Jeff.Miller@samba.acs.unc.edu (BBS Account) (09/17/90)
Someone asked if PC's really do consume 200 watts: It very much depends on the machine and configuration. When estimating power consumption it is important to note that most switching power supplies are less than %70 efficient. Certain UPS schemes are also very inefficient, that must be considered also if you are using these. I would say the average clone draws between 100 and 250 watts. The average monitor another 40. Power=heat, if the air coming out of your pc carries little heat than your system draws little power, if you notice your PC heats your room it might be drawing quite a bit. Hard to guess, as a gentle breeze that is quite warm might carry less heat than a strong blast which feels cooler. Measuring power consumption for computers is complicated by the fact that the curent is drawn as a narrow high-current pulse that tricks most AC voltmeters. Equipment is generally becoming more efficient per unit processing power. As mentioned, power draw is usually pretty constant regardless of sytem load. It might be interesting to point out I had a sytem which actually drew less power as the HD heads zipped around. Running memory intesive programs had little impact on power consumption but programs which used the math coprocessor did use more power. I would be interested in other studies and personal experiences in the area of reliabilty verses power cycling. I for one am a total power-on-demand convert, it has saved me hundreds over the last several years. I have never had a peice of equipment fail. -Jeffrey --
domo@tsa.co.uk (Dominic Dunlop) (09/18/90)
In article <1084@beguine.UUCP> Jeff.Miller@samba.acs.unc.edu (BBS Account) writes: > Someone asked if PC's really do consume 200 watts: Seems like the right number -- plus or minus a good fifty percent. > > [Useful hints omited] > > Measuring power consumption > for computers is complicated by the fact that the curent is drawn as a > narrow high-current pulse that tricks most AC voltmeters. This is true. But, luckily for the power utilities, it does not fool the meter which measures your house power consumption, and from which your electric bill is generated. So, if you're in a position where you can kill most or all of the other electrical appliances connected to the meter, you can laboriously count how many times the disk rotates as you turn parts of your PC on and off, and so establish their power consumption with reasonable accuracy. Myself, I turn off my two-page monitor at night, and I certainly turn off my laser printer. Although laser printers have no objection to being powered continuously, they have a steady state power consumption of several hundred watts (and even more when printing). -- Dominic Dunlop
zeeff@b-tech.ann-arbor.mi.us (Jon Zeeff) (10/02/90)
>Someone asked if PC's really do consume 200 watts: > >It very much depends on the machine and configuration. When >estimating power consumption it is important to note that most > >I would say the average clone draws between 100 and 250 watts. The Lots of speculation and estimates. Actual measurments indicate that my mosts slots filled '286 clone uses 85 watts. The mono monitor uses < 20. >than a strong blast which feels cooler. Measuring power consumption >for computers is complicated by the fact that the curent is drawn as a >narrow high-current pulse that tricks most AC voltmeters. I use the same kind of meter the power company does. -- Jon Zeeff (NIC handle JZ) zeeff@b-tech.ann-arbor.mi.us
peter@ficc.ferranti.com (Peter da Silva) (10/03/90)
> >than a strong blast which feels cooler. Measuring power consumption > >for computers is complicated by the fact that the curent is drawn as a > >narrow high-current pulse that tricks most AC voltmeters. > I use the same kind of meter the power company does. There is a whole industry that operates by "optimising" load for office buildings, taking advantage of the characteristics of the kind of meter the power company uses. -- Peter da Silva. `-_-' +1 713 274 5180. 'U` peter@ferranti.com