stock clocked lightning can in some circumstances draw almost 400W of power
Merry Chrsitmas!
I swear I knew you'd come with the tweaktown numbers, I never trusted this website or linked a single link from it so I didn't include it in my reviews database.
And in case you can't see, that's "total system wattage" from the legitreviews" with "furmark" bench, which there's nobody on earth runs furmark 24/7. And again, with these results, considering you are running 2 of the cards, you shouldn't exceed 750W running furmark 24/7.
Same story for the Maximum test by techpowerup;
Maximum: Furmark Stability Test at 1280x1024, 0xAA. This results in a very high non-game power consumption that can typically be reached only with stress testing applications
From the Peak test, which is the maximum load that any average user can experience with the MSI lightening, the card draw 233W, close to the guru3d test which scored 203W throwing a hefty stressing game.
OCING? OCing will add around 80W at best results, giving a card total power of 300W, so 2 of it in CF mode we're talking about 600W, adding 160-180W to an OCed i7 system with some fans so we're talking about a 750W and that's of course in case you're running the PC @ load 24/7.
Fortunately HARDOCP tested the card when OCed at full load and reported the Total System wattage;
A 558W at full load with an OCed power hungry i7 930 and OCed 1190 MHz HD 7970.