No subject

is much cheaper than buying new storage. Transcoding for the
time-shifter that has enough capacity without transcoding makes no
sense whatsoever, obviously since that person is transcoding for no
reason really.  So the last interesting case is the person who doesn't
have enough working space to time-shift all that they would like
without transcoding.

This person has 2 options:  upgrade to a larger drive, or turn on
transcoding.  Since we aren't looking at long term storage of these
items, how much TV would you have to transcode to end up spending more
on that than buying a larger drive (costing themselves money)?  How
big of a drive is somewhat subjective and depends on how much TV the
user wants to time-shift, so for now we'll assume that a 500GB drive
would be sufficient. Assuming the new replacement drive's power usage
is the same as the current drive (which may or may not be the case),
and the previously discussed numbers we can arrive at the following:

New 500GB HD                   = $60
Cost per hour of transcoding = 50W * $0.09 = $0.0045/hr
Hours of transcoding needed to equal cost of a new drive = $60 /
$0.0045/hr = 13,333 hours (~555 days)

Given the assumptions either explicitly or implicitly made here
(backend running 24/7, little or no difference in drive power usage,
etc.) transcoding still seems to be viable for this person.  These
numbers may be a bit skewed since my electricity cost is relatively
low, and the Q6600 is quite efficient at encoding but 13,333 hours is
a LOT of TV watching/recording to do before the break even point.

Of course this analysis is only taking into account the cost alone,
and doesn't factor in some of the other good points made relating to
drive failures etc.

--Dave