[mythtv-users] Power bill vs SchedulesDirect bill

Brian Wood beww at beww.org
Wed Sep 19 02:59:48 UTC 2007

Yan Seiner wrote:
> Robin Hill wrote:
>> You will, of course, need to make sure the power supply is big enough
>> for your needs.  Remember to check on each power rail, not the total -
>> it's no good needing 100W at 5V when it only supplies 60.
> One thing to keep in mind:
> Hard drives can take a lot more power to spin up than to run.
> So if your box is loaded up with 4-6 drives, you probably need a honking 
> big PS even if your continuous power needs are pretty low.
> Some SCSI controllers have a 'staggered spinup' feature where each drive 
> is brought up by itself, followed by the next drive, and so on.  (A 
> necessity - my dual channel SCSI card can control 30 drives so spinning 
> up that many drives at once would probably dim the lights in the house.) 
>   With new mobos having 4 - 6 SATA connectors, it would be nice if the 
> drives could be told to spin up sequentially rather than all at once.

You can get little devices that go in line with the disk drive power to
delay the spinup after power is applied. If oyu have more than 2 drives
you can stagger the delays.

Weakknees uses these in their "add-a-drive" kits for TiVos, as they
figured out that the TiVo PSU can't support the simultaneous spinup of
multiple drives.


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