As a perfectionist and owner of a watercooled pc, I feel a need to get rid of the last fan in my system. Not because it's noisy, but because I can. Aquacomputer (http://217.172.178.216/) sells watercooled psu's in Germany for 300 Euro (hence the word "silly" in the topic), and I feel the urge to buy one. They are based on an existing Engelking psu, and I believe the quality is rather high, it's just that for such an expensive thing, the power rating is modest : 250 W. Now this is not peak power, but sustained power, so it's not that low. I'm just worried about the max output of the individual lines, and if they are enough for the next pc which probably has an even more power hungry processor because I'd like it to last longer than just my current pc. So to the experts on how much current is needed on each voltage lines I ask: Are these numbers more than adequate (alas: also good for future), or just adequate (good for now, but not for the next pentium 4 @ 4GHz) ?
Here are the numbers:
3.3 V : max 20 A sustained.
5V : max 21 A sustained.
12 V : max 13 A sustained.
Max combined power output :110W(30A).
Max sustained power output : 250W.

My current system (briefly):
P4 2GHz
Geforce 4200
2 HD's
1 cd writer
network card
soundcard

Thanks in advance for a well argumented answer!

http://firingsquad.gamers.com/guides/power/default.asp read this article it has a guide about calculating the power ratings of all your devices.
having a look at your setup I'd say u'd *just* nudge into the power ratings for most of your devices, one thing that may be possible is to buy a higher rated power supply and mod it so that it is water cooled (I'll let bladerunner do a fill in here)

Thanks for the address. I've been looking for it, and after calculating with their method, it seems I need around 350 watts of power. This seems a lot to me, especially since everything in this site points at much lower powerconsumption. The info provided by firingsquad is very usefull as far as components, but I think just adding up the maximum powerconsumption of all components isn't going to give me the right figure. I did learn though, that p4s get their power from the 12V rail, so that's what I should look at mostly when thinking about future processors. But I still would like some more opinions about this psu from knowing spcr readers/members. Thanks!
O, forgot: I know of projects modding psus to watercooling, and although I do a lot of freaky things with my pc, I'm NOT going to build a watercooler close to 220V myself. I've already learnt that the heatsinks on my psu are live , and replacing it's fan is as far as I will go with it.

Hi...

I've written a number of recent reviews on Overclockers.com that directly measure real (not estimated) power draw. While I agree with some of the power estimates that gamers.com posted, some of mine actually are quite different. My measurements seem to indicate that the requirements for the +12v line are ~75watts, +3.3v ~20watts, +5v ~10watts with 2 hard drives, 2 CDRW's, 3 fans, a Ti4200 vid card and 1 pci card. I'm assuming that you're using a reasonably current Intel chipset based motherboard (845 variant) Some pci cards can draw more power, especially sound cards and devices that have many outside connections.

Another fact that might help you is that the voltage regulator module that Intel specs for use with their chipsets and P4 CPU's can deliver an absolute maximum of 60 amps at default Vcore. This means that the worst condition power requiement for the 12 volt line ONLY RELATED TO THE CPU could be 90watts.

My general recommendation is to look for a very solid 12volt rating as the most important spec when buying a PS. The 3.3v line is the next most important, and then the 5volt rating.

One more thing...most motherboards have a jumper on them allowing you to select whether the USB stuff is powered by the normal 5 volt supply, or the 5volt Stand-By supply. I always choose the normal 5 volt supply because some USB components can draw LOTS of current and can briefly overload the 5vSB rail. This very short overload causes the other voltages to deliver current at a slower rate and may cause a board not to come out of standby properly.