I hear you, even after writing this I hear you.  Hard drives and backup solutions are not exciting and I totally agree, however, doing a recording job and having a drive fail on you and it costing you money is even duller and more boring. 

I recently was involved with a two day live video and audio recording where such a situation happened. We recorded all the data to a new and tested drive that on the way home from the session died in my bag and when I plugged it in back at the studio I was greeted with the gentle tick, tick ticking of a dead hard drive. Not my finest hour.  

After the dust settled from this job I set about finding a solution that might prevent this issue from raising its ugly head ever again on a location or studio job.  Our friends at OWC were able to help with the Mercury Elite Pro Dual (MEPD) drive solution. 

What's In The Box

The MEPD is a 2 slot hard drive case that you can buy empty, or with OWC's own drives installed. The configurations range from two 1TB drives ($398) up to a massive two 10TB drives ($1480). There is also an option to swap out normal rotational drives for two 2TB SSDs ($550).  The one I have for review has two 2TB 7200rpm spinning drives installed. 

Connectivity

The MEPD is equipped with twin Thunderbolt 2 ports and one USB 3 port so you can hook this thing up to a brand spanking Mac or PC or something a little more vintage remembering that if you use older specification connections you will lose some data transfer performance.

The other connection at the bottom of the rear panel is the connection to the external power supply. I am not a fan of external power supplies or wall warts, however I understand that these can keep the price down and they are also favourable to an internal PSU from a service point of view but, I do get annoyed having to hook an external box that is connected to my computer to its own little external box. 

What's So Special?

Where the MEPD really has the edge over other solutions I looked into is the little dial on the back.  The MEDP can operate in 4 different modes and you set them using said dial. 

IND = Independent - In IND mode the two drives in the MEPD act as totally separate drives. They mount as two drives. They are titled as two and you can format them as two drives. 

In SPAN mode the two drives act as one -  So if you have two 2TB drives installed, in SPAN mode your computer will see just one drive of 4TB. 

In RAID-0  things start to get very clever (well I think it's clever) - In RAID-0 mode the two drives again act as one of 4TB with again only the one drive showing up to the computer. This time the data is spread across the two drives. The benefit of this is that you get increased performance and a faster data transfer rate. The down side is that if one of the drives does fail you loose everything. There is no redundancy in a RAID-0 system. 

RAID-1 mode can also be called mirrored mode - Now the solution I was looking for was the  RAID-1 setting. Again when all is working well the computer only sees one drive but this time it is only 2TB, however, the data is saved to both drives simultaneously meaning that if one drive does die on you then the other can be used to save the day.  

When swapping between any of these modes you have to hold down the SET button under the selection dial to confirm the configuration.  You also have to format the drives which will mean that you will lose any data already stored on the drives.  Do NOT swap drive modes if you have not backed up the contents of the MEPD first. You have been warned.

In operation, the MEPD is very quiet. If there is a fan in there it's a really good one. I have used the MEPD on a number of out of the studio recording sessions and events and it has performed exactly as expected.  I have been recording up to 32 audio tracks at the same time at 192KHz 32 bit and had no issues. The case is solid, well balanced and stylish up to a point and it even comes with USB and Thunderbolt cables.  The front mounted LEDs tell you all you need to know, it just works with no major thrills. Really what more can you ask of a drive array? If you are looking for a flexible and portable storage solution you should take a serious look at the OWC Mercury Elite Pro Dual.