power supplies

[jdavis]

I'm building a new AMD system, and considering using 2 power supplies simultaneously. I have a 300W no name PS that came bundled with my Enlight 7327, and the power supply that came with my Compuke computer I bought more than 4 years ago. Am I crazy for thinking that I should/could run all the drives/fans in a modded 7327 (maybe as many as 4 fans) off the old PS, and just the MB off the new PS? More importantly, how do you wire a seperate PS to stay on continuously? Obviously I wouldn't be using the old one to power the MB at all. I probably would mount the old PS to the top of the case (another whole set of complications- any suggestions?). I have a lot of experience as a residential electrician, and no fear of splicing/connecting/whatever to get the job done. Anyone else tried this? Any advice???

 

[mechBgon]

You could fill every available drive bay in a 7237 and still run the system off a 300W power supply, as long as it is an AMD-approved model. The fans are not going to be too big of an issue. Typical 80mm case fans only consume 2W each. Check with AMD's list of approved power supplies, if you need a new one.

 

[jdavis]

Problem is, I'm sure it's not an AMD approved PS. I want to be able to push a cheap TBird as high as it can go, and not worry about the PS as my limiting factor. Mainly, I'm looking for info about how to wire AT and ATX PSs so that they work even if not connected to a MB.

WTHell- Here is my plan. I have an Enlight 7327 case, with a 300W PS. I am tenatively planning to mod the case so that the PS fan and the extra fan space below are exhausting, with a new hole below the lower exhaust fan for an intake fan, to be ducted directly onto a FOP 32-1 HS. The front intake fan will (probably) be a Panaflo 90mm fan (to try to balance things fairly well, but possibly have slight positive pressure). I have already modified the bezel enough to clear up enough air flow.

Since I don't have an AMD approved PS, I was thinking of carrying over my old PS to power all these fans and my drives. Am I crazy, or does this sound like a decent idea???

 

[mechBgon]

I think the power supplies that get AMD's approval don't get it for wattage, but for the quality of the wattage, if that makes sense. You could use an AT power supply to power all the drives and fans from its harness, leaving the ATX power supply with just the motherboard itself. An AT power supply will power up and down using its switch, whereas an ATX is controlled by the motherboard.

If you did want a bit more power, the Antec 303X and Enermaxes are a couple of popular ones. The Antec is a 300W, and they now have a 404X 400W model. The Enermax comes in a 330W "whisper" model and 350W non-whisper that is also very quiet by my reckoning (I have the 350W). The Enermax also features two fans with thermal regulation, which is a nice fail-safe measure.

Hope that is some help.

edit: you know, as I think about it, it does seem very accident-prone to run one AT and one ATX like that. Turn off the AT that powers the fans and drives while the motherboard is running... yeeps. I don't want to imagine what would happen. :Q

 

[hagbard]

Learn from my experience, go with the Enermax and forget about Antec.

...hagbard

 

[kponds]

You do not need to upgrade the power supply just because your adding a few fans. At the most, you be putting another 6 watt load on the +12V supply so you'll need another .5 amps of power for this out of the supply. I don't know about the Enermax unit, but I have a spare 250 watt Enlight around here that puts out 10 amps on the +12 volts line. In other words, you adding 6 watts of load to the section of the the supply that provides 120 watts of power or 5% of the total.

The beauty of the Enermax is not the wattage rating but the regulation of the supply. From an overclockers standpoint, we want the cleanest, most regulated power we can get - particularly to the CPU. The real benefit of the Enermax is its ability to maintain a constant (nonvarying) voltage with all the devices in the system turing on and off. Quite simply the cheaper power supplies do not provide the regulation of the Enermax units and when your CPU is clocked on the edge and all of a sudden your hard drive and a CDROM drive start spinning, the sudden load is something a cheap power supply can't handle without a slite voltage drop across all the supply voltages. This momentary dip in voltage is passed thru the motherboard and to the CPU and whammo, you got lockup. Since the fans will be running constantly (i.e. no start up surge) and they are a relatively monor load, they will not contribute significantly to the regulation issue with the supply.

Do not take this to mean I do not endorse the use of the Enermax supply, I strongly do. But not for the reasons your mentioning (adding a few fans).

 

[Phunktion]

LOL Hagbard.. definitely the quality of the PSU counts as much as the quality of it's warranty.. you've got a good point there..

 

[MortaniuS]

my powerman 300 couldnt handle my 1000mhz oc'ed to 1200 with 16 fans, had to upgrade to a enermax 430 watt.

 

[kw3i]

wtf 16 fans, can you tell us what you have all those things blowing on

 

[GasX]

Is one of them a ceiling fan?