Sapphire R9 280X Crossfire Power Usage

[Release The Kraken]

I've had my current PC since last May and I had the choice of buying up better parts to build a new one, but I'd like to avoid that if possible and just add another card to my system. What worries me is the power supply not being enough to handle the system. I've tried every PSU Calculator I could find and I keep getting different results. Some people and PSU calculators say that even 700W would work fine. Some people and PSU calculators will say that I would need a minimum of 950W-1000W. I would really appreciate some solid answers before I proceed.

My system -

AMD FX-4300 3.8GHz (OC'd to 4.20GHz)
8GB DDR3 Memory (2x4)
Sapphire R9 280x (http://www.newegg.com/Product/Product.aspx?Item=9SIA2E116M0843)
750W PSU
7,200 RPM HDD (x2)
5 USB Devices
2 case fans
1 DVD/CD Combo drive

 

[_Vass]

750w (if it's a quality one) is enough for sure

 

[siddharthmukul007]

a good 750w is good enough

 

[Release The Kraken]

750w (if it's a quality one) is enough for sure

750 Watts - Corsair CX750 750W 80 PLUS BRONZE Certified Active PFC Power Supply
I had it built for me by Cyberpower and that's the exact power supply that was placed in the machine.

 

[Release The Kraken]

a good 750w is good enough

750 Watts - Corsair CX750 750W 80 PLUS BRONZE Certified Active PFC Power Supply
I can differentiate between good and bad GPU's and CPU's but I'm not so sure when it comes to power supplies.

 

[_Vass]

a good 750w is good enough

750 Watts - Corsair CX750 750W 80 PLUS BRONZE Certified Active PFC Power Supply
I can differentiate between good and bad GPU's and CPU's but I'm not so sure when it comes to power supplies.

the cx series are low end but in theory more than capable of powering 2 280x cards. how many A on the 12v rail?

 

[Release The Kraken]

the cx series are low end but in theory more than capable of powering 2 280x cards. how many A on the 12v rail?.

I'm not exactly sure what you mean. The power supply isn't modular and I just grabbed one of the 6+2 PCI-E connectors.

 

[siddharthmukul007]

the corsair cx750 can provide 744w on the 12v rail....the sapphire r9 280x consumes around 350w. so 2 of them would at the most take almost 700w.

i would not recommend using the cx750.

get this instead:

http://pcpartpicker.com/part/corsair-power-supply-tx850m
or
http://pcpartpicker.com/part/xfx-power-supply-p1850snlb9

 

[_Vass]

the corsair cx750 can provide 744w on the 12v rail....the sapphire r9 280x consumes around 350w. so 2 of them would at the most take almost 700w.

i would not recommend using the cx750.

get this instead:

http://pcpartpicker.com/part/corsair-power-supply-tx850m
or
http://pcpartpicker.com/part/xfx-power-supply-p1850snlb9

350w ea?! pls read this http://www.tomshardware.com/reviews/radeon-r9-280x-r9-270x-r7-260x,3635-18.html not anywhere close to 350 w. 750w should be more than enough to run 2 280x

 

[siddharthmukul007]

the corsair cx750 can provide 744w on the 12v rail....the sapphire r9 280x consumes around 350w. so 2 of them would at the most take almost 700w.

i would not recommend using the cx750.

get this instead:

http://pcpartpicker.com/part/corsair-power-supply-tx850m
or
http://pcpartpicker.com/part/xfx-power-supply-p1850snlb9

350w ea?! pls read this http://www.tomshardware.com/reviews/radeon-r9-280x-r9-270x-r7-260x,3635-18.html not anywhere close to 350 w. 750w should be more than enough to run 2 280x

power consumption varies from card to card.

http://www.overclockersclub.com/reviews/sapphire_r9_280x_toxic/16.htm

 

[_Vass]

the corsair cx750 can provide 744w on the 12v rail....the sapphire r9 280x consumes around 350w. so 2 of them would at the most take almost 700w.

i would not recommend using the cx750.

get this instead:

http://pcpartpicker.com/part/corsair-power-supply-tx850m
or
http://pcpartpicker.com/part/xfx-power-supply-p1850snlb9

350w ea?! pls read this http://www.tomshardware.com/reviews/radeon-r9-280x-r9-270x-r7-260x,3635-18.html not anywhere close to 350 w. 750w should be more than enough to run 2 280x

power consumption varies from card to card.

http://www.overclockersclub.com/reviews/sapphire_r9_280x_toxic/16.htm

total system w?