Mac Pro Westmere Internal SATA Bandwidth
The 2010 Mac Pro motherboard still has a maximum bandwidth of around 690MB/sec for internal SATA ports, as shown below (I’ve previously tested with up to 4 SSDs in the 2009 model).
Using DiskTester, I tested a RAID-0 stripe of 3 X 200GB OWC Mercury Pro RE solid state drives. That configuration ought to reach speeds of about 840MB/sec for reads, and 780MB/sec writes, if scalability were perfect.
The actual speed figures shown below are not so high, because the Mac Pro SATA ports share a maximum bandwidth limitation.
Since two SSDs are good for about 510MB/sec reads and 470MB/sec writes (as actually measured), the improvement with three of them is not as impressive as one might hope.
Still, there’s no denying that even two SSDs offer a level of performance that outstrips the ability of most programs to use it. Using three SSDs is a smart move for anyone working with programs like PTGui.