Mercury Accelsior Overview
The Mercury Accelsior is actually a very small device considering its capacity. The drive we received is 480GB, but you can get the Accelsior in 120, 240 and 960GB versions as well. The PCI-E card takes up about half the space as a normal PCI-E would, probably why OWC does include a smaller PCI slot cover with it.
Unlike other PCI-E drives that we have seen that have the actual NAND right on the PCI-E card the Mercury Accelsior has two detachable mPCI-E “blade” drives. Since these “blade” drives are detachable that means you can upgrade this drive for further capacity or if a single drive fails you can easily replace it. These drives are much like OWC’s Mercury Aura Pro SSD’s that are designed for Macbook Pro’s and Air’s. Each drive is powered by a SandForce SF-2281 and includes eight 32GB Micron NAND chips. This gives you a total of 256GB storage for each drive, but because of provisioning used by firmware drives this total usable capacity is dropped down to 240GB, giving you in total for this drive 480GB.
On the main card is a small heatsink under which you will find a Marvell 88SE9230 RAID controller. This controller connects the two attached drives to the PCI-E interface. The drives on the device are set up in a RAID 0 configuration, but that can be changed to RAID 1 if you like. The Marvell controller actually supports up to 4 devices and if we flip the card over we can see where OWC in the future could potentially add 2 more drives.