Speed showdown: Windows 8 vs. OS X Mountain Lion

Windows 8 has reached its "release to manufacturing" (RTM) state, and Apple's Mac OS X Mountain Lion has been out for a couple of months, so now's the time to pit the two new operating systems against each other and find out which is the best in terms of performance.

Even though each OS is in its final state, there are still a few caveats: The tests were run on an Apple laptop, since it's not feasible to install Mountain Lion on anything but Apple hardware. This means that Apple has the advantage of having the OS tuned precisely to the hardware configuration. Windows, by comparison, must run on a huge array of different hardware combinations from many vendors.

I tested by installing 64-bit Windows 8 RTM on a 13in MacBook Pro (a 2012 2.9GHz Core i7 with 8GB of RAM) using Boot Camp. The setup process was pretty smooth, though I'd imagine that not all the Windows hardware drivers were perfectly tuned for the MacBook. Nevertheless, the system was snappy and responsive running Windows 8. And as you'll see in the results, Microsoft's emerging OS can hold its head high on several measures of performance. We'll discuss the tests and benchmark scores afterwards, but first, let's take a look at the full results table:

Mac OS X Mountain Lion Windows 8 RTM
Startup (seconds, lower is better) 26.9 19.6
Shutdown (seconds, lower is better) 5.5 11.9
CD Ripping in iTunes (min:sec – lower is better) 3:42 3:47
Geekbench 2.2 64-bit score (higher is better) 8706 10068
Geekbench 2.2 32-bit score (higher is better) 7918 7549
SunSpider in Firefox 15 (ms, lower is better) 167 158
SunSpider in Safari/IE10 156 105
Mozilla Kraken 1.1 in Firefox 15 (ms, lower is better) 2510 2301
Mozilla Kraken 1.1 in Safari/IE10 (ms, lower is better) 2427 4352
Psychedelic Browsing in Firefox (RPM, higher is better) 1062 5709
Psychedelic Browsing in Safari/IE10 (RPM, higher is better) 3645 7224
Large file folder copy (seconds, smaller is better) 23.2 26.6
*Green cells denote the winner.

Startup and shutdown

One of the most important gauges of speed in a computer is how long it takes to start up and be ready for use. This is probably one of the main reasons the iPad is so successful – it's just there and ready to go, there's no need to wait for a boot process (usually). Not quite as critical, but nevertheless important is the time it takes the computer to shut down. I tested booting up by timing from the click of the disk boot choice to a functional home screen (with no wait spinner still revolving).

For shutdown, I started the timer at the moment of hitting the Shut Down choice, and stopped it when the laptop's fans went silent. I performed a number of test runs for each, throwing out the high and low results and averaging the remaining five. The surprise here is that Windows 8 starts up significantly faster on a MacBook than OS X Mountain Lion does, though the latter shuts down in half the time of Windows 8. But note that hitting the power button puts Windows 8 into sleep mode, which happens pretty much instantly.

iTunes ripping test

A popular app used in both operating systems is Apple's iTunes, and I used this to measure how long ripping a CD (Buena Vista Social Club, to be precise) took in each OS. This test didn't show much difference between the two, with Lion coming in a scant 5 seconds quicker. It took Windows 3 minutes and 47 seconds to rip the 60-minute disc to 256Kbps M4A tracks, while Lion took 3 minutes and 42 seconds. This one is pretty much a wash, though OS X gets a tiny advantage.

Synthetic benchmark: Geekbench

Geekbench 2.3, from Primate Labs, is a cross-platform benchmark that runs a series of geeky tests like prime number, Mandelbrot, blowfish encryption, text compression, image sharpen and blur, and memory stream. The subtests comprise both single and multithreaded applications. The results are normalised so that a score of 1,000 is the score of a Power Mac G5 1.6GHz, so a higher number is better.

I ran both the 32-bit and 64-bit tests in Geekbench three times and took the average for each OS. Though it's mostly designed to test hardware, it can at least show us whether the OS is getting in the way of accessing the hardware quickly. The result for this benchmark surprised me, with Windows 8 in 64-bit mode taking the crown, delivering a score of 10,068 compared with Mountain Lion's 8,706. In the 32-bit version of the test Mountain Lion was actually a bit faster, with a score of 7,918 compared to 7,549 for Windows 8.

Web benchmarks

To test with a few popular web browser benchmarks, I installed Mozilla Firefox on both operating systems so that the browser engine would be less likely to determine the results. But since a case could be made for using the native browser of each OS, I ran the benchmarks in Safari on OS X Mountain Lion and Internet Explorer 10 in Windows 8, too.

The SunSpider JavaScript benchmark is a heavily used measure of a browser's JavaScript performance, put out by the WebKit organisation, which, by the way, makes the rendering engine for Apple's Safari. Results on this test were comparable across all setups, hovering in the high 150s – with one big exception: It was significantly faster on Internet Explorer under Windows 8, which consistently delivered results closer to 100 milliseconds.

Mozilla's Kraken 1.1 is another JavaScript benchmark, which the open-source browser maker claims represents a more realistic workload. Both operating systems were close when running Firefox, with a slight advantage to Windows 8. But when running the native browsers, Windows 8's IE10 fell way behind Mountain Lion's Safari 6.

A final browser benchmark, Psychedelic Browsing, from Microsoft's IE Testdrive site, is designed to test graphics hardware acceleration of web content. Microsoft has done a ton of work on this acceleration technology, and it shows in the above results table, using both Firefox and the native browsers.

File copy test

For this one, I took a folder containing 20 files weighing in at 636MB, and simply timed how long it took to copy it from a fast USB stick to the MacBook running Windows 8 and then Mountain Lion. As when I compared Windows 7 with Windows 8, the operation took a few seconds longer in Windows 8. A Microsoft representative explained to me that this is because "in Windows 8, each file transfer is scanned to ensure there is no malicious code, which takes a little longer but is a better and safer experience for users."

Windows 8 vs. Mountain Lion

This is hardly an exhaustive comparison of every kind of performance measurement available. And indeed with (in most cases) different software running on each, it's hard to make direct, apples-to-apples (if you'll pardon the phrase) comparisons. But the results do show that, say what you like about features and interface, Windows 8 can hold its head high next to Apple's newest desktop operating system when it comes to performance.

In particular, I was impressed with how quickly Windows 8 started up on my test MacBook, and with its remarkably faster Geekbench (64-bit) and SunSpider (in IE10) performances. And anecdotally, Windows 8 feels snappy. Speed is one thing you won't have to worry about with Microsoft's next big operating system.

Mountain Lion, as you'd expect, doesn't feel like any kind of slouch running on a Core i7 MacBook, either. And you could argue that you'd expect the rich environment of OS X to require more processing than the simple, primary-colour interface of Windows 8. This is especially true for startup, which has to load more of the rich operating system's features. Mountain Lion's shutdown time is half that of Windows 8 running on the same machine, and under an independent JavaScript benchmark, Mozilla Kraken, its Safari browser beats Windows 8's IE10. Finally, Mountain Lion's faster file-transfer time will be magnified for truly large amounts of data, too.

For more Mountain Lion and Windows 8 comparisons, read our Windows 8 vs. OS X Mountain Lion head to head, and for deeper dives into the operating systems' features, read our review of Mountain Lion and hands on with Windows 8 RTM.