James & Stan, > > Since your CAP.ISS is set to 0010(3Gbps), most likely you'll > > have to ask your BIOS vendor to enable 6Gbps in one release. > > Some BIOS vendors may set the max speed to Gen2 to save power. > > Unless you have a PMP on the other end of that SATA link with a bunch > of > striped drives, or an expensive SSD, you won't notice a performance > difference between 3 Gb/s and 6 Gb/s link speed anyway: no single mech > drive on the planet can come close to pushing 300 MB/s let alone 600. > The fastest 15k SAS drives are peaking at around 200 MB/s IIRC. And > there are few [affordable] SSDs that will saturate a SATA II link, let > alone a SATA III link. > > My advice, FWIW, is to simply ignore this, unless you plan on attaching > a device in the near future that can actually exceed 300 MB/s. > Currently the only way to do this is with striped mech drives on a PMP, > or with a $500+ SSD. There is one RW bit in SB800 which makes SATA controller operate in maximum Gen2 (3.0Gbps), this bit will limit CAP.ISS(RO) to 0010(3Gbps). Some BIOS vendors may enable this bit "to save more power"(from spec, driver needs not touch it). That's why I suggested James contact BIOS vendor if you do want to get the 6Gbps dmesg. Thanks, Shane -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
