Solid state drives are catching on. They’re faster than disk-based storage drives, and more durable too. Unfortunately, they’re also a lot more expensive.

The mid-2010 iMac refresh gives you a solid state drive as a custom option for the 27-inch model, but replacing its 1TB hard drive with a 256MB SSD costs £480, and if you want both, it’s an extra £600.

Apple iMac SSD 2010: Performance

The quad core Intel Core i5 iMac tested here is the top-of-the-range standard configuration, but with a solid state drive added. It’s otherwise-identical to the off-the-shelf release, with 4GB of RAM and an ATI Radeon HD 5750 graphics card with 1GB memory.

In our tests, the iMac starts up in around 25 seconds, which is agreeably speedy but hardly miraculous. Shut-down is almost instantaneous, and applications open incredibly quickly. Most OSX apps were up and running in a couple of seconds, and when we opened iPhoto, iCal, Address Book, Safari and the entire iWork suite simultaneously, all seven Dock icons bounced only once before the screen filled with windows. Very impressive.

Apple iMac SSD 2010: Benchmarking

In our QuickBench benchmarking tests, the SSD’s average random write speeds proved marginally quicker than the HDD’s, but its average random read speeds were almost five times as fast. In the real world, you can expect to spend a lot less time watching OSX’s spinning beach ball as the processor waits for the information it needs.

If you buy a 27-inch iMac without a solid state drive fitted, you can’t add one later; the fixtures required to house it won’t be present. This is unfortunate considering the current high price of solid state storage, which is bound to fall over time. It’s a pity the hard drive bays aren’t user-accessible either.  Changing a hard drive in all Apple notebooks except the air is a simple task, so why do the much heftier 27-inch iMacs’ drives have to be professionally replaced? We hope the next revision will allow end users to perform this task themselves.