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/gcsebi...ity_and_magnetism/mains_electricityrev7.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/products/specs/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?op=modload&name=Sections&file=index&req=viewarticle&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/...guage_s=2&url_place=product_list&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.
