I've bought a Pro Caddy 2 from TransIntl, for my 2009 Mac Pro 8-core), and I wasn't able to get it working for ages.

When the two drives are separated, I get Read and Write to one drive at around 110mb/sec and Write to the other at 110mb/sec, but Read at about 5mb/sec, which effectively rendered the RAID 0 useless.

The two drives were going into a 1-lane PCIe SATA adapter, I raised a query with the manufacturer, who promptly sent out a replacement PCIe adapter. But the problem was the same.

I now have it working, by having both adapters in my Mac and one drive going into each.

Is there some random configuration that I could change to get it working from one, or would I need a 2-lane PCIe card? I didn't think I would as 1-lane should be able to support 300mb/sec.

...Any suggestions? Thanks