Do RHEL6 Storage Admin Guide comments about using RAID with SSDs apply to hardware RAID?

Issue

• We're planning to purchase and roll out a bunch of new servers loaded up with solid-state disks in hardware-raid configurations and want to get some definitive answers from Red Hat regarding the statements below from the RHEL 6 Storage Administration Guide, i.e., does any of it apply to hardware raid?

  In addition, keep in mind that MD (software raid) does not support discards. In contrast, the logical volume manager (LVM) and the device-mapper (DM) targets that LVM uses do support discards. The only DM targets that do not support discards are dm-snapshot, dm-crypt, and dm-raid45. Discard support for the dm-mirror was added in Red Hat Enterprise Linux 6.1.

  Red Hat also warns that software RAID levels 1, 4, 5, and 6 are not recommended for use on SSDs. During the initialization stage of these RAID levels, some RAID management utilities (such as mdadm) write to all of the blocks on the storage device to ensure that checksums operate properly. This will cause the performance of the SSD to degrade quickly.