Amazing display, high performance across the board, excellent graphics performance, excellent design
Good value for the tech but still expensive in current all-in-one market, can't be used in Target Display Mode, software required to take full advantage of 5K display
Nigel Tufnel put it best in This Is Spinal Tap: "The numbers all go to eleven. Most blokes will be playing at ten but where can you go from there?" Eleven is "one louder" than the competition.
Amidst a loudening concert of hardware companies singing the praises of consumer-facing 4K televisions and desktop displays, Apple's new iMac has a 5K display -- the computing equivalent of "one louder".
Despite Tufnel's famously stubborn insistence that having an eleventh volume level on a guitar amplifier was better than just making ten a bit louder, Apple's extra pixels have practical and measurable benefits. Whether they're worth the entry-level starting price of a pound under £2,000 really depends on what you intend to do with them.
Hardware
A regular 27-inch iMac has a resolution of 2,560x1,440 pixels on its IPS display -- higher than HD, but precisely half the Retina iMac's 5,120x2,880-pixel resolution. To say it makes no difference is to say a rock band sounds no better with their amps turned up to their max (ten or eleven, depending on the ego of the guitarist).
It makes a huge difference, like the jump from a non-Retina iPad to the new iPad Air.
The iPad Air has a pixel density of 264 pixels per inch; the Retina display iMac has a pixel density of 217 pixels per inch (or 217.57 to use the precise result of our calculation). To the eye, it's so close it's hard to argue there's a significant difference.
It's also near identical to the 15-inch MacBook Pro's Retina display, which counts 220 pixels per inch.
Prime targets here are video and photo editors -- this reviewer included. Images have looked this good before (on an iPad Air) but never this good on such a large screen. The tinniest details of massive, complex images can be picked out without the need to zoom in or use a digital loupe. Viewing angles of the IPS screen are so wide it's great for photographers needing to show clients their work without having the "hey, you take my seat here in front of the system" conversation.
On the video side the same is true, plus Full HD video can be confined to just a small part of the screen, making multi-cam film editing possible without sacrificing detail of additional angles.
More impressive, it made having a single 4K video editable at its native resolution without losing Final Cut Pro X's timeline. We safely queued up several 4K clips on the imeline and could scrub through them left and right without any lag or system slow-down. It reminded us of testing Apple's latest Mac Pro desktops, which got us thinking: how do they compare power-wise?
Performance
Inside our review unit was a quad-core Intel i7 CPU running at 4GHz with 8GB of 1,600MHz DDR3 RAM (up to 32GB is supported) and an AMD Radeon R9 M295X graphics chip, which itself offers 4GB of its own video memory (a lower-spec Core i5 / M290X is also available, which is less geared up for professional media handling). Fellow hardware geeks may already have recognised something interesting about that choice of graphics processor: despite the 5K display, that's a mobile GPU on the inside. These are better for battery life in portable systems but generally don't offer as high a clock speed as a desktop equivalent.
But a desktop this most definitely is, and AMD's chip features a bunch of exciting technology to make this an extremely capable performer. Inside Apple's iMac it was able to handle all the real-world 4K and HD video editing we threw at it in Final Cut Pro.
It was also competent at handling 3D games such as Borderlands 2 and BioShock Infinite.
Or was it?
Apple does something clever with its Retina display tech on iMacs and MacBook Pros. Because of this machine's 5,120x2,880-pixel resolution, a 27-inch screen means without some software trickery icons and text are going to be minuscule on the screen. To compensate, OS X Yosemite makes them larger by rendering them with additional pixels. This is what gives them such a crisp, beautiful aesthetic. With gaming, this happens too but it forces the machine to render them at a lower resolution and then blow them up to full-screen -- in real-time, this hits the performance of games running with intense 3D sequences.
Here's the great bit though: we downloaded SwitchResX from the App Store, which lets you switch the 5K display into a mode that lets you take advantage of the entire 5,120x2,880-pixel panel. This is how we could edit 4K videos and still keep the timeline visible, and it also means games -- such as the aforementioned BioShock Infinite -- could be told to run at 5K resolutions. And in our testing it ran it pretty well.
This is not a gaming rig by any means, but there is a huge amount of powe on offer from the AMD GPU. BioShock Infinite was pulling between 15-30 frames per second with graphics settings set to "high". That's impressive at 5K. Playing games at the iMac's native resolution also means none of that pixel-doubling needs to take place, so textures are unaffected. At these high resolutions they are therefore much smoother and crisper.
Graphics-wise the Retina iMac is actually a better choice for OS X-based gaming than the Mac Pro. Despite the latter having two GPUs, under OS X only one of them can be used to render games -- you need to install Windows to take advantage of AMD's Crossfire configurations that blend the power of two GPUs into one "super GPU". We saw this when testing the Mac Pro and noted almost exactly double the performance of Borderlands 2 run under Windows versus OS X.
But that's not where the comparison to the Mac Pro ends.
Something interesting happened during our raw power benchmarking with the GeekBench 3 application: the Retina iMac scored 16,405. On its own, not that interesting. That is until we checked our score for the Mac Pro and noted we had seen it score 14,540.
That can't be right, can it? The powerhouse that is the Mac Pro scored LESS than the all-in-one Retina iMac? We checked our original benchmark logs and there it was again: a higher score for the iMac versus the Mac Pro.
For clarity, this is the high-end iMac and that was the very entry level Mac Pro, with a 3.7GHz Intel Xeon CPU packed with four cores. That machine is configurable to house as many as 12 cores running at 2.7GHz each, with 64GB of RAM and 12GB of GPU RAM spread across a pair of AMD graphics chips designed for workstations. It can power multiple 4K monitors at once and manage far more raw data in parallel than the iMac.
Conclusion
If there was ever a headline waiting to be written it was "Retina iMac more powerful than Mac Pro". But that would be for shock value. The truth is that they offer different strengths to different people, but the Retina iMac is nonetheless a monster of a system with power that crosses the border into what you would expect from a basic professional workstation. And it does that for a hair under two grand with a 5K monitor to boot. That's excellent value that Apple's competitors will find hard to copy.
At the moment it's hard to advise the average user shopping for an all-in-one fork out the extra cash for the Retina model, because unless you're working with photos and videos the benefits will be too costly to justify for simple web browsing and email. Likewise, if gaming is your calling a Windows box will cost you less and offer you more options when it comes to software.
As a sign of what's to come the Retina iMac is one of the most exciting desktop releases in a long time. Today, it's a superb choice for photographers and video editors; tomorrow, the inevitable drop in price will make the iMac a class of system that will have competitors scrabbling to catch up.
This article was originally published by WIRED UK
