This is spread across a few threads and some websites, but I'm hoping that if someone runs into the same things I did they might match this post on a search quickly and save themselves some time.
TL;DR important notes for the NITRO+ RX580 card:
I have a Mac Pro 4,1 EFI'd up to a 5,1.
I had a Gigabyte Radeon 6870 GV-R6870C-1GD card hooked up via minidisplay port to displayport cables to a Dell 3415 and a Dell 2815 (4k) display. The 6870 required two mini-6PIN to 6PIN power cables. No idea how I was driving 4k out of it when it's not listed in the specs.
I bought a Sapphire Nitro+ RX580 (not the Pulse RX580) card. This card has 2xDP, 2xHDMI, 1xDVI and had a 8PIN power and 6PIN power connector on it.
OS:
Nothing to do. Like any non-Mac EFI card, you won't see the gray apple boot screen. Eventually the login window pops up.
POWER:
The manual for the card is rubbish. It stated the 6PIN was "optional" and didn't state that you needed to drive main power through the primary 8PIN connector. If you have two seperate 6PIN cables like I did you'll need to get a dual 6PIN to 8PIN adaptor and plug it into only the 8PIN port...don't bother with the optional. If only do one 6PIN to 8PIN convertor and plug the other 6PIN into the secondary port, you'll still experience issues of not enough power. (each 6PIN plug on the MB drives 75Watts, combining them with a cable gives 150W through one 8PIN connector).
I used https://smile.amazon.com/gp/product/B0749DQ3VX/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
While I was waiting for that to arrive I was able to power the card correctly using a dual SATA to 8PIN cable I had where I disconnected the internal DVD drive and used those two power cables, but then I swapped back to the above when the cable came.
CABLING:
Even though the MDP->DP cables worked just fine on the 6870 and I did not change the resolutions of the displays (they were both running native max), these cables didn't work at all for the RX580 card. Don't know why. I would assume because they were only DP1.2 cables but I had a set of DP->DP cables from Microcenter that said they are DP1.2 cables. This worked, but the video quality was poor, there was color bleeding off the edge of fonts. I'm now ordering DP1.4 cables from Monoprice.
In the interim, I'm running HDMI 2.0b cables to the monitors and they look crystal clear. (Just I need one of the HDMI's for a PIP Tivo unit, so I need to change it back to DP when the cables arrive.
Radeon RX 580:
Chipset Model: Radeon RX 580
Type: GPU
Bus: PCIe
Slot: Slot-1
PCIe Lane Width: x16
VRAM (Dynamic, Max): 8192 MB
Vendor: AMD (0x1002)
Device ID: 0x67df
Revision ID: 0x00e7
Metal: Supported, feature set macOS GPUFamily1 v3
Displays:
DELL U3415W:
Resolution: 3440 x 1440 (UWQHD - Ultra-Wide Quad HD)
UI Looks like: 3440 x 1440 @ 60 Hz
Framebuffer Depth: 24-Bit Color (ARGB8888)
Display Serial Number: 68MCF5560N5L
Main Display: Yes
Mirror: Off
Online: Yes
Rotation: Supported
Automatically Adjust Brightness: No
DELL P2815Q:
Resolution: 3840 x 2160 (2160p 4K UHD - Ultra High Definition)
UI Looks like: 3840 x 2160 @ 30 Hz
Framebuffer Depth: 24-Bit Color (ARGB8888)
Display Serial Number: WJJGR45AA2MM
Mirror: Off
Online: Yes
Rotation: Supported
Automatically Adjust Brightness: No
TL;DR important notes for the NITRO+ RX580 card:
- It works.
- Get 6PIN+6PIN (150W max) -> 8PIN , ignore the second 6PIN on the graphics card. If you use single 6PIN->8PIN (75Watts Max) or a 2SATA -> 8PIN (108Watts Max) you'll be able to drive the card but the system will freeze at when it hits the point that the card wants more power going into "safety" mode. The card actually may still under heavy load as it's "overclocked" RX580 and articles I've found said it can pull up to around 210W at full load - this will require a supplemental power, which is easy to add externally and I might do so in the future anyway. I just don't game much at the moment.
- Make sure your cables are DP1.4 or HDMI 2.0b
I have a Mac Pro 4,1 EFI'd up to a 5,1.
I had a Gigabyte Radeon 6870 GV-R6870C-1GD card hooked up via minidisplay port to displayport cables to a Dell 3415 and a Dell 2815 (4k) display. The 6870 required two mini-6PIN to 6PIN power cables. No idea how I was driving 4k out of it when it's not listed in the specs.
I bought a Sapphire Nitro+ RX580 (not the Pulse RX580) card. This card has 2xDP, 2xHDMI, 1xDVI and had a 8PIN power and 6PIN power connector on it.
OS:
Nothing to do. Like any non-Mac EFI card, you won't see the gray apple boot screen. Eventually the login window pops up.
POWER:
The manual for the card is rubbish. It stated the 6PIN was "optional" and didn't state that you needed to drive main power through the primary 8PIN connector. If you have two seperate 6PIN cables like I did you'll need to get a dual 6PIN to 8PIN adaptor and plug it into only the 8PIN port...don't bother with the optional. If only do one 6PIN to 8PIN convertor and plug the other 6PIN into the secondary port, you'll still experience issues of not enough power. (each 6PIN plug on the MB drives 75Watts, combining them with a cable gives 150W through one 8PIN connector).
I used https://smile.amazon.com/gp/product/B0749DQ3VX/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1
While I was waiting for that to arrive I was able to power the card correctly using a dual SATA to 8PIN cable I had where I disconnected the internal DVD drive and used those two power cables, but then I swapped back to the above when the cable came.
CABLING:
Even though the MDP->DP cables worked just fine on the 6870 and I did not change the resolutions of the displays (they were both running native max), these cables didn't work at all for the RX580 card. Don't know why. I would assume because they were only DP1.2 cables but I had a set of DP->DP cables from Microcenter that said they are DP1.2 cables. This worked, but the video quality was poor, there was color bleeding off the edge of fonts. I'm now ordering DP1.4 cables from Monoprice.
In the interim, I'm running HDMI 2.0b cables to the monitors and they look crystal clear. (Just I need one of the HDMI's for a PIP Tivo unit, so I need to change it back to DP when the cables arrive.
Radeon RX 580:
Chipset Model: Radeon RX 580
Type: GPU
Bus: PCIe
Slot: Slot-1
PCIe Lane Width: x16
VRAM (Dynamic, Max): 8192 MB
Vendor: AMD (0x1002)
Device ID: 0x67df
Revision ID: 0x00e7
Metal: Supported, feature set macOS GPUFamily1 v3
Displays:
DELL U3415W:
Resolution: 3440 x 1440 (UWQHD - Ultra-Wide Quad HD)
UI Looks like: 3440 x 1440 @ 60 Hz
Framebuffer Depth: 24-Bit Color (ARGB8888)
Display Serial Number: 68MCF5560N5L
Main Display: Yes
Mirror: Off
Online: Yes
Rotation: Supported
Automatically Adjust Brightness: No
DELL P2815Q:
Resolution: 3840 x 2160 (2160p 4K UHD - Ultra High Definition)
UI Looks like: 3840 x 2160 @ 30 Hz
Framebuffer Depth: 24-Bit Color (ARGB8888)
Display Serial Number: WJJGR45AA2MM
Mirror: Off
Online: Yes
Rotation: Supported
Automatically Adjust Brightness: No
