John Levine <johnl@taugh.com> schrieb:
> According to Lawrence D'Oliveiro <ldo@nz.invalid>:
>>On Wed, 24 Apr 2024 23:10:47 -0600, John Savard wrote:
>>
>>> One of the things that those supercomputers that _do_ include GPUs are
>>> praised for is being energy-efficient.
>>
>>That I never heard before. I heard it in relation to ARM CPUs, yes, GPUs,
>>no.
>
> NVIDIA says their new Blackwell GPU takes 2000 watts, and is between
> 7x and 25x more power efficient than the current H100, but that's
> still a heck of a lot of power. Data centers have had to come up with
> higher capacity power and cooling when each rack can use 40 to 50KW.

GPUs are very energy efficient per theoretical peak performance of
calculations per second. Said peak performance is extremely high,
hence the huge power requirements...

But programming for GPUs is _much_ harder than programming for
vector computers used to be. Getting to 10% of theoretical peak
performance is quite impressive. Getting above 50% requires
the right problem, good knowledge of the GPU internals (which NVIDIA
does not tend to share - don't they want to have people have good
performance on their cards? and lots of thought and _very_ clever
algorithms.

> I mean, my entire house is wired for 24KW and usually runs at more
> like 4KW including a heat pump that heats the house.

Good thing you're not living in Germany, your electricity bill
would be enormous...

John Savard <quadibloc@servername.invalid> schrieb:
> On Thu, 25 Apr 2024 05:39:55 -0000 (UTC), Lawrence D'Oliveiro
><ldo@nz.invalid> wrote:
>
>>On Wed, 24 Apr 2024 23:10:47 -0600, John Savard wrote:
>>
>>> One of the things that those supercomputers that _do_ include GPUs are
>>> praised for is being energy-efficient.
>>
>>That I never heard before. I heard it in relation to ARM CPUs, yes, GPUs,
>>no.
>
> Here's one example of an item about this:
>
> https://www.infoworld.com/article/2627720/gpus-boost-energy-efficiency-in-supercomputers.html

Compared the late 1950s, was the total energy consumption by
computers higher or lower than today? :-)

On 4/25/2024 12:45 PM, Michael S wrote:
> On Thu, 25 Apr 2024 17:34:32 +0000
> mitchalsup@aol.com (MitchAlsup1) wrote:
>
>> Michael S wrote:
>>
>>> On Thu, 25 Apr 2024 15:52:36 +0000
>>> mitchalsup@aol.com (MitchAlsup1) wrote:
>>>>
>>>> Seymore only did fast and simple, starting before the CDC
>>>> 6600.....
>>
>>> Do you attribute not exactly simple 6600 Scoreboard to Thornton?
>>
>> If you measure simplicity by gate count--the scoreboard was
>> considerably simpler than the reservation station design of Tomasulo.
>
> Both were far from simple by day's standards.
>
> BTW, was not low gate count of Scoreboard mostly due to creative usage
> of what was later named wired logic connections, i.e. something that
> stopped working in high-speed VLSI around 1985-1990 ?
>

Still kinda funny in a way that one can't really extrapolate backwards...

Say, seemingly no one built an 8/16 bit mainframe, or say using 24-bit
floats (Say: S.E7.F16) rather than bigger formats, ...

Like, seemingly, the smallest point of computers was seemingly things
like the 6502 and similar...

Also funny to think in a way that Binary16 is the newer format, because
seemingly previously no one bothered with floating-point numbers much
smaller than 32-bits (despite the usual expected trend of things getting
bigger over time).

....

According to Thomas Koenig <tkoenig@netcologne.de>:
>> https://www.infoworld.com/article/2627720/gpus-boost-energy-efficiency-in-supercomputers.html
>
>Compared the late 1950s, was the total energy consumption by
>computers higher or lower than today? :-)

Well, compared to what?

In 1960 the total power generated in the US was about 750 TWh. In
recent years it's over 4000 TWh.

I see global data center power use in recent years of about 250 TWh,
and about the same again in data transmission, but I don't know how
much of that to attribute to the US.

--
Regards,
John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly

On Thu, 25 Apr 2024 15:52:36 +0000, MitchAlsup1 wrote:

> [Seymour] only did fast and simple, starting before the CDC 6600.....

And he didn’t seem to have much truck with “memory management” and
“operating systems”, did he? He probably saw them as just getting in the
way of sheer speed.

And he didn’t care for some of the niceties of floating-point arithmetic
either, for the same reason.

Lawrence D'Oliveiro wrote:

> On Thu, 25 Apr 2024 15:52:36 +0000, MitchAlsup1 wrote:

>> [Seymour] only did fast and simple, starting before the CDC 6600.....

> And he didn’t seem to have much truck with “memory management” and
> “operating systems”, did he? He probably saw them as just getting in the
> way of sheer speed.

Base and bounds was good enough for numerical programs.

On the other hands, NOS did things no other OS did.....

> And he didn’t care for some of the niceties of floating-point arithmetic
> either, for the same reason.

Heck, FP arithmetic is only approximate anyway--it is just more
approximate on my machines.....

On Thu, 25 Apr 2024 22:29:30 +0000, MitchAlsup1 wrote:

> On the other hands, NOS did things no other OS did.....

Like what? I thought the original Cray OS was just a batch OS.

Then they added this Unix-like “UNICOS” thing, but that seemed to me like
an interactive front-end to the batch OS.

On Thu, 25 Apr 2024 14:57:53 +0300, Michael S wrote:

> Back when Fugaku was new, it was highly praised for being GPU-less
> design that matches and slightly exceeds an efficiency of GPU-based (and
> other vector accelerator based) supercomputers. But that was possible
> only because NVidea had unusually long pause between successive
> generations of Tesla and at the same moment AMD and Intel GPGPUs were
> not yet considered fit for serious supercomputing.
>
> That was in November 2019. Never before or since.

Fugaku is still at number 4 on the Top500, though--even after all these
years. And don’t forget the Chinese systems, using their home-grown CPUs
without access to Nvidia GPUs. There’s one at number 11.

Should we be looking at the Green500 list instead?

Lawrence D'Oliveiro wrote:

> On Thu, 25 Apr 2024 22:29:30 +0000, MitchAlsup1 wrote:

>> On the other hands, NOS did things no other OS did.....

> Like what? I thought the original Cray OS was just a batch OS.

One afternoon in 1978, I was in the typing room at NCR Cambridge typing
in my 8085 ASM code; there were another 6 of us in there. NCR rented
time on a CDC 7600 in San Diego.

Suddenly there was a long pause where the silent 700's made no noise;
and after 20 or so seconds, the pause ended and we proceeded along
with our work. I discovered later that the San Diego machine had taken
a hard crash and all our jobs had been picked up by the PPs and shipped
en massé to a CDC 7600 in Chicago (including the files those jobs were
using.)

> Then they added this Unix-like “UNICOS” thing, but that seemed to me like
> an interactive front-end to the batch OS.

It was, and it was written in interpreted BASIC.

On Fri, 26 Apr 2024 00:33:50 -0000 (UTC)
Lawrence D'Oliveiro <ldo@nz.invalid> wrote:

> On Thu, 25 Apr 2024 14:57:53 +0300, Michael S wrote:
>
> > Back when Fugaku was new, it was highly praised for being GPU-less
> > design that matches and slightly exceeds an efficiency of GPU-based
> > (and other vector accelerator based) supercomputers. But that was
> > possible only because NVidea had unusually long pause between
> > successive generations of Tesla and at the same moment AMD and
> > Intel GPGPUs were not yet considered fit for serious supercomputing.
> >
> > That was in November 2019. Never before or since.
>
> Fugaku is still at number 4 on the Top500, though--even after all
> these years. And don’t forget the Chinese systems, using their
> home-grown CPUs without access to Nvidia GPUs. There’s one at number
> 11.
>

From the very little info I found about it, Sunway TaihuLight
processors are likely more similar to Intel KNC (a.k.a. Xeon Phi
co-processor) than to Fujitsu A64FX. I.e. simple in-order cores, likely
2-way superscalar, with single-issue wide VPUs. In other words,
decisively non-general-purpose.

> Should we be looking at the Green500 list instead?

Of course we should be looking at Green500 when discussing power
efficiency.

On Thu, 25 Apr 2024 14:27:46 +0300, Michael S wrote:

> On Wed, 24 Apr 2024 22:29:36 -0000 (UTC)
> Lawrence D'Oliveiro <ldo@nz.invalid> wrote:
>
>> On Wed, 24 Apr 2024 09:18:56 GMT, Anton Ertl wrote:
>>
>> > But the Cray-1 is not an improvement on the Model 195.
>>
>> The Cray-1 was widely regarded as the fastest computer in the world,
>> when it came out. Cruising speed of something over 80 megaflops,
>> hitting bursts of about 120.
>>
>> IBM did try to compete in the “supercomputer” field for a while longer,
>> but I think by about ten years later, it had given up.
>
> BTW, in the latest Top500 list you ca see IBM at #7 spot.

Those are POWER machines, an entirely different architecture from the
System 360-and-successors line (which I think was meant by “Model 195”).
And one which still has a bit of oomph left in it, obviously.

MitchAlsup1 <mitchalsup@aol.com> wrote:
> Let us face facts:: en the large; vector machines are DMA devices
> that happen to mangle the data on thee way through.
>
> John Savard wrote:
>
>> And if memory bandwidth issues make Cray-style vector machines
>> impractical, then wouldn't it be even worse for GPUs?
>
> a) It is not pure BW but BW at a latency less than K. CRAY-1 was
> about 16-cycles (DRAM)

DRAM for CRAY-1 doesn't sound right. Intel made 1024-bit DRAM in 1970,
but it was pretty flaky and not very fast. I think the CRAY-1 used
Fairchild 10K ECL 10ns SRAM.

Andrew,

BGB <cr88192@gmail.com> schrieb:

> Say, seemingly no one built an 8/16 bit mainframe,

The IBM 360/30 and 360/40 actually had a 8 and 16-bit
microarchitecture, respectively. Of course, they hid it cleverly
behind the user-visible architecture which was 32 bits.

But then, the Nova was a 4-bit system cleverly disguising itself
as a 16-bit system, and the Z80 had a 4-bit ALU, as well.

> or say using 24-bit
> floats (Say: S.E7.F16) rather than bigger formats, ...

Konrad Zuse used 22-bit floats.

> Like, seemingly, the smallest point of computers was seemingly things
> like the 6502 and similar...

That was probably the PDP 8/S, which had (if Wikipedia is to be
believed) around 519 logic gates. The 6502 had more.

John Levine <johnl@taugh.com> schrieb:
> According to Thomas Koenig <tkoenig@netcologne.de>:
>>> https://www.infoworld.com/article/2627720/gpus-boost-energy-efficiency-in-supercomputers.html
>>
>>Compared the late 1950s, was the total energy consumption by
>>computers higher or lower than today? :-)
>
> Well, compared to what?

Absolute figures, or relative :-)

>
> In 1960 the total power generated in the US was about 750 TWh. In
> recent years it's over 4000 TWh.

My point was: Computers have become vastly more energy-efficient
and powerful. I think one of the "What If 2" chapters is about
building an Iphone out of vaccum tubes, which would end badly.

This has led _much_ more widespread adoption of computers plus
derivatives such as smartphones or tablets, which means that
their overall energy consumption has increased by many orders
of magnitude over the 1950s, when just a few vaccum-tube based
computers were in operation.

If people make the claim that GPUs are more power-efficient than CPUs,
yes, they are for equal performance (if they can be programmed
efficiently enough for the application at hand). In practice, this
will not be used for energy savings, but for doing more calculations.

Same thing happend with steam engines - Watt's engines were a huge
improvement in fuel efficiency over the previous Newcomen models,
which led to much more steam engines being built.

aph@littlepinkcloud.invalid wrote:

> MitchAlsup1 <mitchalsup@aol.com> wrote:
>> Let us face facts:: en the large; vector machines are DMA devices
>> that happen to mangle the data on thee way through.
>>
>> John Savard wrote:
>>
>>> And if memory bandwidth issues make Cray-style vector machines
>>> impractical, then wouldn't it be even worse for GPUs?
>>
>> a) It is not pure BW but BW at a latency less than K. CRAY-1 was
>> about 16-cycles (DRAM)

> DRAM for CRAY-1 doesn't sound right. Intel made 1024-bit DRAM in 1970,
> but it was pretty flaky and not very fast. I think the CRAY-1 used
> Fairchild 10K ECL 10ns SRAM.

That was CRAY-1s s stands for SRAM.

Also note 16 cycles at 12.5ns (200ns) is plenty of time for even
early RAS/CAS DRAM.

> Andrew,

According to Thomas Koenig <tkoenig@netcologne.de>:
>> Like, seemingly, the smallest point of computers was seemingly things
>> like the 6502 and similar...
>
>That was probably the PDP 8/S, which had (if Wikipedia is to be
>believed) around 519 logic gates. The 6502 had more.

I can believe it. The PDP-8 was a simple architecture and the S stood
for bit Serial, and Stupendously Slow.

--
Regards,
John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly

On Sat, 27 Apr 2024 11:48:03 -0000 (UTC), Thomas Koenig wrote:

> If people make the claim that GPUs are more power-efficient than CPUs,
> yes, they are for equal performance (if they can be programmed
> efficiently enough for the application at hand). In practice, this will
> not be used for energy savings, but for doing more calculations.

“Rebound effect”, I think it’s called.

Remember all those science-fiction predictions from the earlier part of
the 20th century, about cities on the Moon, personal flying transportation
and all the rest of it? All that was predicated on having large sources of
power--i.e. atomic power.

Instead of having atomic-scale sources of power at our disposal, we got
information processing (computers) instead, and almost nobody saw how big
a revolution that would be. Meanwhile, the atomic-energy industry seemed
to take a wrong turn, putting more effort into power production systems
that would also aid the production of atomic weapons, instead of
concentrating on predominantly peaceful technologies.

Now the information processing power is reaching the limits of the
available physical power. The only way to make significant further
progress is to start boosting that physical power generation again.

> Same thing happend with steam engines - Watt's engines were a huge
> improvement in fuel efficiency over the previous Newcomen models, which
> led to much more steam engines being built.

Watt’s engine (like Newcomen’s one before it) was an “atmospheric” engine:
the pressure to drive it came from the atmosphere, not from the steam.

True high-pressure “steam” engines were developed by Trevithick and
others, after Watt’s patent had expired and he could no longer stop them.

And that is what kicked off the Industrial Revolution.

On Sat, 27 Apr 2024 16:41:19 -0000 (UTC), John Levine wrote:

> According to Thomas Koenig <tkoenig@netcologne.de>:
>
>>That was probably the PDP 8/S, which had (if Wikipedia is to be
>>believed) around 519 logic gates. The 6502 had more.
>
> I can believe it.

You can probably find detailed schematics, on Bitsavers or elsewhere, to
confirm it. DEC published that sort of thing as a matter of course, back
in those days.

According to Lawrence D'Oliveiro <ldo@nz.invalid>:
>>>That was probably the PDP 8/S, which had (if Wikipedia is to be
>>>believed) around 519 logic gates. The 6502 had more.
>>
>> I can believe it.
>
>You can probably find detailed schematics, on Bitsavers or elsewhere, to
>confirm it. DEC published that sort of thing as a matter of course, back
>in those days.

The logic diagrams are in the back of the maintenance manual which
Bitsavers does have, but at the moment I don't feel like going through
and counting the gates.

--
Regards,
John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly

Thomas Koenig <tkoenig@netcologne.de> writes:

> BGB <cr88192@gmail.com> schrieb:
>
>> Say, seemingly no one built an 8/16 bit mainframe,
>
> The IBM 360/30 and 360/40 actually had a 8 and 16-bit
> microarchitecture, respectively. Of course, they hid it cleverly
> behind the user-visible architecture which was 32 bits.
>
> But then, the Nova was a 4-bit system cleverly disguising itself
> as a 16-bit system, and the Z80 had a 4-bit ALU, as well.
>
>> or say using 24-bit
>> floats (Say: S.E7.F16) rather than bigger formats, ...
>
> Konrad Zuse used 22-bit floats.
>
>> Like, seemingly, the smallest point of computers was seemingly things
>> like the 6502 and similar...
>
> That was probably the PDP 8/S, which had (if Wikipedia is to be
> believed) around 519 logic gates. The 6502 had more.

The LGP-30 had 113 tubes and 1450 diodes. The transistorized
successor, the LGP-31, had about 460 transistors and about
375 diodes (all per the wikipedia article on the LGP-30).

Thomas Koenig <tkoenig@netcologne.de> writes:

> John Savard <quadibloc@servername.invalid> schrieb:
>
>> On Thu, 25 Apr 2024 05:39:55 -0000 (UTC), Lawrence D'Oliveiro
>> <ldo@nz.invalid> wrote:
>>
>>> On Wed, 24 Apr 2024 23:10:47 -0600, John Savard wrote:
>>>
>>>> One of the things that those supercomputers that _do_ include
>>>> GPUs are praised for is being energy-efficient.
>>>
>>> That I never heard before. I heard it in relation to ARM CPUs,
>>> yes, GPUs, no.
>>
>> Here's one example of an item about this:
>>
>> https://www.infoworld.com/article/2627720/
>> gpus-boost-energy-efficiency-in-supercomputers.html
>
> Compared the late 1950s, was the total energy consumption by
> computers higher or lower than today? :-)

Total energy consumption by computers in the 1950s was lower
than today by at least a factor of 10. It wouldn't surprise
me to discover the energy consumption of just the servers in
Amazon Web Services datacenters exceeds the 1950s total, and
that's only AWS (reportedly more than 1.4 million servers).

On Thu, 25 Apr 2024 17:49:11 -0000 (UTC), Thomas Koenig
<tkoenig@netcologne.de> wrote:

>John Levine <johnl@taugh.com> schrieb:
>
>> I mean, my entire house is wired for 24KW and usually runs at more
>> like 4KW including a heat pump that heats the house.
>
>Good thing you're not living in Germany, your electricity bill
>would be enormous...

Possibly John meant to say "4Kwh", which actually would a be a bit on
the high side for the *average* home in the US.

If he really meant 4Kw continuous ... wow!

George Neuner wrote:
> On Thu, 25 Apr 2024 17:49:11 -0000 (UTC), Thomas Koenig
> <tkoenig@netcologne.de> wrote:
>
>> John Levine <johnl@taugh.com> schrieb:
>>
>>> I mean, my entire house is wired for 24KW and usually runs at more
>>> like 4KW including a heat pump that heats the house.
>>
>> Good thing you're not living in Germany, your electricity bill
>> would be enormous...
>
> Possibly John meant to say "4Kwh", which actually would a be a bit on
> the high side for the *average* home in the US.
>
> If he really meant 4Kw continuous ... wow!
>
Here in Norway we abuse our hydro power as our primary house heating
source, in our previous home we used about 60K KWh per year, which
corresponds to 60K/(24*365.24) = 6.84 KW average, day & night.

This was in fact while having a heat pump to handle the main part of the
heating needs.

The new house, which is from the same era (1962 vs 1963), uses
significantly less, but probably still 30-40K /year.

Electric power used to cost just under 1 NOK (about 9 cents at current
exchange rates), including both primary power cost and transmission
cost, but then we started exporting too much to Denmark/Sweden/Germany
which means that we also imported their sometimes much higher power prices.

Terje

--
- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"

On 4/29/2024 1:13 AM, Terje Mathisen wrote:
> George Neuner wrote:
>> On Thu, 25 Apr 2024 17:49:11 -0000 (UTC), Thomas Koenig
>> <tkoenig@netcologne.de> wrote:
>>
>>> John Levine <johnl@taugh.com> schrieb:
>>>
>>>> I mean, my entire house is wired for 24KW and usually runs at more
>>>> like 4KW including a heat pump that heats the house.
>>>
>>> Good thing you're not living in Germany, your electricity bill
>>> would be enormous...
>>
>> Possibly John meant to say "4Kwh", which actually would a be a bit on
>> the high side for the *average* home in the US.
>>
>> If he really meant 4Kw continuous ... wow!
>>
> Here in Norway we abuse our hydro power as our primary house heating
> source, in our previous home we used about 60K KWh per year, which
> corresponds to 60K/(24*365.24) = 6.84 KW average, day & night.
>
> This was in fact while having a heat pump to handle the main part of the
> heating needs.
>
> The new house, which is from the same era (1962 vs 1963), uses
> significantly less, but probably still 30-40K /year.
>
> Electric power used to cost just under 1 NOK (about 9 cents at current
> exchange rates), including both primary power cost and transmission
> cost, but then we started exporting too much to Denmark/Sweden/Germany
> which means that we also imported their sometimes much higher power prices.
>

Where I am living, much of the time winters are mild enough that one can
use a desktop PC as a space heater... And fire up some computationally
intensive tasks to heat the room...

The leaves and grass may turn yellow, but otherwise mostly OK. If one
gets lucky enough, maybe it might snow on Christmas, because otherwise
it is kinda lacking if it is just bare lawn (though, I think there is
some sort of spray-foam fake-snow that some people use; not sure what it
is exactly, seemingly dissolves away if it rains).

However, much of the rest of the year needs air conditioning...
I suspect most of the power use goes into running the air conditioner,
but things are rather unpleasant without an air conditioner (or, I
guess, it is like a heat pump, but sends the heat outside to make ones'
house colder).

Except when it gets cold:
Last winter, at one point it got extra cold, and the heater in my
machine shop failed (it was an electric powered furnace).

Where, say, to make heat in the winter, the furnace has a large
electrical resistance element that gets hot (like in a toaster, but a
lot bigger). As far as I know, this is a fairly common heating
technology around here.

It was cold enough that all the flood coolant in the CNC mill froze, and
most of the oils in the shop became dense and viscous.

A bucket of water also turned into a solid chunk of ice.

Almost sort of surreal, and also somewhat unpleasant to work in...

Also, in winter time, in times when it snows, the roads become rather
dangerous, with cars skidding out and sliding off the road all over the
place, etc. Often pretty much everything shuts down on these days.

Say, on most days, a person can stop at a traffic light, say, 50 MPH /
105 km/h to stop in, say, 50ft/15m, but like, this doesn't work on snow,
and the cars are prone to slide and spin out instead, etc...

Well, and all the oversize pickup trucks and 4 wheel-drive and similar
doesn't really help on snow either, ... (I am living in an area where
the roads are mostly full of large pickup trucks, with sedan-style cars
as a relative minority).

Bonus points if the pickup is lifted, has smoke-stack exhaust pipes, and
step ladders (to allow access to the doors), ...

Though, most of the time, winter isn't cold enough to cause water to
freeze solid.

Like, usually around 50F/10C or so in winter, vs ~ 90-110F / 32-44C in
the summer, or say 122F / 50C on extra hot days.

Well, and also tornadoes are semi-common... But, there are siren towers
that come on (and are fairly loud) whenever a tornado is in the general
area.

Well, and sometimes for just strong wind, like say when wind decides to
randomly pick up to 150MPH / 240km/h and knock over many of the trees
and power lines and similar (and taking a lot of roofs and flipping cars
and similar in the process), and like knocking out power to much of the
city... Had fun times with this last year (around June).

....

Where, I guess I can note that most power transmission around here
basically has the power lines on top of large wooden poles (and then for
each house, wires go from the poles down into large metal pipes that
stick up off the sides of houses, and then down to the power meter and
circuit-breaker boxes, often mounted to the outside of the houses).

Where, say, most devices run on 115-120 VAC 60Hz, but the power coming
into the house is 230-240VAC with a center "neutral" tap. But typically
only specialized appliances, like stoves and clothes dryers (or the AC /
Furnace), have access to 240V power.

Not really sure what everything is like in Europe.

> Terje
>

According to George Neuner <gneuner2@comcast.net>:
>On Thu, 25 Apr 2024 17:49:11 -0000 (UTC), Thomas Koenig
><tkoenig@netcologne.de> wrote:
>
>>John Levine <johnl@taugh.com> schrieb:
>>
>>> I mean, my entire house is wired for 24KW and usually runs at more
>>> like 4KW including a heat pump that heats the house.
>>
>>Good thing you're not living in Germany, your electricity bill
>>would be enormous...
>
>Possibly John meant to say "4Kwh", which actually would a be a bit on
>the high side for the *average* home in the US.

Last month we used 92 KWh/day, which is 3.8KW. The ground source heat
pump is how we heat the house and it was a fairly cool month. We also
have a separate heat pump for hot water (tying it to the main system
was absurdly expensive) and an induction stove which can use up to
10KW.

During the summer we use a lot less power. On the other hand, our
bills for gas, propane, and fuel oil are zero.

FWIW we pay about 12c/kwh which is fairly low for the U.S., with a
complicated remote net metering discount in which we pretend that part
of a solar farm in a nearby town is on our roof.

--
Regards,
John Levine, johnl@taugh.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly