On Wed, Jun 19, 2013 at 09:16:35AM -0700 I heard the voice of Jeremy Chadwick, and lo! it spake thus: > > The above CDB + subcommand disables APM entirely. There is a lot > more to APM than just parking heads (and in all honesty, APM should > have nothing to do with parking heads). Disabling APM can actually > have drastic effects on drive temperature (meaning there are certain > chip and/or motor operations that said feature controls *in > addition* to head parking), and other firmware-level features that > aren't documented.
True enough, in concept. With all the drives sitting behind ventilation perfectly capable of dealing with 15kRPM drives, I don't worry about what that might do to the 7200's though... > Furthermore, that CDB does not work for all drives. There are > Seagate drives -- I know because I bought some and returned them > when the APM trick did not work -- that lack the LCC-disable tie-in > to APM. The drive either rejected the CDB (ATA status code error > returned), while others accepted it but nothing in 0xec (IDENTIFY) > reported as got changed. Well, I haven't seen it with these. Several of ada0: <ST1000DM003-9YN162 CC4D> ATA-8 SATA 3.x device and some systems with CC4C too. > I will have -- and eat -- their souls. The problem with that is that the undigestible bits of "soul" just get passed right back into the ecosystem, and in a more concentrated form. Some might suggest that's already happened, and is got us here in the first place 8-} -- Matthew Fuller (MF4839) | fulle...@over-yonder.net Systems/Network Administrator | http://www.over-yonder.net/~fullermd/ On the Internet, nobody can hear you scream. _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
