ya i agree with you Mitchmd:

so i think a 850W EVGA PSU can only safely run 3 KD Boxes because i plugged a 4th in and the boxes caught on fire …

This may have happened but i tried doing some math before sticking things in holes without knowing what would happen.

The 850W G5 says it can supply 70.8A on the 12V rail. The KD Box specs say it draws 205W +/- 5%

The KD Box is plugged into the VGA 12V rail so it requires the following amount of amps : 205 / 12 = 17.08 amps.

Then if you calculate upper bound with the additional 5% we get 17.08 * 1.05 = 17.94 A

That is per box , so x 4 gives = 71.75 , which is greater than the 70.8 A listed on the 850 G5 specs …

At nominal of 17.08 A x 4 = 69A which is just under the 70.8A on the PSU specs.

The numbers are close, seems it could possibly provide the required amps but im not going to find out …

1000W PSU will allow you to run 4 boxes.