Typical mains power for mid-range PC?

How much mains power does a modern systen unit need?

----

In more detail ... I am in the UK.

My existing PC (socket-A 462-pin cpu with 768 MB SD-RAM) uses about 180
Watts at 240 volts of which about 65 or 70 Watts is to power my CRT.
Printers and scanners would be extra.

Modern cpu's seem to be quite power hungry.

QUESTION: Approx how much mains power is likely to be needed for a
modern mid-range AMD-based PC? I don't know the existing AMD processors
but something average to middling is what I mean.

QUESTION: Would a sysem based on an Intel cpu need less power?

Jon D wrote:
How much mains power does a modern systen unit need?

----

In more detail ... I am in the UK.

My existing PC (socket-A 462-pin cpu with 768 MB SD-RAM) uses about 180
Watts at 240 volts of which about 65 or 70 Watts is to power my CRT.
Printers and scanners would be extra.

Modern cpu's seem to be quite power hungry.

QUESTION: Approx how much mains power is likely to be needed for a
modern mid-range AMD-based PC? I don't know the existing AMD processors
but something average to middling is what I mean.

QUESTION: Would a sysem based on an Intel cpu need less power?

Chip power consumption figures are published by their manufacturers.

--
Sue

On Fri, 21 Jul 2006 09:43:36 +0100, Jon D wrote:

How much mains power does a modern systen unit need?

----

In more detail ... I am in the UK.

Trust me, they will require the same amount of power, wherever
you are. Only the pricetag will change.

My existing PC (socket-A 462-pin cpu with 768 MB SD-RAM) uses about 180
Watts at 240 volts of which about 65 or 70 Watts is to power my CRT.

65 to 70 is very decent for a CRT. If you want to save in this
field, look for a TFT.

Printers and scanners would be extra.

Modern cpu's seem to be quite power hungry.

Modern users are (CPU-)power hungry.
There is no free lunch, not even in processor-land.
You need to put energy in to get anything out.

QUESTION: Approx how much mains power is likely to be needed for a
modern mid-range AMD-based PC? I don't know the existing AMD processors
but something average to middling is what I mean.

There is no middling. Depends on how your PC is built and how you
use it. Some PCs switch down their CPU on low loads. But that
wouldn't do any good if you keep your PC busy.

QUESTION: Would a sysem based on an Intel cpu need less power?

No. Generally speaking, Intel is not your choise if you want to
conserve energy.

--
Kind regards,
Gerard Bok

Gerard Bok wrote:
On Fri, 21 Jul 2006 09:43:36 +0100, Jon D wrote:


How much mains power does a modern systen unit need?

----

In more detail ... I am in the UK.


Trust me, they will require the same amount of power, wherever
you are. Only the pricetag will change.


My existing PC (socket-A 462-pin cpu with 768 MB SD-RAM) uses about 180
Watts at 240 volts of which about 65 or 70 Watts is to power my CRT.


65 to 70 is very decent for a CRT. If you want to save in this
field, look for a TFT.


Printers and scanners would be extra.

Modern cpu's seem to be quite power hungry.


Modern users are (CPU-)power hungry.
There is no free lunch, not even in processor-land.
You need to put energy in to get anything out.


QUESTION: Approx how much mains power is likely to be needed for a
modern mid-range AMD-based PC? I don't know the existing AMD processors
but something average to middling is what I mean.


There is no middling. Depends on how your PC is built and how you
use it. Some PCs switch down their CPU on low loads. But that
wouldn't do any good if you keep your PC busy.


QUESTION: Would a sysem based on an Intel cpu need less power?


No. Generally speaking, Intel is not your choise if you want to
conserve energy.

Take a look at the Core-2 processors, such as the E6400.

--
Sue

Gerard Bok wrote:

On Fri, 21 Jul 2006 09:43:36 +0100, Jon D wrote:



QUESTION: Would a sysem based on an Intel cpu need less power?

No. Generally speaking, Intel is not your choise if you want to
conserve energy.

Nonsense, there is no generalisation! Intel has power hungry Prescott
P4 and derivatives and low power Pentium M and very power efficient
new generation Core 2 Duo (Conroe); the latter is the way to go for a
new system.

How much mains power does a modern systen unit need?

CPUs...
o P-3 -- 30-35W
o P-M -- 25-35W
o P4 Celeron 2.0 -- 58W
o P4 3.2Ghz 800fsb HT Northwood -- 82W
o P4 Prescott -- 115W+

Graphics...
o Onboard -- 10-20W for low end, 50W+ for higher end
o Add in Card -- 10W for low end, 100W+ for high end

RAM...
o 1GB in 1 DIMM consumes 10W, generally assume 15W
---- so an 8GB PC is needs a RAM-VRM able to supply 100W
o 1GB in 4 DIMM can consume 30W or more
---- RAM slots historically limited as much re RAM-VRM Watts

HD...
o 7200rpm 3.5" -- 10W at idle, some more, 20-25W maximum
o 10000rpm 3.5" -- assume 30W re cooling needs

Optical
o Writing -- 25W a typical benchmark figure (a lot really)

Ensure MS File Indexer is not running in the background, or spyware.
Either can cause an elevated baseline power usage.

For systems...
o Base end office Cel2.0, integrated graphics, 1 HD, 1 optical
---- idle -- 85W with 17" TFT, 95W with 19" TFT
---- load -- 120W for 17" TFT, 130W with 19" TFT
o Apple Dual G5, multiple HDs, 20" TFT, optical, 4GB
---- load -- 325-350W
o Dual Xeon, multiple HDs, 20" TFT, optical, 4GB
---- load -- 450W

If you are using a CRT, an equivalent TFT is uses 70% less watts.
A 21" CRT is around 95-115W, a 19" TFT is around 35W (the big
factor in TFTs is how bright you have the backlight obviously :-)

As for upgrading just for energy saving, the payback period would
be longer than the actual energy saved even if run 24/7 at full load.
Core 2 Duo are essentially a "desktop P-M" re efficiency, but the
boards are very expensive as are the CPUs (compared to lower end).
Good value versus a Mac G5, not good value if just to save watts.

If not being used, at least power the CRT/TFT off and ensure
no screen savers running keeping the CPU from idling.

Athlon XP, Northwood P4 have a quite low idle wattage.
Prescott P4 by comparison have a very high idle wattage (50W+).
--
Dorothy Bradbury

On Fri, 21 Jul 2006 09:43:36 +0100, Jon D
wrote:

How much mains power does a modern systen unit need?

----

In more detail ... I am in the UK.

My existing PC (socket-A 462-pin cpu with 768 MB SD-RAM) uses about 180
Watts at 240 volts of which about 65 or 70 Watts is to power my CRT.
Printers and scanners would be extra.

Modern cpu's seem to be quite power hungry.

QUESTION: Approx how much mains power is likely to be needed for a
modern mid-range AMD-based PC? I don't know the existing AMD processors
but something average to middling is what I mean.

It'll be close enough to what you already have, maybe 10W
more on average.



QUESTION: Would a sysem based on an Intel cpu need less power?

Depends on what you buy. Averaging Intel's entire line of
CPUs including Core 2 Duo, it'll be close enough to the AMD
alternative.

Intel's newest CPUs use less power but then their chipsets
use more, and then they want to focus on performance per
watt instead of watt per system. Nobody buys 1.3 systems so
it has to be performance per system if the important factor
is how much power a small number of systems uses.

In short, ignore power usage on normal (equivalently
equipped) desktops, if power usage is that important then
neither choice is suitable.

Jon D wrote:

" How much mains power does a modern systen unit need? "

http://extreme.outervision.com/psucalculator.jsp


" My existing PC (socket-A 462-pin cpu with 768 MB SD-RAM) uses about
180 Watts at 240 volts of which about 65 or 70 Watts is to power my CRT.
Printers and scanners would be extra. "

The CRT, printer and scanner should have their own power units
independent of the PC's PSU.

Make a list of everything that isn't powered by the PC's PSU. Find the
specs on the manufacturer's websites and add them to the total wattage
you need for the PC PSU (see aforementioned link to calculator). Work
out the total wattage, divide by 1000, then times by 0.0633 (averagely
high cost of electricity) . That will tell you the approximate maximum
costs to run your PC each hour (in £s).

By that logic, a total of 470W would cost less than 3 pence per hour (
(470 / 1000) * 0.0633 = 0.029751)

Cost of electricity: http://www.ukenergy.co.uk/pages/calculation.html

http://www.bbc.co.uk/schools/gcsebit...cityrev7.shtml

Bear in mind that, in reality, the cost will be considerably less than
that, as much of the setup would not be running constantly and under duress.


" Modern cpu's seem to be quite power hungry. "

Yes and no. It depends how you look at the argument. They have more
capabilities than previous generations of CPUs, but big steps have been
made in nanometre architecture. From the dawn of the Athlon XP the
process has gone from 180nm to 130nm to 90nm and now towards 65nm.

If you were to re-encode the same 2 hour video on both an Athlon XP and
an Athlon 64 X2 you would find that the Athlon 64 X2 would be using more
power, but it would also do the task considerably faster. If a system
uses twice the power, but does the task in half the time, what's the
difference? You would only end up using more power by using your PC
more (which often becomes the case)

Modern systems can use considerably more power for games because the
graphics cards and CPUs can output more frames per second (FPS). If
everyone set their systems to limit the FPS they would find their power
usage to be lower. However, most people don't do this, allowing their
systems to use as much power and capability as their components will
give them.

DDR2 actually uses less power than DDR(1), but yet operates at higher
bandwidths.
http://www.corsairmemory.com/corsair...s/ddr2_faq.pdf

Another area of power consumption has been the rise in spindle speed for
hard drives. The rise from 5400rpm to 7200rpm has been a large factor
in power increases, and many people even have 10,000rpm hard drives in
their desktop systems now. However, as with other components, steps
have been made to limit the power used by read/write operations.

One other big factor is the move towards Active PFC (Power Factor
Correction) in PSUs. http://www.endpcnoise.com/cgi-bin/e/pfc.html


" Approx how much mains power is likely to be needed for a modern
mid-range AMD-based PC? I don't know the existing AMD processors but
something average to middling is what I mean. "

Mid-range means different things to different people. CPU speeds often
dictate how "modern" a PC is, but everyone has different requirements in
their RAM requirements, graphics card usage/capabilities and the
size/number of hard drives they wish to use. Everyone also has
different amounts of add-on equipment and other stuff.


" Would a sysem based on an Intel cpu need less power? "

Not necessarily. Intel came under some criticism because their 90nm
desktop Prescott CPUs used more power than the equivalent AMD CPUs which
were still at 130nm. However, Intel have had more success recently with
65nm, and it's not like all Intel CPUs use more power than all AMD CPUs.


If you're that worried about power consumption you could opt for a 35W
Athlon 64 X2 3800+.
http://www.amdzone.com/modules.php?o...icle&artid=257

You'll find that article quite interesting where it states the total
power output under load as being 82W, but don't think for a minute that
you only need use a 100W PSU. In the review above they use a 500W
CoolerMaster iGreen.
http://www.coolermaster-europe.com/i...t&p_class=1114

With the following components you could have a gaming PC that will
certainly last for a couple of years (or even longer), and which uses a
little less power than the comparable systems:

- AMD Athlon 64 X2 3800+ 35W AM2 ADD3800IAA5CU
(see previous review)
- Asus M2N32-SLI Deluxe motherboard
(just because it's currently the best AM2 motherboard)
- Corsair XMS2 2x1GB DDR2-800 TWIN2X2048-6400
(1.9v operating voltage is low for DDR2-800)
- Nvidia GeForce 7900GT 256MB
(hits a sweet spot with power/performance
http://www.vr-zone.com/?i=3335&s=8 )
- Seagate Barracuda 7200.10 320GB ST3320620AS
(lots of storage, sweet spot in price, reliable, 5 year warranty)
- CoolerMaster iGreen 430W RS-430-ASAA
(see aforementioned link to CoolerMaster website)

....and just as important, add an LCD TFT monitor.

"Dorothy Bradbury" wrote in message
...
| How much mains power does a modern systen unit need?
.....
| Dorothy Bradbury

very nice post, good work

Jon D wrote:

QUESTION: Approx how much mains power is likely to be needed for a
modern mid-range AMD-based PC? I don't know the existing AMD
processors but something average to middling is what I mean.

QUESTION: Would a sysem based on an Intel cpu need less power?

Numbers culled from many years of review-analysis:

idle load
AXP 2800+ (Barton) 45W 70W
A64 3000+ (130nm) 20W 60W
A64 3200+ (90nm) 10W 30W
A64 X2 3800+ 20W 50W

These figures are for the CPU itself, quoted without CnQ, which roughly
halves idle power. Note that ATX PSUs are usually inefficient at 100W
power draw, so as much as 30-50% of mains power may be wasted in the PSU.

As for Intel, Prescott-based CPUs use much more power per core at both
idle and load. The new Conroe cores appear to use more power at idle but
less at full load than the X2s. SOI does still appear to have an idle
power advantage.


You can get a whole Sempron-based VIA IGP system box into less than 60W
idle mains draw. Less than that is difficult because of PSU
inefficiency. If you add an nForce4 chipset and a decent video card,
mains idle power consumption will approach 100W.


--
John Jordan