Here are the facts from Thermaltake and I quote!
Hello Peter,Thank you for contacting Thermaltake Customer Service.
The -5v rail is no longer used for CPUs or motherboards. It has not been used since the first P4 and socket A. Only older systems will require the -5v. Newer motherboards and CPUS are now using ATX series 2.0 or higher standards. With this, they no longer require a -5v to operate. Therefore, new power supplies are not manufactured with a -5v rail.
I guess my next question will be directed at BFG and the vid card.
I recently decided to try upgrade my Gigabyte GA-P35-DS3L based system from an PNY Nvidea 8500 Vid card to a BFG Nvidea 260 based card. I realized this would require a beefier PSU than the 450 watt I had in the system so I purchased and installed a new Thermaltake TR2 RX-850 Modular Power supply. After connecting the MB to the PSU (including the 4 pin connector next to the CPU socket) and connecting the dedicated PCIe power cables to the vid card I tried to start the system up. The fan on the vid card never even spun up. The fans on the Mobo were spinning away so I was a bit confused. I had a PS tester at hand so I hooked it across the 24 pin connector and discovered that the -5 volt indicator was not lighting up. I repeated the test with the old PSU and that indicator did light. Thinking it was an issue with the Thermaltake unit I returned to the point of purchase to swap it for another. I took the tester with me to confirm that the next PSU was working properly. It failed to light that same -5 volt indicator as well. The Geek squad guys said that was normal and that the power supply was likely not compatible with that model Mobo. Is that possible? I poked arouns a bit on the Gigabyte sight and the thermaltake sites but never did find any compatibility charts. I know this isn't the latest and Greatest Mobo but its rated up to quad core and even extreme duo processors so I made an assumption that this combo would work. So much for assumptions. Now I am going to make this a project box but want to get a Mobo and CPU combo that will work with all the other parts I have on hand. Any thoughts?