I wanted to give my take on the Sapphire Radeon Nitro+ RX 580 8GB (11265-01-20G) I kind of went over this on this thread #9 It was in short and that thread was pertaining to another issue non related to the Nitro+. As some of you may know or have heard about it being too high that it blocks the 2nd PCIe slot on the MacPro. I wanted to take a chance to clarify on it since it wasn't entirely clear if it truly blocks the 2nd PCIe slot from being used or if there is just enough room for a PCIe card to be placed on the 2nd slot. This is what I can say; Yes you can put another PCIe card on the 2nd slot. However it entirely depends on what PCIe card you install, additionally you will have to remove something to make just little more clearance. Let me explain. For most, you may not even need the 2nd PCIe slot so having the Nitro+ is a good card to have. Also, I highly recommend doing the Pixlas Mod It may be intimating to do but its well worth it. I couldn't find the Yellow T-Taps locally so I went with the Blue T-Taps that they had at my local auto parts store. I did use some dielectric grease on all my connections, you might not need that but I did that for my own setup. If you need to use the 2nd PCIe slot this what you have to do. 1st is to remove the gray plastic pad that lays on top of the CPU cage, by removing this it will give the Nitro+ just enough to sit just a little lower or even perfect on its slot. If the gray plastic pad were left in place, it would 'kick-up' the card in an awkward angle, this is because the Nitro+ and even the Pule have an aluminum heatsink plate on the bottom that protects it. The plastic pad is only held on by some adhesive and its easy to remove with a plastic wedge tool or spudger. Lastly, you'll have to do a PCIe card shuffle, what I mean is you'll have to find the PCIe card with the least protruding IC's, or even better, no protruding IC's on the bottom of the PCIe card you want to install on the 2nd slot. This might mean you may have to shuffle you PCIe cards around till you find one with the least, or no pro protruding IC's on the bottom of the card. In my case I have a Blackmagic Intensity Pro that is perfectly flat on the bottom. So this is how I have my setup. 4th Slot - USB 3.0 card 3rd Slot - NVMe PCIe card 2nd Slot - Blackmagic Intensity Pro 1st Slot - Nitro+ Of course you milage may vary on what cards you have and if there is any IC's protruding enough to hit the fans of the Nitro+. I was able to install windows on a separate SSD so I can play some windows games on the Nitro+ What I love the most is now I can have 3 monitors going, where as with my 7970 I could only have two monitors. I have two 23in Apple Cinema Displays via active Displayport to DVI adapter and my HDTV hooked up via HDMI. Obviously, no boot screen. All in all, in my case everything worked just fine and I'm very happy with everything.