Other World Computing are offering an entry-level solid-state drive, the 30GB Mercury Extreme Pro 3G, as an option for adding SSD speed to targeted uses, such as a boot-only drive, scratch disk or app storage assistant, providing SSD speed for some operations while leaving jobs and storage that require larger capacities to traditional platter-based hard drives or larger SSDs. The company sells kits that allow the drives to replace the optical units on some computers or a Mac Pro hard drive bay.