I'm pretty much in the same boat as you, and I decided to just go for the EVGA Powerlink. Seems to be the easiest, safest and cheapest option.
You can use 2 miniPCIe 6-pin to 6-pin with Powerlink, no problem. Internally all +12V are bridged.Well, everything arrived today and it was very disappointing.
1. The Powerlink has two 8pin connections (not a 6pin and an 8pin) when connecting the power cables. Sure, you can change out the 8pin to a 6pin to connect it to the video card, but you still need two 8pin connections to provide the power.
2. The internal SATA connections are the extended power/data SATA connections and the Y cable that I was told to order does not work with these types of connections. Plus, that Y cable is dual SATA power (only) to 6pin not 8pin which is what is required with the Powerlink.
3. While moving a drive or two up to the DVI cage was mentioned, no reason was ever given as to why that is an absolute necessity. For anyone reading this, it is necessary to free up bays 2/3 from connected hard drives so you have SATA connections on the logic board to use to power the video card. Otherwise, there is no way to route the cable and put the Mac Pro chassis side panel on.
So, if you have a Mac Pro 4,1 or 5,1 here's what you need:
OWC Drive Mount Adapter (only required if you have more than 3 hard drives in the sled bays)
OWC Multi-Mount for 2009-2012 Mac Pro
Add more storage to your 2009-2012 Mac Pro by utilizing the spare optical drive bay with a 5.25" hard drive.eshop.macsales.com
EVGA Powerlink
EVGA PowerLink, Support All NVIDIA Founders Edition & All EVGA GeForce RTX 2080 Ti/2080/2070*/2060*/Super*/GTX 1660 Ti*/1660*/1650/1080 Ti/1080/1070 Ti/1070/1060 0600-Pl-2816-Lr
The EVGA powerlink is designed to provide both a more stable power source and reduce ripple and noise, compared to connecting your power supply directly to the graphics card. The EVGA powerlink has another function: to make your PC look even more awesome. This adapter allows you to reroute the po...www.amazon.com
8pin to Dual Mini-6pin Cable (this connects to the EVGA PowerLink)
COMeap Dual Mini 6 Pin to 8 Pin PCI Express Video Card Power Adapter Cable for Mac Pro Tower/Power Mac G5 15-inch(38cm)
COMeap Dual Mini 6 Pin to 8 Pin PCI Express Video Card Power Adapter Cable for Mac Pro Tower/Power Mac G5 15-inch(38cm)www.amazon.com
Dual SATA 15pin (male) to 8pin
J&D 8 Pin to SATA Power Cable, (2 Pack) 2X SATA to 8 Pin PCI Express (PCIe) Graphic Video Card Power Cable Adapter, 8 inch
J&D 8 Pin to SATA Power Cable, (2 Pack) 2X SATA to 8 Pin PCI Express (PCIe) Graphic Video Card Power Cable Adapter, 8 inchwww.amazon.com
SATA 22pin to SATA 15pin and 7pin Breakout Cable (qty 2)
SATA 22 Pin Male to SATA 7 Pin and 15 Pin Female
SATA 22 Pin Male to SATA 7 Pin and 15 Pin Femalewww.amazon.com
Here's how it works:
1. Relocate your hard drive(s) to the DVI cage if necessary
2. Connect the Powerlink to your video card
3. Connect the dual mini-6pin to the logic board A/B connections and the 8pin to port 1 of the Powerlink
4. Connect both of the SATA breakout cables to SATA ports 2/3 (the corresponding drive bay numbers)
5. Connect the Dual SATA to the 15pin female ports of the breakout cable and the 8pin to port 2 of the Powerlink
That's it!
If you had to do all this for your GPU to work, maybe you have power problems with your GPU or your Mac Pro PSU.
Why MUST a HDD bay be occupied to have to resort to that monster?A single ODD SATA connection is not going to provide the 75 W a 6 pin PCIe booster connector on the GPU expects . No where even close . You need to work off the backplane and grab 33 W + 33 W from two SATA HDD Bay connectors . If your SATA HDD Bays must be occupied with HDDs , then an alternative is to use an external PSU and drill holes into the side access panel of your Mac .
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