True power, power unit

what is the different of True power (power unit) and normal power unit. My friend told me that the true power unit example 400W, when it is on low load or  high load will draw all the full power 400W. is this true. show me some prove  (Antec 480W True PSU)
kianhowAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

nobusCommented:
This is NOT true.
Each power supply has an efficiency ratio, varying from 60% for really bad ones, to up to in the 90-ies for good ones
BTW Antec  and Enermax are well rated ones
More info :
http://www.gillware.com/            
http://www.tomshardware.com/2004/01/22/getting_the_right_power/

to answer your Q : it will draw a tiny percent + actual load - the percent depends on the efficiency
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
nobusCommented:
i forgot : get a new friend (who verifies his facts before telling them)
0
MarkCommented:
The PSU will put out 400w when it is at maximum output, if the computer needs 200w it will output 200w. The efficiency has less to do with it as it is already incorporated into the amount of Watts the PSU can output.
If you have a 70% efficiency the PSU will output say 400watts at max but the power draw into the PSU from the wall outlet will be 571w. the 30% loss is generated as heat from the PSU(heat is energy too) thats why they have heatsinks in them.
There are PSU's that are more efficient than others, seasonic for example rate their PSU's at 80% efficiency but have been known to be capable of 95% under ideal conditions.

Now onto the question at hand.
Does a PSU constantly output the 400W its rated for-->NO and here is the link that shows how each component fron CPU to cd drive and everything inbetween changes its electrical draw under different situations, from idle to maximum.
http://www.silentpcreview.com/article265-page1.html

No need to get a new friend, just slam him with the facts next time you see him. Much more fun than just getting rid of him.
0
nobusCommented:
what's the difference , sparkmaker  ? (quite fitting for power supplies :-))   )
0
MarkCommented:
Can't humiliate a PSU, but a friend, definately.
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Components

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.