Power Atx y cables

[Silverthorne]

I found a place on the web that sells these y cables so I bought one set of 20 pin atx cables and one P4 12v cable (they screwed up the order and I didn't get the P4 cable). I hooked the atx cable up since I had two motherboards that didn't need the P4 12v cable and booted one of the machines which in turn started the other. I now have 2 motherboards running off 1 power supply. This is a great way to lower that $140 electrical bill. I'm going to order more once they RMA the proper cable back.

One thing to note is that the motherboard were exactly the same but I see no reason why it wouldn't work with different boards.

 

[amdxborg]

Cool! Thanx Silverthorne!

 

[GLeeM]

I've read about these. What a great idea!

Silverthorne, please let us know how this project works out and how much electricity it saves. This would be valuable information to TA member!

Maybe a little tutorial?

Thanks

 

[kmmatney]

I had no idea you could do that! I have a few dead power supplies - I'll see if I can cut off the ATX connector and splice it into a good PSU.

 

[Silverthorne]

Originally posted by: kmmatney
I had no idea you could do that! I have a few dead power supplies - I'll see if I can cut off the ATX connector and splice it into a good PSU.

Spliceing it may be a little tough as you have to do all 20 of them, that's why I was so happy to find this company that made them.

Seven hours later and both computers are still running. My last electrical bill was over $190 but that was with the dehumidifier running, that last bill is what made me try these cables out.

I'll try to let everyone know how this works out, if I get a chance and see if I have other mobo's that don't need p4 12v connectors I'll try it out and see if I can get them to boot.

 

[amdxborg]

If you wanna make your own ATX Y Cable, then this and this and this is what you wanna know...

 

[amdxborg]

Oh and also a cool idea to get rid of some psu heat in the 1st link...

 

[Silverthorne]

Just a little update on what I have done. I now have 10 computers running on 5 power supplies, all boot fine without any problems and most are not the same motherboards so mixing them up does not matter. Give me a month and I will let you know what my power bill looks like.

 

[lobadobadingdong]

a good idea for a crack rack, even quality psu's only have effeciency ratings of ~65-70%

 

[GLeeM]

Thanks Silverthorne!

This is valuable info

 

[BofRA]

Thanks for the Info. Any ideas on what size PSU per cruncher set? I assume if you are overclocking this wouldn't be a good idea

 

[Silverthorne]

Almost all my psu's are Powmax LP6100c's and are 300 W and yes I have machines that are oc'd. Most machines are amd xp's ranging from xp 2000 to xp 3000 and some p4 2.6 and 2.5 celerons, also some p4 2.8e's. All are running stable, I just want to see my power bill go lower. :shocked:

 

[vss1980]

My only query is what about signals that are sent back from the motherboard to the PSU. I mean, if one motherboard shuts down normally, wouldn't it send (or try to send) the signal to the PSU. Will this turn off both boards, leave one on as you would hope, or worse still cause real electronic damage as the 2 boards will have differing signal levels on that pin and may not like that?

What about the other pins on the ATX supply (like power good, etc.)? Just a thought.

 

[Silverthorne]

These are pure crunchers and do not get shut done and they are on some serious battery backup. I would go and test your question about shutting one down but if I shut one down then the other has to go down to restart both. This explains about the wiring and signals.

 

[lobadobadingdong]

green is power on, and if memory serves me right it's pin 14

grey is power good, and should be pin 8, as long as only one machine is connected to power on, then when that mobo is turned on it should turn on both boards, the power good line should be connected to both motherboards to help prevent the psu doesn't damage either boards in the event of a failure by shutting itself down.

 

[SinfulWeeper]

I wonder if you get a quality PSU with some decent 12v amperage if you can run three or four motherboards off one PSU

 

[nbarb99]

I remember a link someone posted a while back to a post where a guy had 5 motherboards off one PSU. The PSU wires started to melt

 

[ElisaH]

gracias

 

[SinfulWeeper]

I dont think enough amperage can go through them to do such... unless he mis-wired.

 

[3chordcharlie]

How much savings would there be - like how much overhead would be saved by ruing two PCs from one PSU? The efficiency doens't matter; wouldn't it be approximately the same efficiency whether it's running @125W total output or 250W total outpu?

 

[imported_whatever]

i remember seeing a review of some psu recently that get ~60% at low draw and ~80% at high draw, so it is letting it do high draw and therefor high efficiency.

 

[3chordcharlie]

Originally posted by: whatever
i remember seeing a review of some psu recently that get ~60% at low draw and ~80% at high draw, so it is letting it do high draw and therefor high efficiency.

Oh I'm sure it makes some difference to have them running at an optimal level (I'm even willing to bet the hit peak efficiency at 70-80% of maximum output). I'm just wondering how much real cost savings would be realized. in the end.