I did a calculation maybe a year ago;

A PC consuming 200watts, or 0.2Kw, costs 50p per day, or £0.50.

£0.50 x 8 PCs = £4.00 per day

x 365 = £1,460.00 per year to run 8 PCs 24/7 (approximately)

Does anyone else have estimates of their running costs?

---

flaming balloons

2 machines using approx 300 w (combined) = 2628 Kw/yr @ $0.07/Kw = $183.96 (CDN)

Or, very roughly, £95.00/yr.

10 Machines = ~ 1 kWr * .06 average = .06 cents an hour US = $1.44 a day = $526.6 a year.

---

Fear will keep the local systems in line. Fear of this battle station. - Grand Moff Tarkin

Note: all machines currently running Cosmology@home (taking a SETI break).
1.926 (KW) * 720 (Hrs/Mo) * 0.06 ($/KW/HR) = $83.20 /Mo or $998.40 /Year.

---

Boinc Button Abuser In Training >My Shrubbers<

Last month I know that running 3 PCs (among other things) cost Me $135.56, Next month I'll know about what roughly 1 PC will cost as I'm now running only 2 QX6700 PCs, The PC that is offline is a dual core PC, But It will tell Me something, I'd tell You what each PC uses per day in Kilowatts, But I have a limited/fixed budget and as such I don't have a kilowatt device to find that out with since I have other objectives that take a higher priority.

Got a stopwatch? That'll do it.

---

I know that running my AMD 3800+ X2 machine costs me roughly $15 per month at PG&E's outrageous prices for electricity because I've empirically tested this.

---

My q6600@3ghz/4hdd/8800gts draws ~230W when just crunching SETI.

So 230w x 720h = 165600w, 165.6kW/h

Around AU14c/kWh I think here, so that makes $23.20 per month crunching cost for around 2500-3000 credits/day. Which is probably quite efficient, and would be more so if I had a dedicated cruncher sans 3 of the hdds and the 8800.

---

Crunching SETI@Home as a member of the Whirlpool BOINC Teams

My three systems together average about 240 watts crunching SETI. At current electric rates here, that's about 84.3 US cents per day.

Where I live, the climatological records since 1948 show average daily temperature above 70 fahrenheit for only about 12 days in mid July. The rest of the year, I need a small amount of extra heat and am happy to get the SETI crunching as a free side benefit.

12 x 0.843 = $10.12 US/year.

                                                                 Joe

Rather than reading the power supply ratings and adding the values, what is a good way to measure the power being used by each of our PC's?

Rather than reading the power supply ratings and adding the values, what is a good way to measure the power being used by each of our PC's?

Get yourself one of these

-Dave

---

Rather than reading the power supply ratings and adding the values, what is a good way to measure the power being used by each of our PC's?

Get yourself one of these

-Dave

Almost sounds good, but the negative reviews on NewEgg are rather scary. I'll look for alternatives at Fry's next time I'm there.

Rather than reading the power supply ratings and adding the values, what is a good way to measure the power being used by each of our PC's?

Adding up the power supply ratings can be woefully inaccurate. Just good engineering practice calls for the average load to be half the power supply rating, or a little less. You don't want the supply running flat out.

Others have suggested a Kill-a-watt or equivalent meter, and those are pretty wonderful, and easy to use.

There is another kilowatt-hour meter, and we most all have one provided "free" by the utility. With that meter and a stopwatch, you can tell exactly what your house is drawing -- and with fairly good precision.

This also matches EXACTLY how the utility measures, and it kills all the silly questions about VA vs. Watts, power factors and everything else. For most of us, a good power factor is not an advantage. The utility would disagree.

If you want to stopwatch your meter, instructions are here.

---

Rather than reading the power supply ratings and adding the values, what is a good way to measure the power being used by each of our PC's?

As Ned pointed out, adding up the ratings of a power supply would give you the *maximum* draw, but the actual usage would be less. In my experience, when sizing a power supply you should probably strive for about 2/3 of the maximum power. For instance if your system draws 300 watts with everything working (reading/writing to all hd's, all fans running full speed, etc.) then a 450 watt supply would be adequate and give the best performance. At higher or lower loading the power supply efficiency would decrease, regulation would suffer, and ripple would increase. Also at higher loading you would run the risk of overloading the supply when the hd's are spinning up after a power down, etc.
So the ratings on a power supply are not a good indicator of the actual power consumption. There are many different wattmeters on the market, the "kill-a-watt" mentioned seems to be highly rated by other users (I've never used it myself). If you want an accurate measurement of power used, by far the best way is by using one of these. However as Ned pointed out, there are other ways of doing this.

---

Jim

Some people plan their life out and look back at the wealth they've had.
Others live life day by day and look back at the wealth of experiences and enjoyment they've had.

If you want to stopwatch your meter, instructions are here.

I am constantly in awe of human diversity; in this case, the professional treatment of using the external power meter, which in my opinion Faraday could have invented and not changed since. Talk about a niche-market for a youtube vid!

Rather than reading the power supply ratings and adding the values, what is a good way to measure the power being used by each of our PC's?

As Ned pointed out, adding up the ratings of a power supply would give you the *maximum* draw, but the actual usage would be less. In my experience, when sizing a power supply you should probably strive for about 2/3 of the maximum power. For instance if your system draws 300 watts with everything working (reading/writing to all hd's, all fans running full speed, etc.) then a 450 watt supply would be adequate and give the best performance. At higher or lower loading the power supply efficiency would decrease, regulation would suffer, and ripple would increase. Also at higher loading you would run the risk of overloading the supply when the hd's are spinning up after a power down, etc.
So the ratings on a power supply are not a good indicator of the actual power consumption. There are many different wattmeters on the market, the "kill-a-watt" mentioned seems to be highly rated by other users (I've never used it myself). If you want an accurate measurement of power used, by far the best way is by using one of these. However as Ned pointed out, there are other ways of doing this.

Regarding Kill-a-watt, check the negative reviews on EggHead (I always ignore the positive ones first, which are more likely to be written by someone with an iron in the fire - on average). They indicate that the instrument is pretty fragile and fails readily, although it "initially" works as advertised.

Rather than reading the power supply ratings and adding the values, what is a good way to measure the power being used by each of our PC's?

As Ned pointed out, adding up the ratings of a power supply would give you the *maximum* draw, but the actual usage would be less. In my experience, when sizing a power supply you should probably strive for about 2/3 of the maximum power. For instance if your system draws 300 watts with everything working (reading/writing to all hd's, all fans running full speed, etc.) then a 450 watt supply would be adequate and give the best performance. At higher or lower loading the power supply efficiency would decrease, regulation would suffer, and ripple would increase. Also at higher loading you would run the risk of overloading the supply when the hd's are spinning up after a power down, etc.
So the ratings on a power supply are not a good indicator of the actual power consumption. There are many different wattmeters on the market, the "kill-a-watt" mentioned seems to be highly rated by other users (I've never used it myself). If you want an accurate measurement of power used, by far the best way is by using one of these. However as Ned pointed out, there are other ways of doing this.

Regarding Kill-a-watt, check the negative reviews on EggHead (I always ignore the positive ones first, which are more likely to be written by someone with an iron in the fire - on average). They indicate that the instrument is pretty fragile and fails readily, although it "initially" works as advertised.

Yeah, but that's 2 out of 73 reviews, that kind of failure rate could be seen on almost anything. I've seen similar reviews for other stuff (motherboards, hard drives, etc.) that I've bought from NewEgg. I usually look at the negatives first and if there are only a small percentage, I tend to discount them. Just like you say about the positive ones, the negatives can also be written by someone who has a grudge.

-Dave

---

Regarding Kill-a-watt, check the negative reviews on EggHead (I always ignore the positive ones first, which are more likely to be written by someone with an iron in the fire - on average). They indicate that the instrument is pretty fragile and fails readily, although it "initially" works as advertised.

Mine is several years old, and while I haven't actually dropped it, it has proven to be pretty durable.

More to the point, I've compared my results on the Kill-a-watt to my results stopwatching the meter. It is fairly accurate.

The big surprise is that you'd think a heater marked "1500 watts" would be a pure resistive 1500 watts, and it's not. It's not even constant, it changes with temperature.

---

Regarding Kill-a-watt, check the negative reviews on EggHead (I always ignore the positive ones first, which are more likely to be written by someone with an iron in the fire - on average). They indicate that the instrument is pretty fragile and fails readily, although it "initially" works as advertised.

I'm a Kill-a-watt fan. I do wish it had a reset button (you have to disconnect it from power to restart the accumulation).

The most credible claims of trouble I've heard were from folks who put it downstream of a UPS that made a bad stepped-approximation sinuosoid waveform. Claims are that when the UPS went into actual backup mode the Kill-a-watt was harmed.

As the doctor says when you say "Doc, it hurts when I do @#$%", "well, then don't do @#$%"

Compared to the LaCrosse Cost Control which I also own, the Kill-a-Watt seems a better-made product physically. As to functional differences, the Kill-a-Watt displays Power Factor and VA, which the Cost Control does not. The Cost Control has a reset button, and allows you to enter your power rate so it can compute cost, which the base Kill-a-Watt model does not.

The power factor for my PC with a standard supply was impressively far from 1--about 0.5, so far as I recall. My PC with a Seatronic supply advertised as having active power factor correction scored something like .99. A light bulb was also right about 1.00, as it should be.

Aside from your power company wishing you would be kind to their system stability, you should know the actual VA of the load to assure you have sized a UPS properly.

Folks I think technically competent in other forums have posted conclusions from comparison of the readings from a Kill-a-Watt with professional test equipment. The conclusion was that within its operating range it is a surprisingly accurate piece of equipment.

I think folks here interested in the power consumption of their PC, its change when running BOINC, and the like, would be very well advised to get one.

---

The power factor for my PC with a standard supply was impressively far from 1--about 0.5, so far as I recall. My PC with a Seatronic supply advertised as having active power factor correction scored something like .99. A light bulb was also right about 1.00, as it should be.

If the power factor is 1, then VA and Watts are the same value.

As end-users, you use VA to size backup generators and UPSes, but other than that it isn't that important.

As a ratepayer, I pay for watts, not volt-amps. Given that, I really don't care what the power factor might be. If I could run on a 400va power supply with a power factor of 0, I'd be exceedingly happy.

---

I'm also a fan, have two, one with UK connectors From Maplins, and one with European connectors, shop bought in Milan. Both are accurate within a few percent of professional devices. And have survived for several years intact, even though they live in toolbox and have had several helicopter flights.