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) 8m12.582s 1,068 > > 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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