Retina 5K iMac: Powerful Proof of the PC Renaissance

He reached for an analogy. "When we were an agrarian nation, all cars were trucks, because that's what you needed on the farm," Mr. Jobs said. But as farming died off and people in urban areas began to buy automobiles, the auto market split into distinct categories. There were easy to use, relatively maintenance-free cars for everyday drivers, and powerful, specialty vehicles like trucks for people who needed to get stuff done. Laptops and desktops "are going to be like trucks," Mr. Jobs predicted. "They're still going to be around. They're still going to have a lot of value. But they're going to be used by one out of x people."

Four years later, Mr. Jobs's predictions have pretty much panned out. Benedict Evans, an analyst at the venture capital firm Andreessen Horowitz, estimates that the number of smartphones and tablets in use around the world surpassed two billion in 2014, eclipsing the number of laptops and desktops in use. But just as Mr. Jobs argued, the rise of mobile devices has not led to the death of desktops and laptops. In 2014 the once-sharp decline in PC sales began to level off. In some ways this year was a renaissance for the personal computer as our laptops and desktops acquired fantastic new powers that made them better than ever.

We saw the rise of Chromebooks, the Google-powered laptops that run an operating system based on the Chrome web browser, which often sell for around $200. Because they're inexpensive and easy to maintain, Chromebooks began to cut into the low end of the computer market in 2014, and they've proved especially popular in education, where teachers and parents appreciate their simple design.

Responding to the potential threat posed by Chromebooks, Microsoft released a version of its Windows operating system that manufacturers began to include in inexpensive machines. Hewlett-Packard, for instance, released the Stream 11, a Windows laptop that sells for $200 and comes with a free subscription to Microsoft Office apps and one terabyte of online storage.

You can think of Chromebooks, inexpensive Windows machines, mobile phones and tablets as the cars of the tech business. And this year, low-priced Chromebooks and Windows machines helped the PC industry hold steady against the rise of phones.

But there's a question of long-term viability. How long can PC makers survive by selling cut-rate devices?

Enter Apple and the new iMac it unveiled in the fall, an expensive desktop with a beautiful, high-resolution screen. If Chromebooks are cars, the new iMac is the world's best truck. It's a device optimized for professionals, not casual users, and it blazes a path forward for the once-beleaguered PC industry.

As phones and tablets become more powerful and useful, and as they begin to occupy more of our time, PC manufacturers will have to create computers that take advantage of PCs' shape, size and power. They'll have to find new features that can't be mimicked by smartphones. With a display unmatched by any other computing device you can buy today, the new iMac does just that. That's why, of the dozens of new tech devices I tried this year, it was my favorite. Playing the high end has proved lucrative for Apple. In the third quarter of 2014, by the research firm IDC's estimates, Apple became the fifth-largest PC seller in the world. Though its market share is dwarfed by the Windows PC giants Lenovo, Hewlett-Packard, Dell and Acer, Apple is predicted to rake in about half of the PC industry's profits. "They're doing remarkably well, and I think they'll continue to go up," said Tom Mainelli, who studies the PC market for IDC.

Mr. Mainelli argued that the ubiquity of smartphones had increased the appeal of Macs. Because people are shifting more of their computing to mobile devices, they're waiting longer to replace their PCs. The longer ownership period helps people justify buying Apple's high-end machines. "Consumers are saying, 'Well, if I'm going to hold on to this thing for five years, I should buy a good one,' " Mr. Mainelli said. "Apple has really benefited from that."

The new iMac has a 27-inch, Retina 5K display, meaning that its screen has about 5,000 lines of resolution horizontally and nearly 15 million pixels across the entire display. That's about seven times as many as you'd find on a high-definition television set — and a few million more on than the latest ultra-high-definition TVs.

All those pixels make for a luxuriously sharp picture. Text sparkles and images pop, and when you to switch back to a computer with a normal screen, your eyes beg you to reconsider. At least, mine did. Years of staring at bad screens has turned my eyes into ruined orbs, but now, finally, I'd encountered a computer display that was good to them. When it was time to return the review model that Apple sent me, I hated to part with it. So I did something crazy: I bought a Retina 5K iMac of my own.

These machines aren't cheap. The Retina 5K iMac starts at $2,500, which is $700 more than the non-Retina 27-inch iMac, and thousands more than you'd pay for a run-of-the-mill desktop computer. Still, for what you get, it's not all that much. Last year Dell introduced a stand-alone 5K monitor that it planned to sell for $2,500 — the same price as Apple's entire computer, for just the screen. Shortly after the iMac was announced, Dell reduced the price of its display to $2,000. But when you pair that display with a computer powerful enough to handle it, you're bound to spend more than what you'll pay for Apple's all-in-one machine. If you're looking for a desktop with a screen this good, Apple's desktop is the way to go.

Apple is unlikely to sell the new iMac in high volumes. It's a computer intended specifically for a small niche audience of photographers, video editors, animators, digital producers and Web-addled writers like me — people who spend a lot of time on their machines and are willing to pay for high-end tools.

Still, even if Apple doesn't sell millions, the new iMac is an object lesson. If you're a casual computer user — looking only to surf the web, check email and do other light tasks — you don't need much more than a Chromebook or a tablet these days. You could probably get by with just a phone.

But as the low end of the PC business is swallowed by cheap devices, the only people left in the market for traditional PCs will be professionals. Apple's recent success shows that professionals still love PCs, and they'll even pay large sums for them. Some people will always need trucks.