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Combining 12v rails?

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I am still getting all kinds of performance problems in just cause 3. A friend who has a GTX 780, and a PSU that has a single 12 volt rail that provides 80 amps, gets smoother performance. He showed us at work today on his 120hz monitor and it is glorious.

When I built me rig I was an idiot and allowed my inner cheapskate to win. The PSU I purchased (~$100) has 6 12 volt rails, each providing 20 amps. The working theory between my self and a friend is that the GPU is not geting enough amps. The PSU has a total of 5 PCI-E connectors. I assumption is each PCI-E line has its own rail. The GTX 1070 uses an 8 pin and a 6 pin. The GTX 970 uses 2 6 pin connectors. Assuming I can hack together some kind of Y or W cable in order to give the 1070 more amps.

 

PSU:

TOPOWER ZU-1050W 1050W ATX12V v2.2/ EPS12V v2.91 SLI Ready CrossFire Ready Active PFC Power Supply , http://www.newegg.com/Product/Product.aspx?Item=9SIA2J53UC1172

 

Is it worth a shot?

If I had the $ I'd buy a better PSU. Young fabulous and broke.

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Your Topower ZU-1050 is priced at only $100 because of it's 80 plus rating, not modular, and not designed for low volumes or silent fan mode,.. but it does still provide 96A on the +12V output which is plenty for your graphics card and other hardware.

 

The common misconception is that a rail is a part in the power supply that provides power. This is false, a rail is a group of traces on the PSU's main board that are monitored by an OCP circuit.

 

OCP is Over Current Protection, what OCP does is it monitors an output on a power supply,.. Multiple rail : each trace is monitored separately, so if one trace goes over 25A the power supply will shut down. Single rail : all traces are monitored all together, so if the total current going through the +12V outputs goes over say 85A, the power supply will shut down, alternatively, no OCP may be present at all on the +12V rail.

 

So which is better? well , neither has any effect on voltage stability, ripple suppression or efficiency, at least not to a measurable degree.

 

However, there is one difference,.. if you have a short circuit on the +12V and the SCP (short circuit protection) doesn't catch it.

 

On single rail power supply the draw on that one +12V wire and that one +12V trace will climb untill either the combined OCP point is reached, or until something burns, usually something will burn before the combined OCP point is reached.

 

On multi-rail power supply, the current would climb until it hit that rails OCP point, at which point the PSU would shut down to protect itself and your computer.

 

So basically muilti-rail unit will provide you with an extra layer of protection,.. with low-wattage units it doesn't matter. OCP on single rail is useful up to about 40A or thereabouts, which is where most 550W supplies fall. So with 550W and under it's a moot point,.. but 1200W single rail with over 100A OCP will destroy your motherboard damn quick with a short circuit, so there is a danger with single rail units over 1000W.

Edited by Braegnok

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The psu you linked looks to have a combine switch on it like my PSU (also a topower) does.

Have you flipped the switch to see if it changes anything?

Sent from my SM-J700P using Tapatalk

/Me beats self over head with the manual. Will do that.

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The switch on your power supply is for the fan speed,.. irritating or more irritating (turbo).  

 

Some units have an AC input switch for 110-240VAC,.. but your unit has Auto switching circuity for universal AC input. 

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The switch on your power supply is for the fan speed,.. irritating or more irritating (turbo).

 

Some units have an AC input switch for 110-240VAC,.. but your unit has Auto switching circuity for universal AC input.

There is a button and switch. The button is turbo The switch is combine

 

Sent from my SM-J700P using Tapatalk

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Not sure what you mean by "combine switch" you got me confused. :lol:  

 

The ATX12V 1.3V and ATX12V 2.01V switch is different system standards and ATX power supply revisions.  

 

 

   https://www.newegg.com/Product/Product.aspx?Item=9SIA2J53UC1172&cm_re=topower_zu-1050w-_-9SIA2J53UC1172-_-Product

Edited by Braegnok

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My bad thought it was a combine switch. Couldnt get the pic big enough to read it on my cell phone.

 

Topower has made a number of psu that have a switch like that that have "split / combine" 12v rail.

 

Sent from my SM-J700P using Tapatalk

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