Mark Morgan Lloyd wrote:
Jordan Bettis wrote:
Like Chris said, new machines generally draw a lot more power overall.
My Ultra 5 that I use as my desktop can draw 200W max, and probably
doesn't really draw much over 100W total. Compare that to a typical
modern PC desktop that has a 400W supply in it and probably draws well
over 200W, mostly to power a GPU so it can display silly bouncing
icons and semi-transparent window edges.
There are two separate things to take into account here. The first is
the quiescent consumption, I admit to not having values from a number of
systems so for the sake of argument I'll agree that this is generally
increasing. However I'd suggest that if a computer is sitting there
doing noting you'd be better looking for ways to power it off or use a
shared computing resource- Sunray or whatever.
When they say sitting there doing nothing what I think they mean is
sitting there at 2% load compared to working at 80% load. For
example, an old SS5 running as a firewall. Replacing it with a P4 would
gain you nothing but an increased power bill.
The second thing- where I do have numbers to back up my argument- is how
much energy is consumed to perform a unit of work. My figures, by and
large, show that while running a torture test a range of computers
consume between 60 and 550W, with no overwhelming correlation with their
age. On the other hand the time to complete a unit of work has dropped
dramatically over the last 20 years, which leads me to suggest that by
and large the energy consumed per unit of work has also dropped
significantly.
Looking at two extreme cases:
SPARCstation 20, 2 jobs, 130W (175VA)8m12.582s1,068
Compaq AP550 1GHz, 768Mb, 8 jobs, 135W (180VA)0m42.730 96
That last column is W-min to complete a given workload, selecting the
best (fastest) figures by splitting it into a number of jobs.
So assuming that the quiescent consumption is equal you're /far/ better
off with a newer system since even if it consumes substantially more
power while working hard it does so for far less time.
Again, that's fine if you have more work for it to do. I would gain no
benefit by replacing my SS5 as it works just as well for the task in
hand as it did when it was new. A new machine would just be spinning
it's wheels 98% of the time, using more electricity, which in turn
generates heat, which makes my A/C work harder, which uses more
electricity...
Analogy: An old grandmother drives an old sub-compact. Sure she could
get more groceries in an SUV, but she doesn't want/need more room for
groceries. So why pay more for something she doesn't need?
Regards,
Ozz.
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