2 PSUs on one system.

[Coswar]

Thought I start a new thread about this question- because it's different than my last one. I have 2 300w power supplies from Dell prebuilts, and I want to power an old Core2Duo with a HD 6950. Could I use the second PSu to power the 6970? And what is the method to power on the second power supply? Do I need to join wires between the 2 PSUs or, just jump the second one?(I believe this is done by connecting the green wire to one of the black ones??) Thanks

[Cacao]

I don't think that would work, I doubt the PSUs even have power connectors for the GPU?

[Oshino Shinobu]

You could jump one, but it's best to use something like this. That way both PSUs will turn on with the power button. 

 

[Coswar]

I don't think that would work, I doubt the PSUs even have power connectors for the GPU?

I have sata to pcie adapters

[Coswar]

You could jump one, but it's best to use something like this. That way both PSUs will turn on with the power button. 

 

So I plug both of my 24 pins into that? Could I just join the cables to do the same thing? Know which ones I'd have to join?

[xXxYOLOxSWAGxXx_420BlazeIt]

Why cant you just power it with a single power supply? I doubt it uses more than 300 watts.

[Coswar]

Why cant you just power it with a single power supply? I doubt it uses more than 300 watts.

I asked that yesterday, and everyone was of the opinion that 300 was too little for it. Given that the 6970 has a TDP of 250w on its own...

[quan289]

Thought I start a new thread about this question- because it's different than my last one. I have 2 300w power supplies from Dell prebuilts, and I want to power an old Core2Duo with a HD 6950. Could I use the second PSu to power the 6970? And what is the method to power on the second power supply? Do I need to join wires between the 2 PSUs or, just jump the second one?(I believe this is done by connecting the green wire to one of the black ones??) Thanks

 

You need to pay attention to the design of the PSU if you are doing dual PSU setup. A group-regulated PSU will have voltage stability issues cause by imbalances load on the 12v and 5/3.3v with such a setup - a type of PSU that your two Dell PSUs are.

 

Get a proper single PSU for your system.

[Coswar]

You need to pay attention to the design of the PSU if you are doing dual PSU setup. A group-regulated PSU will have voltage stability issues cause by imbalances load on the 12v and 5/3.3v with such a setup - a type of PSU that your two Dell PSUs are.

 

Get a proper single PSU for your system.

Not worth the money- what if I don't connect them, and just jump the one for the GPU everytime I turn it on? I could easily put a switch on the jump cable

[Coswar]

Not worth the money- what if I don't connect them, and just jump the one for the GPU everytime I turn it on? I could easily put a switch on the jump cable

Anyone know if this is possible?

[FizzyFantom]

Anyone know if this is possible?

Absolutely, just make sure its a click on and off type switch rather than a push to make (get one like a light switch or the switch on the back of a PSU). I removed the two pins from an old PSU and added a switch to make a bench PSU.

[Coswar]

Absolutely, just make sure its a click on and off type switch rather than a push to make (get one like a light switch or the switch on the back of a PSU). I removed the two pins from an old PSU and added a switch to make a bench PSU.

Great! And just to ask, which black cable should I use- or does it matter? I know I connect that to the green.

[FizzyFantom]

Great! And just to ask, which black cable should I use- or does it matter? I know I connect that to the green.

It doesn't matter which black cable you use as they're all ground, just make sure you use the correct power sense wire:

http://corbietech.co.uk/wp-content/uploads/2013/05/ATX_24pin001a1-300x259.png

[Coswar]

It doesn't matter which black cable you use as they're all ground, just make sure you use the correct power sense wire:

http://corbietech.co.uk/wp-content/uploads/2013/05/ATX_24pin001a1-300x259.png

Thank you

[quan289]

Not worth the money- what if I don't connect them, and just jump the one for the GPU everytime I turn it on? I could easily put a switch on the jump cable

 

How you plan on turning on the second GPU doesn't change the fact that your system will be running in a crossload scenario of which there is little to no loads on the 3.3v/5v (depending on how you set it up) and a high +12v load.

You are basically doing something similar to the Crossload 2 test here. http://www.techpowerup.com/reviews/Antec/VP550F/5.html

With little load on the 3.3/5v and a high load on the 12v, the voltage on the +12v drop below 11.4v mark and violated ATX specification.

 

Also, here's a discussions on the effects of voltage regulations and ripples have in your system: http://www.jonnyguru.com/forums/showthread.php?t=11297

[Coswar]

How you plan on turning on the second GPU doesn't change the fact that your system will be running in a crossload scenario of which there is little to no loads on the 3.3v/5v (depending on how you set it up) and a high +12v load.

You are basically doing something similar to the Crossload 2 test here. http://www.techpowerup.com/reviews/Antec/VP550F/5.html

With little load on the 3.3/5v and a high load on the 12v, the voltage on the +12v drop below 11.4v mark and violated ATX specification.

 

Also, here's a discussions on the effects of voltage regulations and ripples have in your system: http://www.jonnyguru.com/forums/showthread.php?t=11297

So what you are saying is that the additional PSU would be unstable as it only has load on the sata cables?

[Coswar]

 

Also, here's a discussions on the effects of voltage regulations and ripples have in your system: http://www.jonnyguru.com/forums/showthread.php?t=11297

So from reading this I also understand that the life of my parts may be shortened- but given that all the parts are old( and the 6970 has heating issues) this doesn't worry me. I'd rather have them work for another 6 months than let them sit there- because I lack the funds to spend on a new PSU

[toilet-handle]

didnt newegg have the cx500m for 29.99? thats too much money?

[Coswar]

didnt newegg have the cx500m for 29.99? thats too much money?

Any money is- this is just for fun.