| View previous topic :: View next topic |
| Author |
Message |
Wookie8662
Black Belt 2nd Degree
Joined: 28 Dec 2001
Posts: 2842
Location: Downey, CA
|
 Posted: Sat Aug 21, 2004 6:31 pm Post subject: |
 |
|
Most, if not all case fans run on the +12 volt rail.
_________________
 |
|
| Back to top |
|
 |
Twisty
Black Belt 1st Degree
Joined: 02 Mar 2001
Posts: 1904
Location: UK
|
| Posted: Sun Aug 22, 2004 12:30 am Post subject: |
|
|
Unless they are 5V fans 
_________________
- Webster -  |
|
| Back to top |
|
|
kltsin
Black Belt 2nd Degree
Joined: 29 Jun 2004
Posts: 2792
Location: St. Augustine, Fl
|
| Posted: Sun Aug 22, 2004 1:02 am Post subject: |
|
|
Hmm fans...
Cpu, case and chipset fans 99.001% (I made that number up, but its realistic! ) of the time are +12v.
What you should know about having a small or cheap power supply is that when a system powers on those motors draw 3 times more than they actually use.
In fact anything with a motor has a huge power spike at initial startup, although it doesnt take much to move a fan they do draw a huge amount of amps at boot. Once a fan or motor is spinning the amps drop immensly.
But overall dont read too much into any of this.
Most power good supplies and even some cheap ones can power more than they are rated for.
A good company can sell a power supply that can exceed the rated draw and still clean up the power from the wall socket, a poor power supply is just over rated and can not meet its draw ratings with out burning up and/or it does not give clean even power.
The circuitry and parts used in a power supply makes all the difference IMO.
I live in an old house in florida where nasty storms hit all of the time and the power always fluctuates, this has a direct bearing on the power supply, good ones will keep the power even, poor ones will jump up and down.
again I rant, sorry |
|
| Back to top |
|
|
Copper
Black Belt 5th Degree
Joined: 14 Jul 2003
Posts: 8613
Location: Midlands UK
|
| Posted: Sun Aug 22, 2004 1:14 am Post subject: |
|
|
| kltsin wrote: | Hmm fans...
Cpu, case and chipset fans 99.001% (I made that number up, but its realistic! ) of the time are +12v.
What you should know about having a small or cheap power supply is that when a system powers on those motors draw 3 times more than they actually use.
In fact anything with a motor has a huge power spike at initial startup, although it doesnt take much to move a fan they do draw a huge amount of amps at boot. Once a fan or motor is spinning the amps drop immensly.
But overall dont read too much into any of this.
Most power good supplies and even some cheap ones can power more than they are rated for.
A good company can sell a power supply that can exceed the rated draw and still clean up the power from the wall socket, a poor power supply is just over rated and can not meet its draw ratings with out burning up and/or it does not give clean even power.
The circuitry and parts used in a power supply makes all the difference IMO.
I live in an old house in florida where nasty storms hit all of the time and the power always fluctuates, this has a direct bearing on the power supply, good ones will keep the power even, poor ones will jump up and down.
again I rant, sorry |
your correct , in what you say. an item in our pc which is often over looked
_________________
"Only two thing are infinite, the universe and human stupidity,and Im not sure about the former." Albert Einstein (1879 - 1955) |
|
| Back to top |
|
|
kltsin
Black Belt 2nd Degree
Joined: 29 Jun 2004
Posts: 2792
Location: St. Augustine, Fl
|
| Posted: Sun Aug 22, 2004 1:31 am Post subject: |
|
|
TY coppershirt...
I did leave out the many other details but thats why I wrote a web page about it.
Most systems would be fine with a good 325 watt power supply, its the graphics cards that are tricky since they can draw a huge amount of power or very little depending on the card in question. |
|
| Back to top |
|
|
J.C.GARCIA
Black Belt 3rd Degree
Joined: 22 Aug 2001
Posts: 3707
Location: Great Beer Zone
|
| Posted: Sun Aug 22, 2004 6:33 am Post subject: |
|
|
i know that the wattage was important but i thought that more important was the amperage on each rail
_________________
p4 2.4b 533mhz fsb
epox 4bea2
768mb ddr pc2100
radeon 7000 64mb w/tv out
120gb seagate hard drive 7200rpm
40gb seagate hard drive 5400rpm
live 1024
dvdrw lg gsa 4040b
cdrw btc 48x16x48x
xp home |
|
| Back to top |
|
|
Twisty
Black Belt 1st Degree
Joined: 02 Mar 2001
Posts: 1904
Location: UK
|
| Posted: Sun Aug 22, 2004 1:12 pm Post subject: |
|
|
the power is the summation of the current x voltage on each rail, but the latter is a better indication of a good power supply because it allows less scope for the manufactures to bodge the values and you can also judge if the power is there where you need it (i.e on the 12V rail not the 5V rail)
_________________
- Webster - |
|
| Back to top |
|
|
J.C.GARCIA
Black Belt 3rd Degree
Joined: 22 Aug 2001
Posts: 3707
Location: Great Beer Zone
|
| Posted: Sun Aug 22, 2004 1:15 pm Post subject: |
|
|
so then the more amperage , current , you have on the 12v rail the better . i suppose this is what you mean
_________________
p4 2.4b 533mhz fsb
epox 4bea2
768mb ddr pc2100
radeon 7000 64mb w/tv out
120gb seagate hard drive 7200rpm
40gb seagate hard drive 5400rpm
live 1024
dvdrw lg gsa 4040b
cdrw btc 48x16x48x
xp home |
|
| Back to top |
|
|
kltsin
Black Belt 2nd Degree
Joined: 29 Jun 2004
Posts: 2792
Location: St. Augustine, Fl
|
| Posted: Sun Aug 22, 2004 8:14 pm Post subject: |
|
|
| J.C.GARCIA wrote: | | i know that the wattage was important but i thought that more important was the amperage on each rail |
Yes you are correct, I believe that was stated by the others and didnt want to repeat that.
The generalisation of a good 325 watt power supply is just that a generalisation, I was more leaning to the power supply quality than output.
| J.C.GARCIA wrote: | | so then the more amperage , current , you have on the 12v rail the better. i suppose this is what you mean |
I believe webster was giving that as an example of what your system requires.
The begining of this post does show how you can figure it out simply but its not very accurate since it doesnt pertain to specific values and what amounts you need per rail
I have a web page that has a chart, although its not complete its has a printable chart and other tidbits.
http://www.angelfire.com/ex/kltsin/psu_info.html
I will try and get it updated to have more cpus and graphics cards shortly.
Also I don't know if any one covered this, when you find the total draw of a system you may want to multiply that by .15 and add it to the minimum required wattage for upgrading purposes |
|
| Back to top |
|
|
derylle
Brown Belt
Joined: 29 Jul 2004
Posts: 331
Location: Illinois
|
| Posted: Fri Sep 10, 2004 12:25 am Post subject: |
|
|
here the #1 website on how to determine what wattage u need: check it out.
http://pcpowercooling.com/products/power_supplies/selector/index.htm
and then check out the nice psu they have, the turbo cool is the model that you should be looking for.
http://pcpowercooling.com/home.htm good luck.
look for
braided cables, high wattage 425w and above, numeroud inputs and are very silent.
_________________
Amd64 3500+ @2.2Ghz
Corsair XMS 1024 Xlpt(2*512)
Ati 9600Xt
Asus A8V Deluxe
Western Digital 160 GB
Maxtor 250 GB
Turbo Cool 425w PSU
Plextor 708A
Sony Dru 530A |
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
|
|
