P/S recommendation

I have a 400W power supply.  I am going to add fans and another HD to my system and was wonder what other people thought about this.  I do not know if a 400W P/S can handdle the load or not.  This will be my configuration

CD burner
Fan controller w/5 fans
3 HD
I also have to take into consideration my fan for CPU and Memory
i just don't want to put the stuff in and close it all up and have it spudder.  I am in no means worried about getting another P/S but i do not want to if i do not have to.
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400W Should be OK for this.  If you are Really Worried about it, then get a 450W.  
Side note: the bigger the PSU, the less strain it has to take on bootup, when everything wants juice at the same time.
See this link if helps you

Good luck.
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Ignacio Soler GarciaSolution Architech & Technical LeadCommented:
Well, I want to put my own 5 cents about this (i'm not native English speaker so expect languaje mistakes).

I don't know why on computers the PS aren't considered like on all the other stuff that needs PS. Every PS has to fit to the energy needed, less and it will burn and more and you're wasting money, energy and noise. So, the choice has to be done making some calculations, you can't  make a rough guess at its power, so let's go:

The easy thing about this is that the power that you need is simply the sum of all the individual power consumption of every component inside your PC. The hard thing is that you can't get those powers needs easily (again, I don't know why. In every bulb, hi-fi, TV, etc ... is indicated the power needed) so let's look at some general points:

a) Hard disk:   as seen on the web specs of a seagate 20GB ST320410A it has a power consumption (from now P) of 7.5
                       watts. A 7500 rpm ST380011A 120GB has a P of 12.5 watts.
b) Mainboard: i haven't been able to get any information about the P of a motherboard, but looking at some points here and
                       there I can stimate the P in 20W
c) CPU: the P of a Pentium 4 3.06 GHz is 81.8 watts, a Palomino Athlon XP 2000+ has a P of 70.5 watts.
d) CD-Recorder: a HP recorder 8000i has a P of 15.8 W
e) CD-Reader: a Mitsumi CRMC-FX320S has a power consumption of 5.8 watts.
f)  Fans: each fan has a diferent P but I think that they use to have it written on the external protective part. They go from 1W to 10W. A tipical CPU fan may have a P of 2 watts.
g) VGA: a Nvidia GeForce 4 Ti 4600 has a P of 29.80 watts.

So let's do a sample:

A tipical system with all those things can have:
4 x ST380011A (120 Gb) = 4 x 12.5 = 50    W
1 x Mainboard                 = 1 x 20    = 20    W
1 x Athlon XP 2000+       = 1 x 70.5 = 70.5 W
1 x CDR                           = 1 x 15.8 = 15.8 W
1 x CD                             = 1 x 5.8   =   5.8 W
2 x CPU like Fan              = 2 x 2      =   4    W
1 x VGA                           = 1 x 29.8 = 29.8  W

Total power needed                         = 195.9 W

Now you must add all the PCI powers (let me tell you that the power needed by a PCI LAN card or an audio card will be less than 10W for sure, more likely like 5W). So lets put 20 W more to be safe.

Add keyboard and mouse and anything else that you have on your USB, serial or paralel ports and you have about 20W more (must be measured depending what devices you have, of course).

So, at the end we have a P of 195.9 + 40 = 236 W more or less. To be safe is good to take allways a 20% more power to afford the peaks that can be on the system so 236 + 20% = 282W. More or less the power capacity of all the PS on the market (300W). That's why the sell this power as the standar.

You, with an enhanced PS can forgett power problems forever (while you don't put a bulb on the USB port), so be happy and put 2 hard disks more without trouble.

All the data has been taken from the respective webs, from the specs documents.

To me, the data on http://www.distortionwave.com/power.html looks like mere rough guess, that's why i wrote this.

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Here is my two cents worth, check out these two links!!! Good luck, Jerry

Just to put my bits worth in. First off I agree with the others that you should be ok using your current PSU, but it's important to remember that the quoted wattage is not as important as the quality of the PSU. Having a rating of 400W is one thing, but maintaining/dealing with the actually much lower individual loads and keeping your system stable is another. There are a lot of factors you need to consider/remember when looking at a PSU:

(In no particular order and by no means the full list)

The strain on the PSU when you start your system is huge when compared to using it; for example a hard drive can draw 8-10W when running, but 20W+ when spinning up. It's a similar situation with putting your machine in standby mode, the PSU has to deal with providing the low levels of constant power and then the rush as you start it up again.

You have to look at the amount of power provided on each of the rails, therefore you have to go through your devices and see what uses what and from that work out your requirements. You see, it may offer a stable 400W, but how is that split up between the 12V, 5V rails and so on.

How is the cooling on the PSU? It will run quite hot, so having a decent set of fans built in helps (especially if your ambient temp. is quite hot), as does having large, good quailty and adjustable fans, not least because of the noise.

All the other bits such as efficiency, peak inrush current, PFC, the metal it's made from, the minimum power levels, safety features, is your local power supply stable and so on (and on).

I know a lot of this has already been said, either directly or through some good links, but I just wanted to personally emphasise that the wattage is not as important as how it's split between the devices and how stable the whole lot is. Even though I know it's excessive I never get within 100W of the (total) max wattage of my PSU's (and to be honest, without trying and all other factors being equal, neither do most people), so it's sort of unimportant. Personally I use (and recommend) Antec or Enermax PSU's (though there are lots of other good ones) as often you don't have to work it all out, since their PSU's are often decent, therefore you can afford to be a bit off on certain factors. Having a stable system is worth the extra cost of having what seems to be a vastly over the top PSU (plus you can reuse it later on on a new system as it's still up to the job).


PS: If you can list the name/model of your PSU, I, or I'm sure someone else, will be happy to give you their opinion on it.    
buckeyes33Author Commented:
what I am seeing from several of the website is that I need to make sure that I have enough +12V amps.  The 400 W is plenty of power, but the really question is can it handle the amps?  This is what i am getting from the websites. I am correct?
thanks for the help
Ignacio Soler GarciaSolution Architech & Technical LeadCommented:
Hello again,

power and amps are dependant things. Power = voltage x amps. Knowing that voltage is always the same, what you need is to know the amps that the device will use. If you have a power of 400W the part of this power gived to the 12V output should be 280W and the 5V output should be 120W (more or less, this is the proportional part).

So, if you have 280W with 12V you can give as much as 23 amps.

It's nice to remember the old electronic school's days ;)

As I said before, my opinion is that you can forget this matter with the PSU that you have and invest the time looking for a really breaking hard disk.

See you!

FWIW... ratings are just ratings.  Cheap PS's might be able to put out 400 watts but not maintain the voltage.
Also, why would anyone want to listen to FIVE fans + a CPU fan + a PS fan?  Where do you live? Hell?
buckeyes33Author Commented:
doing a little searching and some work in excel i have came up with this

      Amps at Voltage                  
part                      12V       5V       3.3 V      watts used
seagate hard drive      2.5      0.8            34
western digital      1.8      0.5            24.1
maxtor HD      1.05      0.4            14.6
case fan one      0.14                  1.68
case fan two      0.14                  1.68
case fan three      0.25                  3
case fan four      0.25                  3
case fan five      0.25                  3
cd rw                      1.5      1.5            25.5
cd rom                        1                  12
memory fan       0.11                  1.32
CPU fan                       0.5                  6
CPU Athon XP           8                  96
video card                  3      9.9
memory  1            3            15
memory 2                            3            15
mouse                             0.5            2.5
keyboard                            0.25            1.25
usb device 1            0.25            1.25
motherboard      0.5      3.5      1.5      28.45
pci controller card            1            5
floppy disk            0.8            4
usb device 2            0.25            1.25
total amps      18.99      15.75      4.5      321.48 total watts
I understand that all these figures are on the high end of power consumtion.

listening to that many fans is not bad.  I can stand to listen to the noise if my equiment last two more years.
buckeyes33Author Commented:
that did not turn out like it was supposed to
buckeyes33Author Commented:
ok the max amps on +12V is 18 for my power supply.  As you can see(actually it is hard to see) that the max pull of amps from all the computer componets is 18.99 amps.  This is above the max of the power supply.  What can happen if to many amps are pulled?  I realize it is probably has something like a breaker system.  Also, how much does it effect the power supply?  In this I mean having about half or more being pulled all the time can not be good on the P/S in my eyes.  Would it drastically change how long the P/S will last?
It will probably take it for awhile, but that much strain over a long time is Not A Good Thing.
Cooling is the key as you already know. High amperage may generate enough heat that it exceeds the cooling design of the power supply thus failure either abrupt or premature. The cooling capacity of the power supply depends on the supplies fans and heatsinks(mass). A heavy power supply with multiple fans is one indicator of a well constructed unit. Your calculations are well done. Keep in mind that other than at start up you will not draw 18.99 amps...as long as your power supply can handle brief peaks in current draw you should be OK. My 12V specs are 20 amps max and 24 amps peak...your power supply most likely has a similar rating. As the power supply ages a well constructed one will stay within spec longer. Dirt and dust are the enemies...intake filters are worth the cost of airflow restriction. T
buckeyes33Author Commented:
What happens to other hardware when a P/S goes out?
Depends on how it dies. Usually nothing happens to other hardware, but once in a great while ( rare ) it could send a spike thru the system, which could fry something.
Like coral47 says most of the time all you need to replace is the power supply. But a direct or very near hit of lighting can pass the power supply and also take out other componants such as the mother board. That is why it is realy important to have a good surge protector. One that opens up and will not let current through after it take a large spike. Good Luck, Jerry
Ignacio Soler GarciaSolution Architech & Technical LeadCommented:
Mmmmm, just wait a moment. There are more things to have in mind than what you are saying.Y ou can have several possibilities:

a) You have only a small overcurrent: that won't hurt for sure. Maybe the PSU works at 2º or 3º more but nothing else would happen. When a dessigner writes limits they are giving at least a 10% tolerance so you will be inside the tolerance. (Remember overcloking basics?)

b) You have a big overcurrent but not big enought to burn everythin, like a 25 - 40% more current for example. A swiched power supply will drop the voltage as the current goes up, so what you will have is a system that hangs. If you're smart enought to find what is happening you won't get the PSU burned. Of course, if you have it sometime with the overcurrent it will blow up finally.

c) You have a REALLY BIG overcurrent. Not like a lighting because it has nothing to do with overcurrents. This is a grow of the input voltage not a current requirement too high. You have just a too big current requirement. Here you can also have two possibilities, first the PSU can burn and then maybe something  can get damaged inside the computer. Also, all those switched PSU have shotcircuit protection. If you do a shortcircuit the PSU stops working before being damaged. So its possible that the PSU thinks that you have done a shortcircuit and will stop working until you power it again.

As you can see it's hard to damage a PSU (they're supossed to be robust!). The worst case is when you have only a, say 20%, overcurrent, too high for the tolerance, and not high enough to drop voltage. Then you can have a overheat with time that will damage the PSU over the time. You will notice this because the PSU will be really hot.
<<I can stand to listen to the noise if my equiment last two more years.>>
I really doubt 5 fans will help at all...might even hurt by kicking up the dust...but even if they do, how much will the system be worth in those last couple years?  I bet it isn't even worth the extra electric bill not to mention the cost of the fans and the annoyance of the noise.
Also, depending on the size of your old hd's it might be cheaper to put more $ into a larger new one rather than upgrading your ps.
buckeyes33Author Commented:
thanks to eveyone who has posted. I have learned a lot of information. I divided the points up to how many times you posted.  Thanks again
Thank you, Jerry
Thank you much.    : )
Thank you :o)
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