Apple iMac 21-inch review (late-2015): A little computer with a LOT of pixels

So, the 27-inch iMac is too big, you don’t want a MacBook and the Mac mini doesn’t quite hit the spot. The 21.5-inch iMac could be just what you’ve been looking for. Following in the much larger footsteps of its king-sized cousin, the baby iMac of the family has upped its game with updated processors and an optional Retina 4K display.

Apple 21.5-inch iMac (2015) review: What’s new?

I know it’s bad form to start a review on a downer but, well, here we are. In an act of unspeakable cruelty, Apple initially neglected to send us the model with the Retina 4K display (Apple has since rectified this cruel omission, so I’ve added my thoughts on the 4K display on the next page). My hopes, dashed. Instead, I excitedly ripped open the packaging to reveal the entry-level £899 model ($995 on Amazon US) – the cheapest iMac of the lot. Disappointed isn’t the word.

There’s no 4K display, no Fusion Drive – not even a Magic Trackpad 2 to soften the blow (that’s £44 extra, thanks). Instead, all you get is an iMac with a 21.5in Full HD display, a 1.6GHz Core i5 processor, 8GB of non-upgradeable RAM and a bog-standard 1TB hard disk. Oh, and a Magic Keyboard and a Magic Mouse. For £899 (though the next model up is now pretty near in price at £964 on Amazon UK). If that doesn’t sound like anything remarkable, it’s because it isn’t – this is intended as a basic, everyday computer. Albeit a rather expensive one.

Want something a bit quicker? That’ll cost you. Bump your budget up to £1,049, and you get a much beefier-sounding 2.8GHz processor, while £1,199 will buy you an even faster 3.1GHz Core i5 processor and a Retina 4K display.

Whichever of these you choose, however, the iMac has a positively prehistoric 1TB 5,400rpm HDD. This, if you’re wondering, is the technical term for “very, very slow hard disk”. In fact, this is the first brand-new iMac I’ve used in many years that has felt sluggish straight out of the box. Yes, I’m probably spoilt by the flash storage in my MacBook Pro, but spending an extra £80 on the 1TB Fusion Drive upgrade is an absolutely essential addition. You’ll regret it if you don’t.

And if ludicrous speed is absolutely of the essence, then thankfully there are other options. Alternatively, you can spend another £160 on 256GB of super-fast SSD storage and, if that’s just not good enough, the other upgrades – moving up to a 2TB Fusion Drive or a 512GB SSD – are only available on the range-topping £1,199 Retina 4K model.

Oh, and one other thing: since the 21.5in iMac’s RAM is soldered onto the motherboard, you can’t upgrade it in the future. If there’s the slightest chance that you might need 16GB of the stuff, then decide now or forever hold your, erm, memory capacity. (That’ll be another £160, by the way.)