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imac

Seeking clarity in Retina iMac desktop images

I’ll admit it: I’m a desktop image (nee wallpaper) addict. I love to use a wide variety of images, and change them often throughout the day, just to keep my work environment fresh. On my two external displays, I use iPhoto images—general photos on one, kid pictures on the other. But for the main iMac screen, I prefer to use photos taken by others—typically stunning landscapes and cityscapes from all over the world.

With the arrival of my 5K iMac, however, my existing collection was no longer sufficient. Yes, they were all 2560×1440 images, which matches the “apparent” resolution of the Retina iMac. But in order to make that image fill the Retina iMac’s screen, it’s first scaled up to 5120×2880, then displayed by OS X at 2560×1440. As a result, my desktop images aren’t nearly as sharp looking as they were on my old 27″ iMac’s display.

As an example, here’s a segment of two versions (2560×1440 and 5120×2880) of the Sydney Skyline, as screen-captured when set as my Retina iMac’s desktop picture. As you move the divider bar right, you’re revealing more of the 2560px version; move it left, and the 5120px version takes over.

After scrolling back and forth a bit, you might be thinking these pictures are identical, and I’m just seeing things. While I may be seeing things, the pictures are not identical. (Compare some closely-spaced lights and the crispness of vertical lines in each image to spot the differences.)

Read on for a closer look at the image, which really shows what you’re losing by using a 2560x1440px desktop image on a Retina Mac…as well as a list of places I’ve found that have 5120x2880px images available.

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A very quick look at the Retina iMac’s graphics performance

While I’m still busy setting up my Retina iMac—given I always do this by hand, it’s time consuming—I did take a few minutes to see how the graphics performance compares to that of my mid-2011 iMac.

To test the Macs, I use a visual benchmark called Unigine Valley. This benchmark puts the graphics card through a real workout, and is fun to watch while running. Before the results, here’s a quick comparison of my two iMacs:

2011 iMac 2014 iMac
CPU 3.4GHz Core i7 4.0GHz Core i7
RAM 16GB 24GB
Graphics AMD HD 6970M AMD R9 M295X
VRAM 2GB 4GB

And here’s how they did…

2011 iMac

2014 iMac

I’m no math whiz, but it looks like the new Retina iMac is over twice as fast in the graphics realm as my older machine. I knew it’d be faster, of course, but I wasn’t expecting that kind of speed up. Wow.

How I configured my 5K TV with bundled computer

After seeing the new iMac with Retina 5K display (I’m just going to call it a Retina iMac from here on out, or even riMac for short), I decided it was time to upgrade my aging but still oh-so-functional mid-2011 27″ iMac.

For those contemplating the same upgrade, you may be mulling decisions on processor, RAM, storage, and graphics cards; here’s the logic behind each of my choices in those areas, in case it helps you with your decision.

CPU

This was the simplest decision to make—I always buy the most powerful CPU I can afford. In the case where the choice is a Core i5 vs. Core i7, I will always go for the Core i7. That’s because only the Core i7 supports hyper threading, which, as Apple writes, is “a technology that allows two threads to run simultaneously on each core. So a quad-core iMac has eight virtual cores, all of which are recognized by OS X. This enables the processor to deliver faster performance by spreading tasks more evenly across a greater number of cores.”

In addition, by upgrading the CPU, I make the machine more usable many years down the road—whether for my own use, or when reselling to someone else.

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My iMac’s literal bug

Another lost-to-Google-policies Tweet movie; this time, about a bug in my iMac that was lingering after 24 full hours.

The bug, of course, was a real one; here’s the video that’s vanished from the above tweet:

Thankfully, the little buggy vanished not soon thereafter, thankfully not remaining onscreen for eternity.

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