Is a computer power consumption constant?

[SirRiff]

Greetings,

if anybody is electronically inclined, please shed some light on this.

I got an ol puter with a 200W power supply. Does that mean that the power suppied is always 200W or up to 200W as needed. And if the compute is idleing, is there a significent reduction in power consumption?

I was just wondering because I always turn it off every night, because i want to save energy. 200W would be like leaving two 100W light bulbs on all night which is pointless. But possibly during idlying it only uses 50W or soemthing.

any info?

I also saw a review recommending 550W for any "hard core gaming machine" i guess meaning useing a 2Ghz+ processer, lots of ram, kickass video card, etc, etc. Isn't hat a bit much even for a kick ass computer? 550w? thats easily all the lighting of my apartment. that would be expensive to leave on round the clock.



SirRiff

 

[Roel]

It's not constant. Spinning 2 cd's at top speed at once will consume ALOT more than not spinning. Pure calculations will probably use less than memory access. If you got heavy videocards etc, and alot of stuff in there, it will use more power. Higher speed need more current. The cooler also uses alot too...

So, it's not constant, and the rating of the powersupply is about the max I guess. Or the maximum power that it can provide constantly over a certain timespan... Dunno. But it is a maxvalue.

leaving it in iddle condition won't consume all that much. Just turn off your monitor. or have that one running idle too...

 

[Sangram]

All computer power supplies are variable power. Which means they will consume very low power in standby or low-power state, sometimes as little as 5W.

That said, it is not possible to determine what the power consumption of your 'puter is in idle state without knowing if your hard drives, monitor etc. are on or off. For DAWs which are generally set up with ACPI off, power consumption in idle state is usually quite high (I switch mine off as I spend <2 - 4 hours with it on weekdays. Weekends it's usually on 'til I sleep.

'Green' PCs can be set up to have as little as 5 watts of power consumption in idle state. Even when you're working on the PC, surfing or typing in email consumes less power than when you're running an effect or playing a game.

550 watt PSU does NOT consume 550 watt, even at peak output. 550 is the amount of juice the PSU will deliver if all its 'rails' are loaded to max, it will be unable to deliver 555 watts. Typically the main 'rail' in a computer PSU is the 5V rail, which is the rail that feeds the CPU, memory, and PCI operating voltage, and the 12 V rail, which feeds the hard drives, fans, and peripherals. The PSU is generally judged on its capability to juice up the 5v rail, and in a modern system should not be less than 160 watt in any case. Typically requires a 350 watt PSU for this.

Therefore at peak load your PSU may be actually consuming only 80 watt from mains, and during idle maybe 50% of that, depending on your idle state. In standby (all drives shut down, all video off, no process threads) it may be about 20 watt, and in 'Green' state the PSU may be drawing only 5 watt from mains if it is set up for STR/STD operation.

 

[SirRiff]

Thanks for the info..

I figured 550W per hour just didn't make sense, no need for that kinda juice.

you would think puters would need less and less energy these days too as everything gets smaller


sirriff

 

[Slackmaster2K]

The recommendation for large power supplies does not usually come from an actual requirement of a lot of power. Very simply, a power supply typically delivers more consistant power when it is not being pushed to its rated limits. While your machine might only require a 185W supply, you might experience a lot of power problems if you actually tried to use a 185W supply! Just the increased power draw that occurs when you're playing a game would be enough to make things big time flakey.

These days a single decent 350W P4 or Athlon rated supply is more than adequate for the average machine. If you're powering 4 hard drives and 4 cdrom drives and a bunch of pci devices and a bunch of USB devices and dual processors and a bunch of case fans and so on and so forth, then *maybe* you would actually need a 550W power supply

And no, the computer will not be drawing a consistant amount of power, so moving to a larger supply should not have an impact on your power bill.

Slackmaster 2000