Adding another gpu

[raulmontiel]

Hi there, im planning to add another gtx 780 to my build (this is entirely for rt purposes, i know corona doesnt support it), but i dont know if my 600watts power supplys will handle both gtx and an i7 5820k.
Any advices? should i upgrade my psu too?

[Bzuco]

Definitelly buy better power supply. One GTX 780 has TDP of 250W, during RT rendering it can eat 220W...it depends also on rendering tasks and how much RT utilize gpu core. You can check gpuz utility during RT rendering.
5820K has 140W TDP. Also check power value in core temp or similar CPU utility during RT.
You can alsou save some watts if you undervolt 5820k and also both gpus. You can save significant amount of  watts during high cpu & gpu usage. For power supply it is better if it is utilized around 50% (highest efficiency) so if all your components eat together cca. 600watts during 100% utilization, then ideal power supply for long power supply life is something around 800+watts 80+ gold certification.

[philippelamoureux]

I run a i7 4790k with a gtx 980 sc on a 330w psu. Like a boss! But don't do like me! :-)

I have absolutely no room for overclocking or add a dvd player or another fan but heh, this is what happens when you want a ultra slim gaming pc. I'm still shocked my machine even work with such low wattage.

[Christa Noel]

there are many websites offers accurate PC power calculation. almost no difference in each website calculation result.
http://powersupplycalculator.net/
http://www.coolermaster.com/power-supply-calculator/
https://www.msi.com/power-supply-calculator

I run a i7 4790k with a gtx 980 sc on a 330w psu

wow! are you sure your PC runs normaly? if yes, definitely you're the boss :)

[raulmontiel]

Thank you, its a very usefull tool, unfortunately i will have to change my psu for another 750w unit :(

[philippelamoureux]

there are many websites offers accurate PC power calculation. almost no difference in each website calculation result.
http://powersupplycalculator.net/
http://www.coolermaster.com/power-supply-calculator/
https://www.msi.com/power-supply-calculator

I run a i7 4790k with a gtx 980 sc on a 330w psu

wow! are you sure your PC runs normaly? if yes, definitely you're the boss :)

Yes. The original pc was an alienware x51 thats comes with a HDD and a GTX 760ti and runs on an external brick psu of 330w. Since I have a limited power budget I had to remove a fan, remove the dvd player, swap the HDD for a SSD and the 760ti for a 980. I cannot upgrade anymore unless they release better gpu with lower consumption. I have no problem running games for hours, even played with my htc vive, etc.