Using both expanders in HP D2700

Solution 1:

No. What you're asking for is not possible with the HP D2600 and D2700 storage enclosures.

The two controllers (I/O modules) are intended for dual-ported SAS drives and to provide two paths to the disks.

You are oversubscribed when you use a shelf like this. The link is a 4-lane 6Gbps SAS connection (24Gbps)...

If you want more bandwidth, you need to couple SAS SSDs or disks to a RAID controller or SAS HBA solution that can leverage MPIO (or MPxIO).

What are your real throughput requirements? 6 Gigabytes/second seems unrealistic. Plus, a single PCIe 2.0 link is going to cap at 4 Gigabytes/second...

What types of servers/HBAs are involved?

Edit - you're doing this on a Mac. The only way to get the bandwidth you require is to go with PCIe-based SSD, possibly striping across devices. Call FusionIO.