The new Expert Reviews benchmarks, which can be downloaded for free, are designed to be run natively on Windows 7, Ubuntu 10.10 (a Linux distribution) and Mac OS X, so we decided to find out which operating system is the fastest.

We installed all three operating systems onto a 27in iMac with a 128GB SSD and a quad-core Intel Core i5-760 processor. The 64-bit versions of the operating systems were installed each time, and we used Bootcamp to load both Ubuntu and Windows 7 onto the iMac. All scores are recorded in seconds and normalised against a PC with an Intel Core i5-2500k processor running Windows 7. This PC scores 100 in each test.

Image Editing

Our image editing test uses the ImageMagick command-line Convert tool to change 24-bit TIFF files to PNG format. It runs with the auto-level, auto-gamma, antialias and contrast options, simulating common operations performed on image files.

As you can see from the graphs, Ubuntu 10.10 is the stand-out performer in this test. Its score of 102 is faster than our reference Core i5-2500K-based PC running Windows 7. We suspect that this performance is due to the fast ext4 file system that the OS uses. Windows 7 is the second fastest, with Mac OS X bringing up the rear in last place.

Video Editing

Our video editing test uses Handbrake to convert a 1080p, 50fps AVCHD video file to iPhone 4 format. This test is multi-threaded and the number of cores a processor has makes a big difference to the conversion speed.

In this test, the differences between the operating systems is smaller, as the processor speed is the real decider for this test. Even so, there are some differences. Ubuntu 10.10 is, once again, the fastest, but Windows 7 is a close second. Mac OS X comes in last again, a way behind the other two.

Multi-tasking

Our multi-tasking test runs the video and image-editing tests together, plus it uses Mplayer to play the AVCHD file at the same time.

Ubuntu 10.10 loses its lead here, dropping a fair way behind Windows 7 and Mac OS X, which produced the same score. The Linux distribution really struggled with this test and we suspect that less-mature AMD graphics drivers are to blame for the performance hit when playing our AVCHD test file.

Overall performance

All results are normalised against our reference Core i5-2500K PC, which scores 100 in all tests. Finally, we calculate an overall score by using a weighted average (3 for multi-tasking, 2 for video editing, 1 for image editing). This, surprisingly, compresses the results, giving Ubuntu 10.10 and Windows 7 the same overall score, while Mac OS X is just a couple of points slower.

Ubuntu is by far the fastest OS in our tests, until multi-tasking is brought into the picture, where it becomes a lot slower. Windows 7 isn't too far behind, but is better at multi-tasking; and the same goes for Mac OS X. In general, it appears that Mac OS X holds back some system resources, making the OS feel more responsive under heavy load, but reducing performance slightly for the rest of the time.