22 Sep
2006
22 Sep
'06
04:19
On Thursday 21 September 2006 08:50, Paul Abrahams wrote: > Fun, fast, and reliable, I agree. But cheap? 14 systems at 300 watts per > system (typical power supply rating) comes to 4200 watts of constant draw. > That's a pretty hefty electric bill. Yeah, but that's not how the power stacks up.... 1) I have no cathode ray tubes.... last one went to recycling center months ago. Those things are the real power hogs. 2) I have no machines with a power supply rated in excess of 250watts. Most of them use a power supply rated at less than 200watts, and several are rated at less than 150watts. 3)Modern power supplies aren't like a lightbulb... always drawing (delivering) their rated power... far from it. They are switching supplies and run at a fraction of their rating... unless of course the user adds stuff that draws more power. Switching means that the machine's power supply delivers more power as its needed (more current at the same regulated voltage) using a technology called pulse width modulation. Circuitry that senses a voltage drop increases the width of the transformer pulses and whalla... same voltage out at increased current... and increased power dissipation. All this boils down to the fact that a headless computer with no hardware except HD, MB, and Eth, (no dvd, cd, floppy, extra drives, sound cards, midi ports, display cards, etc) will run at a surprisingly small percentage of the system's power supply rating... maybe 1/3 or less. Most of my machines are drawing less power than a 60watt lightbulb. By the way, most rack mounted slim pcs are similar. My are in cases, however. 4) I have never measured this.... strange for a guy like me... so, tomorrow, I will take a reading with everyting down... and another reading with everyting up... and I'll let you know... but I can tell you this... the only time the dial spins fast on my meter is when the AirC is on... ;-) I'll bet most folks burn more power running their lights than I do running my network... we'll see. 5) The "cool" thing "literally" about Linux is that most of the time the processor is idle... run top sometime and check it out. Processors get hot (consume more power) while they are cycling... when idle they run cooler and consume less power... so most of the time the MB is drawing dissipating minimal power. Of course this isn't true when everything is clicking. :) 6) I MAY HAVE MISLED YOUS GUYS.... when I said they never go down I didn't mean they run 24x7. (for instance the whole shooting match is off-line during storms 'n such) What I meant was that we are not *down* do to hardware failure.... in other words, when I lose a drive I don't lose data and the family is not without the network while that one machine is being repaired. In fact, last week I lost two drives (on the same day, both WDs 8 years old) and the family did not lose the computer network, data, or functionality. Redundancy, backup, and alternate paths are key on modern systems I think. Bill is still stuck in the windoze mode of thinking that everyone is surfing gleefully through MSN.com and playing 3D games all day... for crying out loud most of my machines have no monitor and four of them have no wires at all except for the power cord (they are the wifi guys, the vulnerable part of the experiment). -- Kind regards, M Harris <><