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300watts PSU / Alot of devices
300watts PSU / Little devices

Effectively, do both systems consume the same amount of power? i.e. You get the same amount for you bills no matter which of the above you got.

Just a thought.

well, the difference may not be measurable in kilowatt hours, but a 300W PSU in a system with only core components, may use as little as 180W of the available power. Another system may be pushing on the edge of that 300W. The difference may not be enough for a billing increase, especially if it isn't used 24/7.

A 300W PSU does not mean that it always uses 300W, that just means that it is rated at being able to produce up to 300W of power. The actual power consumed by the system is calculated by multiplying the voltage used to power each device by the actual current(amperage) draw of each device.

OOOOOHHHH!

I got it. Thanks a lot!

One more thing...you may notice that a 300W labelled PSU may not be exactly pumping out 300watts, it can be a real 275W PSU rounded off to the nearest hundred.

Some companies rate them at the Max, others nominal, and some do round up. You will find PSUs that will not reach the rating without causing problems, and you will find some that will exceed the rating. The key is to stick with quality manufacturers that stand behind their product.

I'm using a 300watt PSU for my Athlon XP 2000+ (Heard it consumes 70.5watts) and it's running fine. It isn't branded though. But I'll take your advices and take note of them in the future.

I must admit those are something which I do not know and will overlook if I wasn't adviced.

70.5 watts is about what your CPU consumes. The graphics card probably gets around 50 watts or so.

that's pathetic!

I hope my sys isn't eating too much power.

I had a GF4 Ti4200 (Which I don't know how much power it consumes), 2 CD/DVD drives and 2 Hard Disks.

I had thought about whether I will need to change my PSU when I change it from p4 to athlon xp. I thought due to the xp, there may not be enough power. Surprisingly (At least to me), the sys ran stable, so I just stick to my 300w PSU...

Unless you have 6 system fans like me, you definitely need a quality 350w PSU like Enermax or Antec with at least 25A on the 12V rail.

At least 25A?! :eek: That's overkill of the worst kind. 18A should be enough for my system, let alone yours. Just be sure to check the amperage ratings. My last 400W PSU had only 15 and it screwed me over, I always got BSODs and restarts and such. Buying an Enermax or Antec is insurance against buying a crappy PSU. You can't go wrong with either.

A lesson well learnt for me.

I just ordered a 400w PSU but I didn't pay any attention to anything other than the wattage. Hopefully it doesn't screw up.

What was the brand on it? Hopefully not Raidmax...