How can you improve on OCZ Technology’s original RevoDrive (reviewed November 2010), which binds two SandForce SF-1200 SSDs to a PCI-E card? You add another two SSDs for a quad-drive SSD. That’s what OCZ did for the RevoDrive X2.

The original RevoDrive topped out at 500MB/s in very specific tests, and hovered around half that speed for most day-to-day usage, which still put it at the very top end of current-gen solid-state devices. OCZ claims the RevoDrive X2 can hit speeds up to 750MMB/s—that’s marketing megabytes per second. Oh yeah, we’re testing that.

It’s been nearly two years since we saw the first 2TB drives hit the market. You’d think we would have gotten 3TB drives months ago. It’s not that hard, is it? Turns out, it’s pretty complicated. We’ll get into all that in a second, but in the meantime, here’s what you need to know: Western Digital’s new 3TB Caviar Green drive is the first internal bootable 3TB drive to hit the market. It’s not the first 3TB drive—Western Digital and Seagate both have external versions—but it is the first bootable 3TB drive.

So, why are we only now seeing bootable 3TB drives? Because most computers are running on kludged-together legacy systems, that’s why! Hard drives have historically been divided into 512-bit sectors. Your drive’s master boot record, which tells the BIOS where everything is on a given drive, is 32-bit, so it can only address a number of sectors equal to one 32-bit integer’s worth. Two to the 32nd power is 4,294,967,296; multiply that by 512 bytes and you get 2.19TB, which is how big a partition can be before the MBR runs out of room to figure out where everything is. To overcome this obstacle, your PC needs to meet a laundry list of requirements: It needs a 64-bit OS, a motherboard that supports UEFI (the successor to the BIOS), and support for GPT partitions rather than MBR.