I'm building a system using a case that comes with customized wiring, including a 6-pin cable that goes directly from the PSU to a drive cage with PCBs at the front of the case (drives just plug in rather than having individual power connectors).
 
The 850 has three 6-pin ports labeled "SATA" and another one labeled "Perif".  They all use the same type of connector but I don't know which pin is what (gnd/5v/12v) and I need to rearrange the pins in the case's cable to match.  I've already tested the cable's connector itself at it fits, but I'm not about to turn anything on until I make sure the pins match up.
 
I found an article on overclock.net ("Repository of Power Supply Pin Outs") which has a lot of pinout diagrams, including various EVGA SuperNOVA G2's and P2's.  However, I don't know if the pinouts are the same between those and the T2's.  Does anyone know?

The component-end (that connects to the mobo, drives, graphics cards, etc.) pinout is industry standard as specified by Intel..However, there is no industry standard for the PSU-end pinout and can vary from manufacturer to manufacturer and even between different models/versions of the same PSU from the same manufacturer..You can go by the "Repository of Power Supply Pin Outs" or any of the other widely published and available industry standard ATX pinout charts such as from Pinouts.ru or the Power Supply 101: A Reference Of Specifications over at Tom's Hardware for component-end pinout, all the same..If in doubt, you can pick up an el cheapo digital voltmeter for 10 - 15 bones and verify for yourself..Proprietary PSUs such as from Dell and others can have different pinouts, but mainstream/standard PSUs such as from EVGA, Corsair, Cooler Master, Thermaltake, Seasonic, etc. that are available through Newegg and other such retailers are the same.

Thanks!  Since I wanted to be 100% sure, I used a voltmeter and found that the SATA pinouts on the back of the PSU match the G2 and P2 diagrams.  Even the Perif connector was the same as the SATA ones, including the 3.3v pin.  Of course, the cable labeled "Perif" doesn't use this pin.
 
One thing, though--the volt readings on all pins were a lot higher than I expected--3.3 was 4.5, 5 was 6.5 and 12 was 16.  I had no load on the PSU--I activated it using the dummy connector that comes with it to turn it on without connecting it to a motherboard and had no fans/pumps/drives/etc. attached.  Is this normal?

Might want to back-probe the 24-pin connector or check at a 4-pin peripheral connector when you get your PC running and see what voltages you come up with..may be a good idea to contact EVGA Support and find out if it's okay to test that unit with no load, which can matter (my PSU don't matter)..Maybe one of the Forum Techs/Mods will chime in on it.
 
While not as accurate as using a multimeter, you can check the voltages in the BIOS or with software such as AIDA64 Extreme (free trial) or HWiNFO..Somtimes the software is way off though, but BIOS readings or those of any monitoring software that came with your mobo or can be downloaded from your mobo manufacturer should be extremely close to actual.