"switch mode power supplies (SMPS) range in efficiencies about 75% for a "bad one" to 95% for a good one":
Yes - it is like Ideal gas (theoretical approximation) vs Real gas

wikipedia article says:
"so the converters can theoretically operate with 100% efficiency"

Of course there will be losses as you pointed out as the elements are nor ideal and have resistance.
And efficiency of 80% (using SMPS) is much better than if a linear regulator was used for the above discussed GPU:

1.2 V / 12 V = 0.1 = 10% efficiency (if linear regulator was used)


About 15 years ago I had a mainboard (unstable Jamicon used with AMD K5) with linear regulator + two small 3x2x1 cm heatsinks
to power CPU by 3.52 V from 5 V line (only (5-3.5)/5 = 0.3 = 30% lower out-voltage) and the heatsinks become very hot.

But in their description of the Buck regulator they say up to 95% efficient.

The buck regulator is the simplest step down SMPS, but is as far as I am aware, only used for battery chargers.

Read the thread by SciManStev where he in detail explains the issue:


(It's hard to read though as he (SciManStev) has the habit to write everything in one big paragraph)

.

To convert from high to low Voltage modern computer circuits use:

Switched-mode power supply
http://en.wikipedia.org/wiki/Switching_power_supply

"
A linear regulator maintains the desired output voltage by dissipating excess power <snip>

In contrast, a switched-mode power supply regulates either output voltage or current by switching ideal storage elements, like inductors and capacitors, into and out of different electrical configurations.
Ideal switching elements (e.g., transistors operated outside of their active mode) have no resistance when "closed" and carry no current when "open", and so the converters can theoretically operate with 100% efficiency (i.e., all input power is delivered to the load;
no power is wasted as dissipated heat).
"

.

just passed the 100k mark!! yipee - I wonder how long it will be to get to 200k - july the end of July?

Most electricians I've talked to won't wire up a 30A breaker to 120v as I've been told there are no 30A outlets(receptacles) and It would be unsafe as a result, possible fire danger I've been told.

120v 30a receptacles do exist. NEMA L5-30R (with NEMA L5-30P to match).

They are twist locks, and aren't often seen in a residential setting.

If you had a workshop, you might have a tool (compressor, large saw, planer) that could have an L5-30 plug.

Larger UPSes have them as the UPS cannot draw more than 80% of the line capacity.

I can see where you guys have so many power problems.
The main problems over here is back pain lugging round heavy Cast Iron 250/120 volt Mains Transformers on construction sites to comply with regulations.

Also ring mains helps in keeping cable cool as it feeds sockets from two different direction from the same fuse (meeting in the center.

UK power supply L1 N EARTH.

L1 240 volt Neutral 0-6 volts Earth.

What are Your power supply line voltages? L1 120 volt earth 0

Or L1 120 volt earth 0 L2 120 volt .

First is UK 240 volt Second using 120 volt Industrial standard.
1.0 mm2 10 amps Up to 2400 Watts Up to 1200 Watts
1.25 mm2 13 amps Up to 3120 Watts Up to 1560 Watts
1.5 mm2 15 amps Up to 3600 Watts Up to 1800 Watts
2.5 mm2 20 amps Up to 4800 Watts Up to 2400 Watts
4.0 mm2 25 amps Up to 6000 Watts Up to 3000 Watts
6.0 mm2 46 amps Up to 11000 Watts Up to 5500 Watts
10.0mm2 63 amps Up to 15000 Watts Up to 7500 Watts

Michael

I had forgotten about the ring system, seems base housing in Germany was done that way. I believe the base was started by the Brits. Couldn't do that kind of wiring here and I don't feel it is as safe as having one fuse per circuit. Lose a leg and all still works but the amps go way up.

Ring Circuit
The final ring-circuit concept has been criticized in a number of ways, and some of these disadvantages could explain the lack of widespread adoption outside the United Kingdom.

The only way to see the pros and cons of ring circuits is to compare them to the other option: radials.

[edit] Fault conditions are not apparent when in use
Ring circuits continue to operate without the user being aware of any problem if there are fault conditions or installation errors that make the circuit unsafe:[3][4]

Part of the ring missing or loose connections result in 2.5 mm2 cables running above rated current at times, resulting in reduced cable life.[5]
Radials with a loose connection will overheat severely and be an immediate fire risk.
Radials with a broken connection will not function (if L or N broken), or function with no safety earth connection (if E broken).
Accidental cross connection between two 32 A rings means that the fault current protection reaches 64 A and the required fault disconnection times are violated grossly.
Testing at installation addresses this.
Ring spur installations encourage using three connectors in one terminal, which can cause one to become loose and overheat.
The same situation occurs with both radial and ring circuits when branching off is used.
Rings encourage the installation of too many spurs on a ring, leading to a risk of overheating, especially if spur cables are too long without adequate fusing at the spur-point (i.e. a BS5733 or similar fused spur is not used) - although it should be noted that this is almost certainly a breach of the appropriate wiring code (e.g. BS7671 in the UK).

One thing you are missing is that all our plugs have fuses in. It is almost impossible to get smoke out of a power strip here. The only reliable way to smoke one is to remove the fuses & replace with something handy like a section from a 6 inch nail - good old farmers' trick :) Much over 3kW & the fuse goes in the plug. The sort of scenario that Mark had is VERY rare here.

BTW, can you get 3kW safely out of a power strip?

I know of 2kW powerstrips, But 3kW? No. But then We don't need that much I'd think, Not in a house. :D We do have GFCI outlets or this one from the wiki right Here, Which are similar to Your fused outlets.

I can see where you guys have so many power problems.
The main problems over here is back pain lugging round heavy Cast Iron 250/120 volt Mains Transformers on construction sites to comply with regulations.

Also ring mains helps in keeping cable cool as it feeds sockets from two different direction from the same fuse (meeting in the center.

UK power supply L1 N EARTH.

L1 240 volt Neutral 0-6 volts Earth.

What are Your power supply line voltages? L1 120 volt earth 0

Or L1 120 volt earth 0 L2 120 volt .

First is UK 240 volt Second using 120 volt Industrial standard.
1.0 mm2 10 amps Up to 2400 Watts Up to 1200 Watts
1.25 mm2 13 amps Up to 3120 Watts Up to 1560 Watts
1.5 mm2 15 amps Up to 3600 Watts Up to 1800 Watts
2.5 mm2 20 amps Up to 4800 Watts Up to 2400 Watts
4.0 mm2 25 amps Up to 6000 Watts Up to 3000 Watts
6.0 mm2 46 amps Up to 11000 Watts Up to 5500 Watts
10.0mm2 63 amps Up to 15000 Watts Up to 7500 Watts

Michael

I had forgotten about the ring system, seems base housing in Germany was done that way. I believe the base was started by the Brits. Couldn't do that kind of wiring here and I don't feel it is as safe as having one fuse per circuit. Lose a leg and all still works but the amps go way up.

Ring Circuit
The final ring-circuit concept has been criticized in a number of ways, and some of these disadvantages could explain the lack of widespread adoption outside the United Kingdom.

The only way to see the pros and cons of ring circuits is to compare them to the other option: radials.

[edit] Fault conditions are not apparent when in use
Ring circuits continue to operate without the user being aware of any problem if there are fault conditions or installation errors that make the circuit unsafe:[3][4]

Part of the ring missing or loose connections result in 2.5 mm2 cables running above rated current at times, resulting in reduced cable life.[5]
Radials with a loose connection will overheat severely and be an immediate fire risk.
Radials with a broken connection will not function (if L or N broken), or function with no safety earth connection (if E broken).
Accidental cross connection between two 32 A rings means that the fault current protection reaches 64 A and the required fault disconnection times are violated grossly.
Testing at installation addresses this.
Ring spur installations encourage using three connectors in one terminal, which can cause one to become loose and overheat.
The same situation occurs with both radial and ring circuits when branching off is used.
Rings encourage the installation of too many spurs on a ring, leading to a risk of overheating, especially if spur cables are too long without adequate fusing at the spur-point (i.e. a BS5733 or similar fused spur is not used) - although it should be noted that this is almost certainly a breach of the appropriate wiring code (e.g. BS7671 in the UK).

I will therefore of course uninstall and then reinstall the OS on my computers, as well as the Boinc client.

I agree with your logic completely! I just finished my 17th reinstall of the OS today, and I think my uploads will resume shortly! Hang tight, will post my success soon!

I just replaced the fuses in my electric panel with new ones and it did not help. Uploads still don't work. Got any other ideas :)

Thank you Richard for your rational discussion of the matter.
Some of us apply more emotion than logic to the situation, and then things degrade to personal attacks when others do not agree with our thoughts or opinions.
Which does little to advance any resolution to the subject at hand.

Excellent link, Odan. Loved the read and I think it aptly applies here.

Ok, who am I talking to? I was teasing Dan about the screenshot he posted. Took me a minute to figure out he was from GB and his days and months are backward. It's almost as bad as all those useless Us you guys stick into every other word! :-)

Everybody knows you should be using the ISO 8601 date format YYYY-MM-DD :p
http://en.wikipedia.org/wiki/ISO_8601