How much mains power does a modern systen unit need?
- posted
17 years ago
How much mains power does a modern systen unit need?
Chip power consumption figures are published by their manufacturers.
Trust me, they will require the same amount of power, wherever you are. Only the pricetag will change.
65 to 70 is very decent for a CRT. If you want to save in this field, look for a TFT.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.
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.
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.
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.
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+).
It'll be close enough to what you already have, maybe 10W more on average.
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.
" How much mains power does a modern systen unit need? "
" 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:
" 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.
One other big factor is the move towards Active PFC (Power Factor Correction) in PSUs.
" 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+.
- 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
- 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.
very nice post, good work
It overstates the power consumption of some items considerably.
Such as?
Hard drives are one obvious example.
For HD I stated... o 7200rpm 3.5" -- 10W at idle, some more, 20-25W maximum o 10000rpm 3.5" -- assume 30W re cooling needs
7200rpm 3.5" manuf'r specs... o Current hard drives---- smallest capacity -- 7.50W idle, 12.5W active
---- largest capacity -- 9.30W idle, 13.3W active
---- variable quality -- 8.10W idle, 13.6W active o Older HDs can have somewhat higher figures o Overall I would still take 10W at idle, 20W max if older HD
10000rpm 3.5" manuf'r specs... o Current hard drives---- high performance actuator -- idle 7.9W, 8.4W active
---- very high performance actuator -- idle 12.2W, 17.4W active o Trends
---- 1) higher performance actuators to justify price premium (watts)
---- 2) silicon disks forcing higher cache on electromag disks (watts) o Overall I would still assume 30W re cooling needs
In terms of energy usage the confounding factor in PCs is not the HD/RAM/Optical or even CPU (P4 Prescott 115W v Conroe 50W). It is the actual GPU fitted - integrated may be 10W, whereas a high end card can draw well over 100W & idle not far off that figure.
Saving 50W by choosing a very pricey m/b & chip does not gain much if you also u/g the graphics card to one drawing 50W more.
Likewise a CD-ROM may draw only a few watts, but a high end DVD-R/RAM/CDR writer multi-drive can draw 18-25W at peak. Yes CPUs can draw a lot of power - but so do other devices.
My setup at 50% CPU load and HD read/write pulls ~245 Watts (as reported by my UPS). System specs below.
-Abit AV8
-AMD64 X2 3800+ (overclocked but stock voltage)
-512 MB of PC3200
-3 IDE HDs + 1 USB External
-Idle DVD-R
-17" CRT
-80mm System fan
-GeForce3 Ti200 AGP (active cooling)
-Antec 420W PSU
*Other Items pilling power from same UPS-Cable Modem & Wireless Router
-HP All-in-One (idle)
-2.1 Speaker system (idle)
Based on these numbers, I would assume that my actual PC pulls ~200 watts or slightly less. Its not a gaming rig, but the most likely upgrades (more RAM and newer AGP card) would likely add less than 50 Watts.
While a quality power supply of the proper wattage is very important, I would venture that most users need less than 300 Watts and very few require more than 400. Keep in mind that I've no experience with more modern/power hungry video cards.
-Dylan C
And that is overstating it.
And that is too.
Bad assumption.
Those are overstated on the idle.
God knows what 'variable quality' is about.
Pity that none of the other numbers are with older hardware.
Nothing like your previous 30W
Waffle.
More fool you.
That last is a good example of the problem with your original and you didnt even mention the AMD cpus.
Again, nothing like your original.
Having fun thrashing that straw man ?
Not very often tho.
Duh.
o Go to any of the HD maker websites o Download the manufacturers specification o Read it.
Stick an ammeter on a current Barracuda & older Barracuda. Do not use the 2A fused range during startup obviously.
PCs have a range of wattage draw re idle/loaded... o Base end office Cel2.0, integrated graphics, 1 HD, 1 optical o idle -- 85W with 17" TFT, 95W with 19" TFT o load -- 120W for 17" TFT, 130W with 19" TFT
You really are a troll.
HD spec of 8-17W can not be applied to cooling needs... o 8-17W is not distributed evenly over the whole drive
---- a HD is Actuator, Spindle Assembly, PCB Components o 8-17W may be focused in specific components
---- with specific maximum operating temps
---- requiring specific linear feet per min of airflow o Providing cooling for 8-17W ignores local needs
---- thermal shadowing by other components
---- thermal shadowing by case design & HD positioning
Stick 2x 10,000rpm HD against one another in a drive cage. Provide sufficient cooling for 2x 8-17W drives.
I will provide the data recovery firm name to use... o Motor-IC overheats from lack of linear-feet-per-min airflow o Motor-IC dumps heat into surroundings, motor/spindle heat o Motor-spindle dumps heat into FDB accelerating aging o FDB aging causes higher current draw (startup & continuous)
---- S.M.A.R.T. data measures startup Ima &/or startup Tsecs o Higher current draw heats motor/spindle & Motor-IC
---- Reinforcing System Loop of increasing thermal dissipation
Same thing happens more slowly with HDs anyway - hence the older a HD the higher the startup current & higher op current.
Add another HD because the old one is too small, fit them too close & you can accelerate the demise of the old one by temps.
I would assume 30W re cooling needs for 10k-rpm HDs. You can assume what you wish.
???
Yes but you have to assume it at SOME point re 1) cooling 2) PSU.
???
Ah now I see. Intel tend to be worst case from a thermal perspective.
Datasheet numbers are worst case numbers and STILL most arent 10W with current desktop drives.
What makes a lot more sense is
In spades with the max number.
There might just be a few more drives around than those.
Irrelevant to that bit about DVD-R/RAM/CDR writers.
You really are a pathetic excuse for a bullshit artist.
Depends entirely on the case design.
Irrelevant to your silly claim about 30W
Irrelevant to your silly claim about 30W
Irrelevant to your silly claim about 30W
Only the stupid do something as stupid.
Or dont have them adjacent, stupid.
I'm not stupid enough to need them.
Only in that terminally stupid config.
Only the stupid do things that stupidly.
You can assume anything you like. Anyone with a clue doesnt use such a stupid config.
I dont assume, I measure, thanks.
Its a very simple sentence, even you should be able to manage it.
Nope.
Wrong, as always.
Bingo.
You wouldnt know what a troll was if it had its fangs in your lard arse, child.
You certainly fit the picture.
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