EVGA PowerLink

Nice, simple, does exactly what it is supposed to do. It takes any combination of 6 pin and 8 pin inputs, connects all of the 12V lines in parallel, and then feeds it out. This results in power being pulled fairly evenly over both of the inputs rather than lopsided. For outputs it is set up for 8 + 8 by default, and there is one 6 pin output you can use instead of an 8 pin. The pamphlet in the package says that it is possible to request a second 6 pin output if you have a 6 + 6 card. I have a Mac Pro 5,1 with an Nvidia GeForce GTX 980Ti with a 6 pin and 8 pin auxiliary power input. Watching the amperage via iStat Menus I could see one drawing 7.5 - 8 amps and the other drawing 5 - 5.5 amps. With this connected it's now pulling about 6 - 6.5 amps from both. The Mac Pro will shut off if the power draw on one of the PCIe auxiliary power connections is too high in order to protect itself, something I ran into that a few times shortly after I got the card and was testing it out. To prevent that from happening while I was playing games under Windows I wound up using MSI Afterburner to limit the card's power draw to 90% of maximum. Once I had that configured I no longer ran into any abnormal shutdowns, but it also meant that there was some performance capacity still available that I couldn't use. After installing the PowerLink and seeing how it balanced the power draw over both auxiliary connections, I updated the Afterburner configuration so the card could pull 100% power again and run at full performance. After many, many hours of gaming I have yet to experience an unexpected shutdown. Update: Took some screen shots showing the power distribution with and without the PowerLink installed. Going through that process I found one minor little annoyance: it's difficult to remove the PowerLink from the video card when it is installed. The clip that holds it into the card can't be depressed to remove it. Instead, you need to take something tiny, like a plastic spudger, and slightly tilt the clip to release it. Not difficult, but it took me a few minutes before I realized I needed to do that. I also opened up the PowerLink and took some pictures of the inside in case anyone is curious. It does do a little bit more than just connect all of the 12v pins in parallel, but not much. The main thing to notice in the pictures is how lopsided the power draw was without the PowerLink installed. It was pulling 8 amps from the A feed but only 4.5-5 amps on the B feed. Skimming through the forums I ran across the theory that the sensor won't report higher than 8 amps while the protection mechanism kicks in (shuts off the machine) at 10+ amps. If that's true then the 8 amps that is shown on the boost A connection may actually be a bit higher than that. Also, while going through this I noticed that the PowerLink was pulling slightly more power from the lower plug than the upper. I think the maximum difference I noted between the two was about .5 amps briefly, but it was usually around .2 amps or less. Basically there was just enough of a difference to be noticed, but that's all. It's still far, far better then the 4-5 amp difference seen without the PowerLink. Anyway, I am still extremely pleased with the PowerLink. If you have one of the older Mac Pros (5,1 or earlier), and want to run one of the newer video cards, get this. While I can't guarantee it will prevent abnormal machine shutdowns due to pulling excess power from one of the PCIe aux power connections, it will absolutely reduce the likelihood.