New Alienware M18 Haswell - Poor performance Raid 0 + SSD caching

Hi,

  I recently bought the new Alienware M18 Haswell laptop. I love almost everything about it and hats off to the Alienware design team for the epic evolution, however I have an issue.

The machine ships from the factory with 2x 750GB 7200 HDDs in RAID 0, with a 64GB MSATA SSD caching.
When I run the disk test utility from Blackmagic, I get read and write speeds no more than 70MB/Sec and it really feels like this is the bottleneck in an otherwise stunning machine.

Honestly, I expected more.

I understand that the SSD doesnt contribute to this speed as its a caching thing, but surely the RAID performance on 2 new HDDs should be more, or am I missing something? I recently tested a Scorpio Blue 1TB HDD at 100MB/Sec as a single drive.

I really dont want to fork out for new storage after buying this machine new. Its like buying a Lamborghini from the factory floor, driving it home and replacing the engine. 

Looking forward to hearing any thoughts on this issue and perhaps options.

Mikey