Can I get a explaination on how power supplies dies or how the unit of measurement works?

[Sun Mei]

Say I am using a Thermaltake AC0015 Dr. Power II Power Tester it says
{Designed from the ground-up to support every ATX power supply available today up to ATX12V v2.3.
Oversized LCD panel that accurately shows the value of each specific power rails (within one-tenth of a volt).
Accurate voltage indicating for +12V/+5V/+3.3V/5VSB/-12V.}

What does what number mean? +12V/+5V/+3.3V/5VSB/-12V.

Previous I though power supplies are only measured in watts and when it ages , the watt count goes down with time and making it unusable. So say 500 watt max power supplies 3 years later 450 max watt left. Now I have a feeling I am wrong.

So what number can indicate the power supply is failing , if I had the Thermaltake Power Tester

 

[beefy]

Hi,

In a pc it has different needs of voltage,each one must be at -+5% so the reading you wrote above are ideals and when you use the psu test it will show actual values and they must be within -+5%,your meter will show if any voltage are within the -+5% by changing the back light to red for fail if they stay blue all good.

 

[Math Geek]

your wall outlet is 110 volts which is WAY too much for pc parts to handle. the power supply takes this 110 volts and "transforms" it into smaller amounts. this is the 3v, 5v, 12v etc you are asking about. different parts of the pc use different amounts of power. so the mess of wires coming out of it are all different voltages for the different parts.

the main motherboard power and gpu power (others as well) are 12 volts. this is why most of the wattage goes to the 12 volt rails. fans, cpu, hdd's and such run on smaller watts.

volts is not as important as amps available on the rails, especially 12 v. the formula looks like this amps = watts / volts or solved for watts, then watts = amps * volts. so if your 12 v rail has 30 amps, then 30 * 12 = 360 watts you can get from it and no more.

this is why you will see the first answer to "what gpu can i run?" will be "what psu do you have and what's its 12 v amps?" (or if they are not asking this, then ignore the rest as it may be inacurate) the focus is on 12 v since the main pieces run from this rail. the others are usually good enough and generally ignored. if your psu does not provide enough amps, then it won't run the card.

as for life of a psu, this will vary. a solid quality psu from a top manufacturer should not lose very much over time. it will lose some but it's not like a battery that slowly recharges less and less until it's useless. a cheapo brand "super mega killer ultra power" 700 watt psu for $15 will probably die quickly and might take your pc (or house) with it!! this is due to the capaciters and such inside the psu that will pop, leak and all kinds of other nasty things. quality psu's use higher gauge wires that can handle the temps needed and so won't melt at full usage.

i know this is a lot of info, but it's only the tip of the iceburg. if you really want to read more about every little aspect of psu's here is a thread from tom's that will fulfill all your fantasies. http://www.tomshardware.com/forum/324368-28-computer-power-supplies-guide

 

[Sun Mei]

your wall outlet is 110 volts which is WAY too much for pc parts to handle. the power supply takes this 110 volts and "transforms" it into smaller amounts. this is the 3v, 5v, 12v etc you are asking about. different parts of the pc use different amounts of power. so the mess of wires coming out of it are all different voltages for the different parts.

the main motherboard power and gpu power (others as well) are 12 volts. this is why most of the wattage goes to the 12 volt rails. fans, cpu, hdd's and such run on smaller watts.

volts is not as important as amps available on the rails, especially 12 v. the formula looks like this amps = watts / volts or solved for watts, then watts = amps * volts. so if your 12 v rail has 30 amps, then 30 * 12 = 360 watts you can get from it and no more.

this is why you will see the first answer to "what gpu can i run?" will be "what psu do you have and what's its 12 v amps?" (or if they are not asking this, then ignore the rest as it may be inacurate) the focus is on 12 v since the main pieces run from this rail. the others are usually good enough and generally ignored. if your psu does not provide enough amps, then it won't run the card.

as for life of a psu, this will vary. a solid quality psu from a top manufacturer should not lose very much over time. it will lose some but it's not like a battery that slowly recharges less and less until it's useless. a cheapo brand "super mega killer ultra power" 700 watt psu for $15 will probably die quickly and might take your pc (or house) with it!! this is due to the capaciters and such inside the psu that will pop, leak and all kinds of other nasty things. quality psu's use higher gauge wires that can handle the temps needed and so won't melt at full usage.

i know this is a lot of info, but it's only the tip of the iceburg. if you really want to read more about every little aspect of psu's here is a thread from tom's that will fulfill all your fantasies. http://www.tomshardware.com/forum/324368-28-computer-power-supplies-guide

So its all about the amp per rail , all theses years I have been only looking at at watts , no wonder why my old pc power supply couldn't handle the new graphic cards , it was a cheap PSU and im guessing the 12 rail was too weak

Thanks for the information , appreciate it a lot

 

[Sun Mei]

Hi,

In a pc it has different needs of voltage,each one must be at -+5% so the reading you wrote above are ideals and when you use the psu test it will show actual values and they must be within -+5%,your meter will show if any voltage are within the -+5% by changing the back light to red for fail if they stay blue all good.

Got it thanks for the quick tip

 

[Sun Mei]

Hmm after doing a bit of reading , it would seems those ATX power testers are useless , cause they cannot measure the power supply under load.

My PC randomly shuts down before it goes into the windows OS or sometimes it makes after the logo-> blue screen or once in twenty tries it makes it to the desktop.

Trying to test my power supply , will I require another power supply to test?

 

[beefy]

Hi,

I have the doctor power 2 and it works fine,just connect a fan to one of the sata leads to simulate load. I would use a multi meter if Ihave any concerns about a psu to just back up the reading I`m getting from the psu test. The ones that just have led lights are not so good as an led might light up between 1.7 and 3.5 volt which is way passed -+5% so if they have skimped on parts = poor readings. If you want to test a psu with a multi meter follow the link https://www.youtube.com/watch?v=ac7YMUcMjbw
doctor power I use just for a quick test to make sure psu are not so out wack as they can turn up faulty from the factory and if you ever buy a 2nd hand 1 of ebay you don`t know why it was sold and connecting it up to your $$$ new pc build it`s,well its best to air on the side of caution.

 

[Sun Mei]

Hi,

I have the doctor power 2 and it works fine,just connect a fan to one of the sata leads to simulate load. I would use a multi meter if Ihave any concerns about a psu to just back up the reading I`m getting from the psu test. The ones that just have led lights are not so good as an led might light up between 1.7 and 3.5 volt which is way passed -+5% so if they have skimped on parts = poor readings. If you want to test a psu with a multi meter follow the link https://www.youtube.com/watch?v=ac7YMUcMjbw
doctor power I use just for a quick test to make sure psu are not so out wack as they can turn up faulty from the factory and if you ever buy a 2nd hand 1 of ebay you don`t know why it was sold and connecting it up to your $$$ new pc build it`s,well its best to air on the side of caution.

However , if I use this method of testing , I can not be 100% sure that , say a video card is good enough when it is put on load. Correct?

On the other hand , if the meter say it fails , then it fails , correct?

 

[Math Geek]

so long as your not maxing out the watts you ok. a general rule i follow is to only use about 80-85% of the rated power (amps or watts) this gives that little bit of headroom to keep from killing the psu real quick. so if you have 30 amps on the 12v rail and compute 24-26 amps ish usage, then your good to go. if you compite 28 amps or more, then i'd look into another psu.

for instance i am running an r9-270 on only a 375 watt psu in the kid's pc. way below suggested levels but it has 36 amps on the 12 v rail which is well above 25-26 amps i computed for the system requirements. that's only 72% which is well below the safe zone.

do the math to be sure and you can't go wrong. i think this is why folks just opt for huge psu's. it's easier than doing the math. i guess we can't all be math geeks

 

[beefy]

Hi,
I have to agree with math geek,there are so many things that can be wrong with a psu but the doctor power 11 you have is proberly 1 of the best tester I have come across specially if you need to test a lot of psu,I looked into it when i brought mine,the reviews for it were better then most and I was not going to part with the money if I could have got one of those cheapy led ones that would do the job. In the reviews online I came across one had a dodgy psu that all the cheapy one passed as fine but when used to power anything it would cause a lot of BSOD and the doc flagged it straight away. Someone on here had a problem with his pc and I asked him to check his psu and he told me he had and posted back picture of the led tester showing pass on all connections,I said to him to do it anyway but I don`t think he had access to a multi meter so just tried it in someone elses pc and then he got back to me and comfirmed that it was the psu as the other pc went from reliable to a juat a papperweight. if you wish to understand about electric in general look up "ohms law" which will provide you with the equations you need to run the math yourself. One example of a psu i can think of was a model/brand called hyper they turn up at a very good price and people were using them fine with cards around the time of nvidia 7800gtx and they would run a 8800gtx but sli required something like 750W which the psu was rated at but everytime a game was launched the pc would stop,where it had the wattage but the ampage was low by about an amp or two. A psu is a important part of a pc and not a place to skimp on.

 

[Math Geek]

by the way, never actually bought one of those psu meters (well ok i do have a very old led tester i've had for prob 10 years or more). how would you compare it to a volt meter? i'm thinking along the lines of ease of use over the meter and such.

i work on computers a lot and use an old volt meter to check but if this doctor power is easier to use and accurate/relieble. i could be swayed to spend some cash. anything to make pc testing and such easier is worth the cost to me.

 

[beefy]

Its a lot better then the led tester,you get to see actual voltage and if it picks up anything it does not like the screen goes red.you can test just one part of the psu wiring or you can plug them all in and do a complete test. I brought a second hand xfx 850w a while back,a single rail I think they label it true power or something ,I tested it with the doc and it reported back everything was bang on,so as a second hand unit it made me get the multimeter out and it reported back within .1 of a volt. What I really like about is theres no sticking in a bent papperclip and the chance of getting a shock,you know when you got bits all over the table and you forget you have a live unit.

 

[Math Geek]

thanks will look into some of these. i knew the old led tester was not good enough, got the volt meter and never looked back. perhaps 10 years is long enough to revisit the psu tester world. will be looking into these very soon.

 

[beefy]

I forgot to mention, it also has a pg test built in. I was not sure what this was for but evently found out it can messure the time taken to power up all parts.

 

[Sun Mei]

Thanks for the help guys ,
Actually I don't have the tester but was looking into it , was just about to buy a LED one,
You swayed me the other way

Seems very useful from your high praises, beefy

 

[Math Geek]

ok so with what you just said and the kenny avator i just busted out laughing picturing stan approaching the screen and saying "see i learned something today....."


still laughing.....

 

[beefy]

lol