The original Western Digital Scorpio Blue 1TB was 12.5mm thin, which was once the standard thickness of 2.5in drives. With the advent of leaner and leaner laptops, that size often doesn't fit anymore. The new Scorpio Blue 1TB measures in at 9.5mm, which does make it suitable for most current laptops. It's true that many models are now even 7mm thick, but as of yet that is still a minority.
If you wonder how Western Digital has accomplished this, they did it by completely overhauling the interior of their devices. The original Scorpio Blue 1TB had three internal platters, and the new version has only two, with 500GB each. That also means that it has a higher data density. 500GB is currently the highest capacity available for 2.5in platters.
We will see later on that the higher data-density makes the Scorpio Blue 1TB quite a bit faster than its predecessor. It's still a 5400 RPM drive, and for real performance you still need a 7200 RPM drive, and these don't exist yet. Okay, there's one, the 1TB Seagate Constellation.2 2.5" 7200 RPM disk, but it's intended purely for servers.
The new 9.5mm Scorpio Blue 1TB costs an average of £119; the old 12.5mm one is £97. The price per gigabyte is not bad at all.
The most important test remains PCMark Vantage which gives a score for real world performance by running simulations of hard drive activity for real programmes. The total score is the most interesting of course, but PCMark Vantage has some useful subscores as well, for example for gaming and starting up Windows.
PCMark 7, which gives realistic scores for the Windows 7 era, was not available when we did our last large-scale comparison test of hard drives. We have tested a few 1TB drives, including the popular Samsung Spinpoint F3, but there is far less comparison material there. You can read the rest of Western Digital Scorpio 1TB (9.5mm) preview on Hardware.info.