Lately, I've been struggling with what's clearly a first-world problem: I have too many computers.

There was my main iMac, which I love. Then there was my "power" laptop, a mid-2010 15-inch MacBook Pro (with the 1680-by-1050 display and a recently installed 750GB SSD), which I love. And there was my "light" laptop, a mid-2012 11-inch MacBook Air, which I love (and which replaced an older 11-inch Air). So what was the problem?

The problem was that I don't travel often enough to justify owning two laptops. And even if I did, I'd still be stuck answering the "Which one should I take on this trip?" question. Generally, I take the big heavy MacBook Pro beast when I need the extra screen-space and the more powerful (or so I thought) CPU; when I don't need those two things, I take the Air. And then I also have to deal with the issue of which machine has the files I need for each trip. In short, it was a horrid setup, and it needed fixing.

My proposed solution: Sell both of the old laptops, and replace them with one that provides a large pixel count, light weight, and powerful CPU, yet is still small enough to fit in most any bag I want to take on a trip. And this being the real world, I needed to keep the total cost under $2,000.

The contenders

In my search for a replacement laptop, I considered both the MacBook Air and the MacBook Pro lines.

Given that I'd already tried an 11-inch Air and found its screen-size wanting for some tasks, that model was quickly ruled out.

The 15-inch Retina MacBook Pro was tempting, but I hit a few deal-breakers. First, the weight: At 4.5 pounds, it's a pound lighter than its 2010 predecessor, but fully three pounds heavier than the 11-inch Air. That's a huge difference. Second, the size: You can only make a package so small if it's got to hold a 15-inch display. Third, the cost: With my $2,000 budget limit, I'd only be able to afford the entry-level Pro, and I wasn't sure its 256GB of drive space would be sufficient for my needs.

So that left only two models to consider: the 13-inch MacBook Air and the 13-inch Retina MacBook Pro. I went back and forth between these two models quite a bit; one day, I spent enough time at my local Apple Store that I think I spoke to every single employee there. The Air was tempting for its light weight (just under three pounds, versus about three-and-a-half for the Pro), the Pro for its faster graphics and more powerful CPU. Back and forth I went, like some overly anxious father-to-be pacing the delivery room.

The screen question

With the Air, I was concerned that I wouldn't find the 1440-by-900 display roomy enough, especially not after the 1680-by-1050 MacBook Pro screen I was accustomed to. I didn't have that concern with the Retina MacBook Pro.

Why didn't I care? Because I intended to take advantage of OS X's "scaled" displays option, which lets the display act as though it has either 1440 by 900 or 1680 by 1050 pixels of resolution. That last setting would give me the same pixel count as my old 15-inch MacBook Pro, yet bundled in a tidy 13-inch package. So I spent a lot of time looking at the screen while running it at 1680 by 1050 (as well as time using it in Retina mode); it seemed fine for my eyes.

In addition to the resolution differences, a 13-inch MacBook Air configured with upgraded RAM and storage space (and with the faster CPU) was only $150 less than an equivalent 13-inch Retina MacBook Pro. For that extra $150, I'd get better graphics (Intel Iris versus Intel HD Graphics), and a notably faster CPU (a 2.8GHz Core i7 versus a 1.7GHz Core i7).

The decision

So that was that: I made my decision, and purchased the $1,999 13-inch Retina MacBook Pro, equipped with the 2.8GHz Core i7, 8GB of RAM, and 512GB of PCIe-based Flash storage. (The Apple Store even had that unit in stock, which surprised me; the online store showed that it would only be available as a build-to-order.)

Once I got the new machine home, I was curious to see how it compared to the two laptops it'd be replacing in terms of size, screen, and performance.

I started with the basics: comparing the dimensions and specifications (RAM, CPU, and so on). Just for fun, I also included my mid-2011 iMac in the mix, though I didn't bother with its dimensions.

One observation is that although all four machines have Core i7 processors, those are all very different CPUs, each from a different generation of Intel processors. As you'll see, that differences are reflected in performance.

Dimensionally, I'll be carrying an extra pound (and a few inches of size) over my Air, but saving over two pounds (and many inches of size) from those times I traveled with the MacBook Pro. When the laptops are stacked one atop the other, the size differences become apparent.

Obviously, the 13-inch is somewhat larger than the 11-inch Air, but not as much as I might have expected (only half an inch wider and just over an inch deeper). When compared to the 15-inch MacBook Pro, the 13-inch Retina is simply tiny. Those tidy dimensions should make it reasonably easy to use in the airlines' coach sections, where I'm usually stuffed on my trips.

Given that one of my main goals was to preserve the 1680-by-1050 pixel count of my 15-inch MacBook Pro, I love that I can run the 13-inch Retina MacBook Pro at that identical (though simulated) resolution. The pixels are definitely denser than on my 15-inch machine, but I've found that (even with my aging eyes) I can use it quite well: Certain websites have to be hit with Command-Plus (increase size) a few times, but I love how much more space I have when compared to using the machine in Retina mode.

When my eyes are feeling tired, I can use the in-between 1440-by-900 setting; when they're really tired, or I want to do a lot of reading or just easy Web browsing, I can set the machine back to Retina mode.

Just because it's possible, I installed Display Menu, which lets you access the full native resolution (2560 by 1600) of the display. While things were visible on the screen, unless you've got 20/10 vision, you would not want to work at this resolution for any length of time. But it was still an impressive demonstration.

One area of concern about using the "more space" modes is the warning you get when scaling resolutions in System Preferences panel, to the effect that using scaled resolution may affect performance. This only makes sense: the computer must work to create a resolution that doesn't exist natively on the display. But how much of a performance hit would I take for that?

Performance testing

To answer that question, and others about general performance changes over the years, I ran a number of benchmarks to test the disk, CPU, graphics, and overall performance of the new Mac as well as the two machines it'd be replacing (and, again, the iMac as a point of comparison).

I used an odd assortment of tools in my benchmarking--some of them well-known (Xbench, Cinebench), others less so (gpuTest, Unigine Valley). I don't pretend to be a professional benchmarker. I didn't test these machines in a controlled environment, and I didn't spend days at it.

Rather, I kept things simple: I created a new user on each machine (to make sure it wasn't running any of my usual add-ons), then rebooted the machine, logged into the new user account, and ran each benchmark twice, and averaged the results. I ran resolution-dependent tests (GpuTest, Unigine Valley, and portions of Xbench) at both Retina and the 1680-by-1050 resolution setting on the new Retina MacBook Pro; I also ran the GpuTest and Unigine Valley tests in an 1152-by-720 window--the largest I could fit on the 11-inch Air.

The results of the tests:

Some interesting tidbits that I found in my testing:

PCIe-Flash "hard drives" are incredibly fast. The 13-inch Retina MacBook Pro was miles ahead of both other Macs, which are using SSDs.

Core i7 performance continues to improve. The Haswell-generation Core i7 in the new Retina MacBook Pro is roughly 30 to 60 percent faster (depending on the test) than the Arrandale version in the 2010 MacBook Pro; it's also 15 to 30 percent faster than the Ivy Bridge version in the 2012 MacBook Air.

My "power" MacBook Pro isn't so powerful. While I knew it was aging, and I knew it'd get trounced by the Retina machine, I was quite surprised to find that the 11-inch MacBook Air also crushed the MacBook Pro in nearly every test--despite the Pro's 2.66GHz CPU and discrete video card versus the Air's 2.0GHz CPU and onboard video.

Laptop graphics have come a long way. The new 13-inch Retina machine is miles ahead of the other laptops in graphics performance. When used at Retina resolution, its frames per second rate on most tests was roughly twice that of the other laptops--even when working in identically-sized windows.

Still, laptops aren't graphics powerhouses. While the new machine's graphics performance is impressive compared to its predecessors, it's nothing compared to a nearly three-year-old iMac. That iMac is at the top of the charts in all graphics tests.

Scaled mode does cause a hit in performance. Both the Unigine Valley and GpuTest tests showed a dramatic fall-off in graphics performance when running at 1680 by 1050. Not only are there more pixels to move around during the tests, but those pixels are simulated, causing the machine to work harder.

That's the bad news. The good news is that, even with the reduced performance, the new machine is still graphically faster than either of my previous laptops. (The 11-inch Air did beat the 13-inch Retina by one frame per second in the GpuTest, but that's basically a wash.)

The even better news is that this fall-off isn't seen when doing normal stuff like working with Finder and apps; there was only a minimal drop-off for both Xbench's Quartz and UI scores in the 1680-by-1050 mode. So as long as I'm not using the machine for OpenGL work or gaming, there's little impact on day-to-day use.

Wrapping it up

I've had my 13-inch Retina MacBook Pro for a couple months now, and it's turned out to be an ideal replacement for my previous two laptops. For a slight increase in size and weight over the 2012 11-inch MacBook Air, I've gained a much faster machine with not only a physically larger screen, but more pixels on that screen (even in Retina mode).

The real revelation to me is how much of a different four years makes in computing power. While my 2010 laptop is still quite functional, technical advancements in CPUs, graphics chips, storage, batteries, hardware design, and displays have rendered it something of a dinosaur.

The only advantage that older machine offers over my new one is its larger display--and if I'd been willing to spend more money and carry more weight, I could have had that as well, via the 15-inch Retina MacBook Pro.

For my needs, though, the 13-inch Retina MacBook Pro appears to be the ideal do-it-all laptop. So, anyone out there need a dinosaur?