would a non external power required gpu work with the cpu´s voltage on the mobo?

Nach671

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Feb 4, 2014
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i´m thinking about buying a sapphire radeon R7 250 1gb gddr5, and, as well as it does not need any external power connector, i suppouse that my psu will be fine but , as i don´t want to have any future issue either, i ask here for advice.
I know the gpu will drain power directly from the pci-e conector but i´ve no idea if it´ll work with the cpu voltage (3.3V/5V) or the 12V rail. Please help me!
This is my rig:
intel core i3 3220
asus p8h77-m pro
8gb kingston ddr3 1333 mhz
LG dvd modisc burner
hitachi 7200rpm 500gb
overtech MA-6500-BTX 500w PSU (non 80 plus certified)
+3.3V: 24A
+5V: 18A
+12V1: 17A
+12V2: 16A
-12V: 0.5A
-5V: 2.5A
 
Solution
The CPU is supplied by the 4 or 8 pin connector that plugs in next to it, that provides 12V power to the CPU, nothing else gets to tap off of this.

The PCI-e slot is fed by the 24 pin motherboard connector, the vast majority of the power that the GPU consumes is from the 12V rail, but it does pull some from the 3.3V and 5V rails. Very few things feed off the 3.3V and 5V rails so they have plenty of capacity for systems these days which is why we only usually worry about 12V rail capacity because both the CPU and the GPU draw most of their power from it.
The CPU is supplied by the 4 or 8 pin connector that plugs in next to it, that provides 12V power to the CPU, nothing else gets to tap off of this.

The PCI-e slot is fed by the 24 pin motherboard connector, the vast majority of the power that the GPU consumes is from the 12V rail, but it does pull some from the 3.3V and 5V rails. Very few things feed off the 3.3V and 5V rails so they have plenty of capacity for systems these days which is why we only usually worry about 12V rail capacity because both the CPU and the GPU draw most of their power from it.
 
Solution

Nach671

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Feb 4, 2014
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thanks, you solved my doubt. But you guys would recommend me to go for a grater psu? keeping in mind my rig´s TDP; or i´m fine with the one i´ve got?
i3 3220- 55w max TDP
R7 250- 65w max TDP
 

Yingda Wang

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Jan 1, 2014
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I would run "fine" But would recommande getting a new one. Generic or crappy brand gpu arent know for reliability, especially if it cant even match the 80% efficiency.
Getting a antec basiq 450w for like 25$ would be a good choice.
 

Nach671

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Feb 4, 2014
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what about a sentey BRP 500w ? would it be enought?
 

Nach671

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Feb 4, 2014
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I´m from Argentina, and there are not so many brands in here as there must be in States, but here is a list of possible psu´s i could buy:
-Sentey Brp 500w
-Topower Nano 500w
-VITSUBA SAN-55-S 550w
-Saikano MASS 500w/650w
-Sentey ERP 550w
please tell me which of these i should get