Originally Posted by rpg711
He plans on going for 670 sli or 770 sli, the latter being exactly that 680 sli that you mentioned. 650w is cutting things a little bit close, no? It'll be something like 400-450w draw max from gfx(500-550 depending on OC for 770s), and then possibly 120-150w from the cpu/mobo.
It wouldn't be cutting it close with a good quality-made 650W PSU:
With two GTX 670s under full load in their system, their PSU pulled 433W from their wall outlet. Their CPU was idling, so I have to add about 150W for a 3770K under full load overclocked to 5 GHz. So with the 3770K at 5 GHz and under full load and with the GTX 670s under full load at the same time, the PSU would then be pulling 583W from the wall outlet. So if the PSU is 90% efficient while pulling 583W from the wall outlet, then the computer is pulling 524W from the PSU. The gaming power draw will be at around 400-500W. This is easy for a good quality-made 650W PSU.
With two GTX 680s under full load in their system, their PSU pulled 473W from the wall outlet. After doing the same kind of calculations as above, the final wattage (before listing the gaming power draw) comes out to be 560W. The gaming power draw would be at around 450-525W. This is still easy for a good quality-made 650W PSU.
With two GTX 770s under full load in their system, their PSU pulled 505W from the wall outlet. Again, after doing the same calculations as above, the final wattage (before listing the gaming power draw) comes out to be 589W. The gaming power draw will be at around 475-550W to maybe 575W. Again, this is still easy for a good quality-made 650W PSU.
The calculations before listing the gaming power draws above are unrealistically high because I'm saying that the CPU and the video cards are completely maxed out to their limits simultaneously. That's something that practically never happens which is why I mentioned the estimated gaming power draw.
You see, a good quality-made 650W PSU can easily deliver 650W 24/7 if it's ever needed, so even having 575W pulled from such a PSU is not a big deal, especially since it could only happen while gaming. Of course, the plan is two GTX 670s because he already got one for free (for Christmas), so the power draw will be 400-500W while gaming.
Edited by TwoCables - 6/1/13 at 10:49pm