Are there differnces in life expectation for 1~2TB external (portable) HDD and external (desktop) HDD

According to current technology and most popular products, are life expectations for 1~2TB external (portable) HDD and for external (desktop) HDD significantly different? Which one will likely be more durable and last longer?

Same question if I use them as if they were both portable?

For example, Seagate FreeAgent GoFlex - Hard drive - external (portable) 1TB USB 3.0 and Seagate Expansion External Drive - Hard drive - external ( desktop) 2TB USB 3.0 ?

Thanks!

Microsoft recently released the results of a long-term, million-machine hardware failure analysis and found that, overall, laptops are more stable than desktops, including the disk subsystem. The original report is available at https://research.microsoft.com/apps/pubs/default.aspx?id=144888 with a tl;dr summary at http://www.extremetech.com/gaming/131739-microsoft-analyzes-over-a-million-pc-failures-results-shatter-enthusiast-myths.

Quoting the latter, in turn paraphrasing the former: "Desktops don’t come off looking very good here despite their sedentary nature. The team theorizes that the higher tolerances engineered into the CPU and DRAM, combined with better shock-absorbing capabilities in mobile hard drives may be responsible for the lower failure rate."

So you actually may find higher long-term reliability in a laptop-sized (2.5") drive, as they're built expecting a certain amount of abuse.

I'll let the other answer above speak to the difference between using the same desktop (3.5") hard disk internal to a PC vs. in an external enclosure.

There are a few factors here. The main point of course is, how you treat the disks. For the mobile ones it is more likely that they get stressed (like dropping while operation or getting frozen or grilled in the car).

Unless you have specially small portable devices they typically contain the same disks. The external enclosures not always have fans which can lead to heat problems. On the other hand desktops have more parts generating even more heat (like power supply, CPU and GPU).

So it really depends on your devices if they life longer or shorter. It also depends on how often you (un)plug them (compared to switching desktop off or on).

The main rule here is: the device will fail in the moment you least expect it.