I'll quote myself from the S-ATA/SCSI discussion topic:
[QUOTE=Phunc]"S-ATA II" or "S-ATA 2" doesn't exist. S-ATA is just the type of connection, supporting 1.5Gbit/s or 3.0Gbit/s, optionally with support for NCQ, TCQ, hot-plugging, etc.
"S-ATA II" was the group behind the specs of S-ATA, they named themselves "S-ATA IO" because it was pretty confusing. Since then, most manufacturers and users link "S-ATA II" specs to being 3.0Gbit/s S-ATA, but it is just a spec. Like ATA33, ATA66, etc.