What are you talking about? The SX4 has a DIMM slot as well as a hardware parity engine. It's not as good as a dedicated RAID processor, but it's better than all the software "RAID" cards (including those from Promise) with _no_ onboard RAID processor or memory, and it's cheaper than the 3Ware solutions.

The problem is that the partially-host-dependent implementation doesn't really map well into what we already have support for; hardware RAID cards where the implementation details of the RAID are not exposed to the block driver, and software "RAID" cards which do nothing more than set up arrays in the BIOS and expect the host-based driver to pick up the array configuration stored on the disks, and do all the RAID work on the CPU (most HPT and Promise chips work like this).