iMac With Retina 5K Display Review: Do Those Extra Pixels Really Matter?

By Michael Hession on at

Resolution is often misunderstood. You instinctively know that you want more of it, even when its real utility doesn't live up to the marketing hype. And Apple's new £2,000 iMac has a lot of hype to live up to.

The new iMac's Retina 5K Display seduces your glassy orbs with 14.7 million pixels of pure visual splendour. There's no question about that. But I tried the new desktop computer side-by-side with the previous 27-inch iMac, without a Retina display, to find out whether this monument of resolution is really necessary.

Everything about the new iMac is pretty much the same as last year's 27-inch iMac save that gorgeous screen. Same sleek design, same ports, pretty similar guts. The reason it costs £550 more than the previous one is because of the crazy tech jammed in to allow for the equally crazy pixel count at 5120 x 2880 resolution.

iMac With Retina 5K Display Review: Do Those Extra Pixels Really Matter?

I'm a photographer and video producer, so my daily repertoire is replete with high-resolution content. Digital photo-editing, video, those are usually the prime targets for a high-quality display like this. And for good reason, but I'll get to that in a minute. First, let me tell you what the average computer user — your web-browsing, Spotify-listening, Netflix-watching, word processing Joe or Jane — can get out of the new iMac.

Do you currently own one of Apple's other Retina devices? An iPhone, iPad, or Macbook Pro? Do you remember the feeling of going from the old pre-retina display to the new one? If that experience made an impression on you, chances are you'll be just as delighted upon your first glimpse of the iMac Retina 5K.

In a word, it's crisp. Lines, colours, shapes all appear seamlessly, seeming to float on the surface of the panel. Gone is that barely distinguishable, yet eye-straining jaggedness that characterises text and icons on conventional displays. Text is the biggest beneficiary. Although few people are sitting down in front of their 27-inch displays to slog through War & Peace, reading time accumulates out of the endless stream of blogs, news sites, and social feeds you regularly intake. Getting it done on the Retina 5K Display is a breath of fresh air for your screen-fatigued face.

Here's some text, shot up-close, on the 2013's 27-inch iMac:

iMac With Retina 5K Display Review: Do Those Extra Pixels Really Matter?

And the same text on the Retina 5K display. Click Expand for maximum effect:

iMac With Retina 5K Display Review: Do Those Extra Pixels Really Matter?

Of course, your face generally doesn't sit as close to an iMac display as it does to your phone or tablet. For that reason, the difference doesn't hit you as hard as when the Retina version of Apple's smaller devices debuted. For instance, I don't think many casual computer users would likely notice the difference between the older display and the Retina 5K display without it being pointed out. I had a couple of people in the office check out the display briefly — not side-by-side with the older one, admittedly — and they often said they could barely tell.

The iMac Retina behaves like the Retina Macbook Pro in that it will scale the OS X interface to a readable size while still displaying pictures and video content at its native resolution. That's important, because displaying OS X at the "smallest" setting makes everything, well, very very small.

Personally, I really like the extra screen real-estate and am willing to deal with the tinier interface. It's a huge advantage for me when I'm bouncing between six or seven programs, or working in Photoshop or Premiere Pro when I want to have as many interface elements open as I can. In the case of text, you're definitely stretching the limits of what is readable, and if you don't have great vision, this mode might not suit you. But I just love how expansive my desktop becomes at native resolution.

Here is my desktop with the Retina 5K display scaled to the "best" setting:

iMac With Retina 5K Display Review: Do Those Extra Pixels Really Matter?

And here are the same group of windows with the display set at its max resolution. I did not re-size any of the open apps:

iMac With Retina 5K Display Review: Do Those Extra Pixels Really Matter?


Driving 14.7 million pixels is a task for only an appropriately equipped computer. I tested out the £2,000 base model, which features features a 3.5 GHz Intel Core i5 processor, 8 GB of RAM, and an AMD Radeon R9 M290X with 2 GB of video memory. Performance was a mixed bag.

In general, manoeuvring around OS X with multiple apps open wasn't a problem, but I did run into weird lag in simple tasks like previewing a high-res photo in Finder. The animated expanding window was choppy, not at all smooth, even with no other apps running on the machine. It's a minor thing, but hiccups like this really annoy me, dragging the whole experience down. It's hard to tell which component might be the issue, but it's not the RAM: I popped in an additional 16 GB of memory for a total of 24 GB just to test this out, and image previews still lagged.

iMac With Retina 5K Display Review: Do Those Extra Pixels Really Matter?

My everyday routine involves having at least five Chrome tabs open along with Photoshop, Premiere Pro, Lightroom, Slack, iMessage, and sometimes Spotify. That's a decent load to bear for 8 GB of RAM. And indeed, after a couple of hours things started to feel sluggish.

I also tooled around with some 4K footage shot with a Panasonic FZ1000. These are highly compressed files which should play without a problem in Premiere, which they do. However, when working in Adobe Premiere Pro, don't expect to be able to scrub smoothly across the footage with the £2,000 model. I also tried working with some 4K footage in Final Cut Pro X, where scrubbing was very smooth, thanks to the way Apple optimises their software to sing with its hardware.

It's safe to say that if you are doing heavy multitasking or are serious about content creation, you're going to end up paying a lot more than £2,000 to make the iMac Retina 5K a capable machine. Luckily, Apple does allow users to install their own memory, so do yourself a favour and save lots money by purchasing the base amount of RAM, then getting more from Amazon or Crucial.

Putting 14.7 Million Pixels to Work

Apple markets the Retina 5K Display mostly by showing it as a conduit for high-resolution photos and video. It makes sense: our digital world is composed of increasingly large and beautiful visuals, and display technology has to accommodate that. Right now 4K video is the new hot topic. 4K TVs are flooding the market. Netflix is now streaming select content in 4K. The ultra high-res format is slowly but surely going to replace HD 1080p. For video editors, the Retina 5K display means that you can view and edit 4K video at full-size with enough extra room for your editing interface. That's a nice perk!

In general, I absolutely loved getting to expand my timelines, tool panels, and library windows. Editing photos in Adobe Lightroom was particularly great. With the increased resolution, I'm able to see my photos at their full size without having to zoom in to where I can only see a tiny portion at a time. I can put my face really close to the screen without pixelation distorting my sense of what things look like. Photo-editing was probably my favourite thing to do with the iMac Retina 5K.

On the right is the 2013 iMac, and on the left is the iMac Retina 5K. Both are running Lightroom with an image viewed at full-size:

iMac With Retina 5K Display Review: Do Those Extra Pixels Really Matter?

Here's a macro comparison of from that same image:

iMac With Retina 5K Display Review: Do Those Extra Pixels Really Matter?

But if you are someone simply viewing 4K movies or TV shows, don't expect the new Retina iMac to improve the experience by much.

This is probably the most common misunderstanding about the iMac Retina 5K. Viewing high-res photos and high-res video at full-screen looks almost identical on the Retina 5K vs the previous 27-inch iMac, until you put your face about six inches or less from the screen. Nobody consumes content that way, unless you are a pixel-peeping enthusiast.

Don't get me wrong, images look amazing. Colours are rich, blacks are deep. But the same is true for the previous generation iMac. At the macro level, the difference is stunningly clear, as you can see below. But once you get about half a metre away from the screen, the difference fades to almost nothing.

Watching 4K video, Retina on the left, non-Retina on the right:

iMac With Retina 5K Display Review: Do Those Extra Pixels Really Matter?

Now, what about viewing the regular old HD videos that make up the vast majority of what we watch? On the Retina 5K display, those videos are scaled up an awful lot, so they should appear fuzzier, right? But again, unless you are insanely close to the screen, they look very very similar to the non-Retina iMac. I fired up Netflix and loaded Star Trek: Into Darkness on both the old and new iMacs. After making sure that they were both playing at the highest possible quality, I bounced my eyes back and forth endlessly between the two. I could only detect a very slight softness on the Retina 5K as a result of the scaling, but nothing I would have noticed when leaning back and engaging in what I was watching.

This point bears repeating because in all of the fervour surrounding the new iMac, the endless adjectives spewed about how glorious it is tend to seep into your subconscious, making you see what's not there. Many, many journalists who attended Apple's hands-on following the iMac Retina 5K announcement described the experience as being unlike anything they've ever seen. I'd contend that if they had seen a video or photo on a non-Retina 27-inch iMac right smack up against the iMac Retina, they wouldn't notice as huge a difference.


Everything on your screen just looks incredibly sharp and natural, especially text and elements of the operating system. Content creators will love being able to see more of their work at native resolution, and will benefit from the additional real-estate for interface elements. The system has the refinement and cohesiveness of the iMac, which is still a pleasure to work with. Two grand for the base model seems like a lot, but it's pretty cheap when compared to similarly capable stand-alone displays. Thank god the RAM is user-upgradeable.

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For viewing video content at normal distances, there isn't a huge difference between the Retina 5K and the previous iMac. The base model doesn't have the power to accommodate heavy production tasks, so prepare to pay more. Annoying that only the RAM is user-upgradeable.

Should You Buy It?

The iMac Retina 5K is indeed a stellar display with gobs and gobs of resolution. But the best uses for all that resolution involve working with visual content, not viewing it. It's a computer with a display for editors, designers, and photographers. If you're not one of those things, the sheer pleasure at looking at seamless renderings of text and interface might be enough to lure you in. Or maybe you have a lust for screen real-estate but don't have the space for multiple monitors. If so, it doesn't get better than this. As someone who works with photos and video daily, yes, I really want this thing. But having to go back to last year's iMac doesn't fill me with dread.

If you're in the market for an iMac as a general purpose computer, I would say save the £550, or throw that money into a better spec'd configuration of last year's model. But if you're a content producer looking to go big on a new system, the iMac Retina 5K beckons. You won't regret answering its call.

iMac With Retina 5K Display Review: Do Those Extra Pixels Really Matter?