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matthewpomar

macrumors member
Original poster
Oct 27, 2010
78
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I'm going to use Open Core Legacy Patcher to bring my classic Mac Pro up to date so I can use it again as my daily driver. I plan on running Ventura or Sonoma, depending on recommendations.

It currently has a Sapphire RX 580 PC card with no boot menu support. I understand OCLP will add boot menu support, but I am also looking to drive the a Dell 6K monitor at 60Hz. From what I can tell, this card will not support this resolution.

Any recommendations on a video card that:

1. Fastest card that supports 6k (6,144 x 3,456 @ 60Hz)
2. Works (supported) with Venture and/or Sonoma via OCLP.
3. Does not require any power modifications.

This will not be used as a gaming machine, but rather video editing, programming, and daily work/office use.

Thanks so much!
 
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I have nothing to offer besides that I too am very interested to see what is recommended! I'm rockin my 580 with OCLP Monterey on my 5,1, used for 3D parametric modeling in Solidworks (Windows 10 VM) and CPU rendering with Keyshot in MacOS. I have two 30 inch cinemas but I realize that my card could probably do another 2 no problem. Your needs definitely exceed mine but I do edit the occasional video in Final Cut and it's never been the fastest. Very interested to see what's suggested!
 
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Is this where people are coming from when they say the move is to run Windows 11 on these machines going forward? I have heard that MacOS is not the most logical decision for 5,1 machines anymore.

It's also an unsupported hardware configuration with Windows 11 that can stop working anytime and even if you move to Windows, you still have to protect the Mac Pro BootROM from Windows UEFI SecureBoot signing that can brick the Mac Pro with OpenCore.

So, for a smooth ride, Linux seems a more reasonable choice for the long run.
 
It's also an unsupported hardware configuration with Windows 11 that can stop working anytime and even if you move to Windows, you still have to protect the Mac Pro BootROM from Windows UEFI SecureBoot signing that can brick the Mac Pro with OpenCore.

So, for a smooth ride, Linux seems a more reasonable choice for the long run.
Terrifying! I just set up a CNC machine with Debian 12 and LinuxCNC, I hadn't used Linux since middle school ('00s)! Perhaps as a last resort. I guess I need to do more research re: UEFI because I thought I was good to go :( *edit* I have to apologize to OP for hijacking this thread, I'm still curious to hear from others suggesting hardware for OP.
 
Well, I checked a few more sources and it appears that the RX580 might support at 7680 x 4320 resolution. It supports DisplayPort 1.4, which supports:

7680 x 4320 / 60 Hz / 10 Bit Chroma / HDR
and
3840 x 2160 / 120 Hz / 10 Bit Chroma / HDR

... according to this site:


So, I guess I'm good with Sonoma or Ventura with this card for the Dell 6K monitor. Does anyone have any information to the contrary?
 
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Be aware. I have an RX-580 (flashed) in my CMPro 5,1 and Sonoma and Ventura are not stable with 1.3.0 or 1.4.0 nightly routinely kernel crashing in the video driver. The AVX2 patch appears to be incomplete.

When I politely inquired for more info on Discord, Macschrauber was helpful, others were more "curt." Not sure, why the defensiveness.

Overall I like the RX-580. I got it when I had High Sierra and it required a patched driver. It worked well with stock Mojave, DosDude patched Catalina, Big Sur, and Monterey. But not the new systems. If I remember Ventura used to be ok. It might be the OCLP 1.3.0 patches made things worse. I have not tried reverting.
 
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I think a flashed 6600 XT is the best modern card going forward for a Mac Pro if you do not want to do power mods. It’s what I have and it is a very capable modern cpu with windows support expected for the foreseeable future, as well as relatively seamless modern Mac OS support.
 
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Personally I'd stick with Monterey if I were still using a 5,1, as I wouldn't want to put up with potential instability for the minor improvements of Ventura / Sonoma. Realistically, though, I think we all got our money's worth out of these old machines, and are better off moving on to something (vastly) more modern.

The issue, of course, is that the cMP doesn't really have a successor. The 2019 is still expensive second hand, and on borrowed time in terms of OS support. You basically can't have your cake and eat it any longer. You can either have macOS, and forego expandible hardware (with a mini / Studio), or have expandible hardware and forego macOS. Sticking with a 15 year old machine is not a solution - you have to bite the bullet at some point.
 
a flashed 6600 XT is the best modern card going forward for a Mac Pro

I have the same RX6600XT Sapphire card on my 12.7.4 Monterey machine - it works very nicely. Also doesn't push out anywhere near as much heat as the RX580 used to do.

Fortunately I had a 7,1 Mac Pro (I got it brand new) that runs windows so I just put the RX6600XT in a EGPU enclosure and connected it to the 7,1 and flashed it that way.

Ultimately professional level computing on the Apple side is dead. If you want traditional Mac Pro level hardware you have to go to HP or Lenovo these days and one of their workstation offerings. Those are nice but equally expensive like the 2019 Mac Pro (although nobody complains about the cost).
 
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Those are nice but equally expensive like the 2019 Mac Pro (although nobody complains about the cost).

I guess people buying PC workstations specifically want a workstation, whereas the people who own second hand 5,1's just want an expandible desktop Mac, which otherwise doesn't exist. The other thing is that PC workstations at least give you AMD CPU and Nvidia GPU options for the money.
 
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Well, I checked a few more sources and it appears that the RX580 might support at 7680 x 4320 resolution. It supports DisplayPort 1.4, which supports:

7680 x 4320 / 60 Hz / 10 Bit Chroma / HDR
and
3840 x 2160 / 120 Hz / 10 Bit Chroma / HDR

... according to this site:


So, I guess I'm good with Sonoma or Ventura with this card for the Dell 6K monitor. Does anyone have any information to the contrary?
I used an RX570 4G ITX card with Mod ROM. support Maximum digital resolution: 7680 x 4320 via DP.
 
I used an RX570 4G ITX card with Mod ROM. support Maximum digital resolution: 7680 x 4320 via DP.
Do those RX580s or 570s have enough power to be able to drive that kind of resolution?

They might do it, but does the whole thing struggle and become unworkable in actual use?
 
Do those RX580s or 570s have enough power to be able to drive that kind of resolution?

They might do it, but does the whole thing struggle and become unworkable in actual use?
If you use it for monitoring no problem, but if you need 3D workflow with GPU computation or acceleration, then NO.
 
I'm the OP on this thread. To tie it up, RX 580 won't do more than 5K over DP, according to the Sapphire website:
  • DisplayPort: 5120×2880@60Hz
  • HDMI: 4096×2160@60Hz
  • DVI:2560x1600@60Hz
I could never get more than 4k @ 60Hz.

I abandoned Sonoma due to the instability caused by outdated CPU in Mac Pro 5,1. Moved to Montery and it's stable and trouble free.

Replaced RX 580 with RX 6600 from MacVidCard EU. Despite their site advertising the card to support 8k @ 60Hz, I'm only able to get 6k at 30Hz, or 5k @ 60Hz on my Dell 6k monitor over DP, trying many different cables. Given this card has a PCI gen 4 x 8 connector, I can only conclude the Mac's PCI gen 2 slot doesn't provide enough bandwidth to hit 6k @ 60Hz. I suspect a gen 2 x16 card could work, but I have chased this rabbit long enough.
 
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Doubt the PCIe slot has anything to do with it. It will be related to the spec of the DP connector on the card, and more likely, Apple's AMD drivers. Showing your desktop at 6K60 won't be taxing the PCIe bus.
 
I'm the OP on this thread. To tie it up, RX 580 won't do more than 5K over DP, according to the Sapphire website:
  • DisplayPort: 5120×2880@60Hz
  • HDMI: 4096×2160@60Hz
  • DVI:2560x1600@60Hz
I could never get more than 4k @ 60Hz.

I abandoned Sonoma due to the instability caused by outdated CPU in Mac Pro 5,1. Moved to Montery and it's stable and trouble free.

Replaced RX 580 with RX 6600 from MacVidCard EU. Despite their site advertising the card to support 8k @ 60Hz, I'm only able to get 6k at 30Hz, or 5k @ 60Hz on my Dell 6k monitor over DP, trying many different cables. Given this card has a PCI gen 4 x 8 connector, I can only conclude the Mac's PCI gen 2 slot doesn't provide enough bandwidth to hit 6k @ 60Hz. I suspect a gen 2 x16 card could work, but I have chased this rabbit long enough.
Hi. I also have a 5,1 and use OCLP (Monterey) and get 6K60 resolution output via an AMD 5700XT Anniversary Edition. No power mods!

It's not about the PCI bandwidth limitations. Are you trying to connect to a Pro Display XDR? That's what I have.

Almost forgot to mention, you need SwitchResX in order to get the full resolution support.
 
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Just to provide some reliability info thus far on the Radeon RX 5xx series: I have a small fleet (20+) of these beasts in a cash-starved non-profit EDU environment (long story, I'm aware it makes little sense, but it is what it is). We have been running 560s, 570s and 580s generally without any issues, across Monterey, Ventura and Sonoma. No stability issues on machines that are used daily for a substantial variety of tasks (3d printer/modeling workstations, office work, video editing and transcoding, media servers, caching server, gaming when nobody is watching, etc. etc.) I use a RX 580 in two personal workstations, and frequently nail both the CPU and GPU for sustained periods of time. Same is holding true for student machines used for 'edutainment' titles such as Universe Simulator, which will completely saturate all 12 CPU cores and GPU. So, overall, good news I think in terms of what users can expect from the RX 5xx series. The 560s display garbage at boot, but work perfectly once booted. Having excellent luck (so far) with EnableGOP as well.

I currently drive dual displays including a 4k monitor at 2560x1440 in 'Retina' mode, and performance is decent, but not fantastic.

So looking around now to see if I can push it any further for another couple years of usability. It appears we are at the point where more powerful AMD cards are not being supported in Ventura and newer? Is the RX 580 indeed the most powerful GPU that works reliably at this point?
 
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#3.

At this time, you're stuck on AMD Polaris, if any macOS newer than Monterey (Ventura, Sonoma) is mandatory for you.
Vega 64 is the powerful card you can get, but requires power cable mod.
 
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E
#3.

At this time, you're stuck on AMD Polaris, if any macOS newer than Monterey (Ventura, Sonoma) is mandatory for you.
Vega 64 is the powerful card you can get, but requires power cable mod.

OK, thanks. That's probably doable for a couple of task-specific machines. I'll just use an external power supply rather than the power cable mod (as I have old power supplies laying around from gaming rigs anyway).

Do we know if there are specific models of Vega 64 cards that work properly?

Alternatively, it looks like the Vega 56 cards should work also, and likely don't have the power-requirement issue? Looking at performance it seems the the Vega 56 should still offer a decent uptick in performance of the RX580 (40%ish?) Is there some reason we don't consider Vega 56 cards? (It makes little sense to bother with any of this, performance uplift just isn't that much, but I need to supply RX 580s on few more machines currently on RX 560s, so if I'm doing this anyway it makes sense to upgrade a couple of the most important machines and then pass the RX 580s down the chain.)

Speaking of which, do we know any current RX 580 models that are working without issue? Now that the line has gone 'bargain bin' I expect a lot of these new RX 580s out there won't work?
 
Vega 56 will also work, but has the same issue with extremely power consumption.

Maybe you can optimize performance and reduce power with slightly undervolting the GPU.
 
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lot's of great advice.

my personal recommendations - if using ventra or sonoma:
1) RX 480/580
2) Vega 56/64 or Radeon VII (pixlas mod highly recommended/pretty much necessary for these)

If using Monterey,
3) RX 6600 or XT variant
4) RX 6800 (pixlas mod recommended)
5) RX 6800 XT (pixlas mod highly recommended/pretty much necessary)

after monterey, avx requirement was added to the video drivers, but OCLP team added patches so this requirement was removed on cards from 1 and 2 in ventura and sonoma. 3-5 are currently WIP for ventura or sonoma.

it depends on your needs. for example, the latest FCP requires ventura as minimum OS (which i use). I am going to add pixlas mod to my mac since I have a Radeon VII, that way i can be sure the power draw won't shut down my machine
 
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Just a heads-up for those trying to snag 580s in 2024+: The current 580s out there all seem to be using a 6 pin power connector, instead of the 8 pin. Other than one or two (very overpriced) Sapphire 580s I'm seeing nothing that will plug-n-play with existing dual-mini-6 to single 8 pin cables, etc.

(If anyone is successfully using these newer 580 cards please let me know. At this point I can't even find a cable that would allow me to test such a card to see if it is functional.)
 
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