Best external drive to go with iMac?

[SteelBlueTJ]

I am in need of a new external drive for my 2013 iMac. My iMac has a 250GB internal SSD just for OS X and Apps. I also use a small 240GB SSD in a 2.5" enclosure connected via USB 3.0 for everything else and it's filling up fast as 240Gb really isn't much. I have about 200GB of that filled up. I want to get something that is fast and quiet since it will be on most of the time. 1TB SSD's are still too pricey - around $400. I could buy four 2TB HDDs for that amount. Is it better to get a portable drive like a 2TB WD Passport or should I go with a desktop external like My Book? I am leaning towards the smaller portable drive mainly because its smaller and doesn't require a power adapter. Any benefit from one over the other? Thanks

 

[ColdCase]

Consumer SSDs are all 2.5 inch form factor portables.

The rotational 2.5 inch form factor portables are designed for laptop and carrying around. They will typically be more rugged (if you should drop one) and have slower performance and lower capacity.

The rotational 3.5 form factor will offer much more capacity but will not be as durable if abused. Performance will range a bit, but unless you raid two in a thunderbolt enclosure, you are not going to notice it on a USB connection.

Some USB enclosures and drives are notorious for sleep and lost connection problems. My HGTS and MacAlleys are a PITA while my Seagate and WD are solid.... but your mileage will vary. Smaller portable USB drives don't seem to be as problematic, especially SSDs but USB doesn't provide enough SATA command support (i.e TRIM and SMART) to keep SSDs running efficiently long term.

The best is subjective, a 4 bay thunderbolt enclosure would probably be the best.