tl;dr: Make sure you flash an LSI-9211 to IT firmware rev#14 to get it to work with Linux and SSD trim. You may have to downgrade from newer firmware to older firmware to get the card to work.
Finding a SATA III controller with more than one PCI-e lane
After a recent hardware issue I decided to upgrade my computer to use new Intel 520 120MB SSD drives in RAID for improved performance. The motherboard I use (an ASUS Rampage III extreme) has a Marvel SATA III controller with two ports, but I discovered that it is connected via only a single PCI-e lane (each lane can do at most 400MB/sec*). This means that it can't effectively support even a single Intel 520 because one device can saturate the SATA III bus (An Intel 520 is rated at up to 550MB/sec sequential write).
So I went on a quest for a new SATA 3 controller. To Frys! I exclaimed. But unfortunately, all the PCI-e 2.x SATA III …