On Thursday 21 April 2005 2:55 pm, Paul Tansom wrote:
A quick look into power supplies that have intelligent fans, for example, found one that looked good (listed as fanless which is incorrect, but it does spin down when not needed). That costs around £90, so how many years would it take to repay the cost in terms of power savings!
Also just because the Fan is temprature controlled doesn't mean the power supply is that much more efficient (there are also genuine Fanless models, but they radiate a similar amount of heat just using convection) Anyway you are still needing x amount of watts to run the system even if you had a 100% efficient PSU.
In any case if you move from say a Prescott P4 to a P4M then the power savings are far greater (and you could move to the power brick/DC-DC converter style of PSU's which don't always need active cooling)
Also you have to consider your case design when looking at fanless PSU's (or ones that turn the fan down to idle or stop) as some machines rely on the PSU to pull air through the rest of the case and you could get thermal problems in other areas of the machine without that flow.
On another side, when you look at recycling old PC kit which is arguably less energy efficient, is it better to scrap it and use something that is cheaper to run. Then again the current range of CPUs are real power hogs (compare around 8W for a 486 to 120W for a top end P4).
Depends on how you calculate it Power Consumed vs Work Done - New kit will probably win Power Consumed vs Time Switched On - Old Kit will probably win
The exception to this is of course things like functional power management and LCD screens.
Being environmentally friendly is hard work and a confusing area, however good that may be - and necessary in the long run.
Tell me about it, I feel guilty about leaving this AMD 64 monster running 24/7, but I need to access it remotely (as do others). I wish it could clock itself down to say 300MHz when it is idle (and perhaps then shut down or idle the CPU and PSU fans) but at least under Linux there seems to be no way of achieving that.
A P4M machine on the other hand could easily run fanless 90% of the time.
I guess it's market forces, people buy computers based on bogus performance figures and hardly anyone seems to consider running and environmental costs. A P4M system would (at the moment) probably cost 30-40% more to build and you could only put a 2GHz sticker on the box. People would see that and walk away to buy the cheaper P4 3GHz monster, regardless of their actual needs or actual performance (clock for clock the P4M's walk all over the Prescott P4's)