Jeff Liebermann wrote:
On Mon, 02 Nov 2009 20:18:50 -0700, D Yuniskis
wrote:

Spin the disk down when it isn;t being used!

Sure, but I don't have any control over the DirecTV firmware. What I

Of course! My point was that *they* could still make significant
savings in their dessign.

have is what I have to live with. My guess(tm) is that they spin the
disk continuously to improve the operating life of the hard disk
drive. I have servers that run 24x7x365 that never seem to eat a disk

Spin the drives down and then try spinning them back up! :
(i.e., the stress seems to be on the spin-up)

I think modern drives have really long MTBFs. What kills
disks is the same thing that kills most electronic things: heat.

drive. I have one in the office that's been running continuously
since about 1995. However, the same drives, will die after 3-5 years
with start-stop operation.

I haven't lost a disk in 30 years (touch wood). The drives in my
primary machine have date stamps of 2002. They see a fair bit
of power cycling (since the machine doesn't have a reset button,
the only way to truly reset it is to cycle power and wait for
all the drives to spin up again).

Done properly, even that 6W figure could turn into 1/2W as
the entire device could sleep when not in use -- and just
wake-up when the next "alarm time" is scheduled *or* when
IR is sensed from the remote.

Well, it's not quite so simple. The box downloads firmware updates
and program listings erratically. It also calls home on the phone
line in the middle of the night for pay per view and quality control.

These aren't random events. There is software inside the
box *deciding* when to do these things. So, it could
go to sleep and still have told something to wake it up
at its next scheduled activity.

I can also make record schedule entries via the internet. If the LNB
is powered down, it takes about a minute for things to settle down and
stabilize again. Power consumption can probably be drastically
reduced using some manner of standby mode, but my box is VERY busy,
which means the algorithm may be rather complex and the savings rather

Modern processors have very complex power management features
*in* the processor (SMI). If they aren't being exploited,
it is because the box's manufacturer was just lazy (and had
no incentive to do so!)

limited. If it costs me about $3/month to avoid complications and
extend the life of the hard disk, I would probably pay the price.

I've been moving all of my "software" (movies, music) onto
large disks (several TB) so that I can serve this from a
single machine. I let the drives power down when not in use.
My biggest problem is the network switch that I rely on
for distribution as it can't be powered down.