '12 at 22:37

As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance.If this question can be reworded to fit the rules in the help center, please edit the question.

There's no need for a larger form factor - the storage density is good enough for most people. Also, most manufacturers provide a 2.5-3.5" mounting adapter for free, and nearly every computer case that's manufactured now includes support for 2.5" SSDs. – Breakthrough Mar 8 '12 at 19:09
up vote 30 down vote accepted

I think it comes from a handful of factors:

  • Demand. For the last few years, laptops have been outselling desktops. Want to make a product appeal to the largest possible audience? Make it work with a laptop.
  • Compatibility. Since mounting kit adapters exist and are relatively inexpensive, making the drives 2.5" allows for the most users.
  • Many new desktop and server case designs have at least 1 native 2.5" drive mount. In some cases it's to allow for SSD usage, in others it's simply a matter of density -- you can fit quite a few more 2.5" drives in the same space as 3.5" drives. You see this more in server cases than desktop cases though.
  • Physical Space. Part of the reason that 3.5" hard drives still exist (besides inertia) is that they allow for larger platters, which allow for higher capacity drives. A large enough SSD to require a 3.5" design would be prohibitively expensive.
  • Manufacturing. It costs less to build 1 enclosure design than it does 2.

There's probably a few other things, but those all come to mind off the top of my head.

Finally, since an SSD doesn't have any moving parts, it's not prone to moving around inside a desktop system. Unless your system uses a tool-less mounting system that requires 3.5" SATA drives with the power and data connectors in the appropriate place (e.g. Mac Pro, Dell OptiPlexes, etc.), you can just use a piece of velcro, a plastic wire tie, double-sided tape, or any other solution you can think of to keep the drive from moving very far.

For the few desktop systems I deploy that have SSDs, I just leave the drive sitting at the bottom of the case if there's no other way to mount them properly. It's far cheaper than buying additional kit just to mount them "nicely". Those systems have plenty of thermal headroom such that heat simply isn't an issue.

share|improve this answer
Thanks for such a comprehensive answer. – Psycho_Penguin Mar 8 '12 at 21:00
Plus brackets are $2. – surfasb Mar 8 '12 at 21:08
Very well answered and comprehensively explained. – Prasad Feb 1 '13 at 18:34
Do you have a pic of many 2.5" drives in a 3.5" bay? – barlop Oct 9 '15 at 12:01
@barlop: That is slightly confusingly worded. What I was referring to are storage servers with multiple drive bays. e.g. In a 2U rackmount enclosure, it's possible to fit more 2.5" drives than 3.5" drives. That said, products like the Icy Dock MB082SP allow for installing two 9.5mm 2.5" drives into a single 3.5" half-height bay. That was simply the first product I found on Google, not an endorsement for that particular item. – afrazier Oct 9 '15 at 15:05

Not the answer you're looking for? Browse other questions tagged .