How to Fix Error 173 on Intel Mac Pro dGPU

by Rian

Of many things Apple Silicon brought, I am still curious whether or not Apple is willing to bring dGPUs into Mac Pro lines of their products. Despite how useful other PCI-based cards may be, most users, at least the ones that are most vocal, express their desire to use more powerful graphics card on Mac Pro, like it used to be.

Symptoms

Mac Pro is sold with a default MPX graphics module regardless of customizations. So I am assuming the problem occurred while trying to add a third-party PCI graphics card to Mac. On macOS, as far as I am aware, the end user doesn’t need to install AMD software to update the drivers, and therefore AMD does not offer one. It only happens on Bootcamp Windows.

I may be sounding like a broken record at this point, but Intel Mac Pro, released in 2019, is the last Mac that supported dGPU or eGPU. If your Mac is running on Apple Silicon, AMD’s error message is the expected behavior. Likewise, I am assuming this problem occurred on Mac Pro running Windows natively via Bootcamp; Apple Silicon Macs currently do not support running ARM Windows natively.

I’d assume other PCs may be suffering from the similar issues. Error 173, in AMD’s description, says that AMD software failed to detect AMD graphics card on your computer. The irony of this message is that Windows device manager does pick up the card proper with the stock Microsoft driver.

My attempt to erase the stock Bootcamp drivers and reinstall them with the community provided latest driver was quite futile. In fact, the newly installed driver conflicted with the Microsoft-provided driver, presumably when Windows tried to pull updates for the drivers after the reboot.

Solutions

This is a band-aid fix, as most Mac Pro users would want to use multiple graphics card for their purpose. But, as a band-aid fix, you can install the latest driver for one specific graphics card.

I also assume this will apply to any regular PC builds that have more than one graphics card, especially old and new installed side by side.

1. Physically remove any other graphics cards, including MPX modules, from the system. Leave one graphics card in question installed.
2. From AMD website, download the latest graphics card software.
3. Installation will continue proper without the error message.

It may be possible to reinstall the other cards, but I wouldn’t advise it. I’m not sure if AMD software can handle seeing multiple cards.

Afterthoughts

I was quite puzzled AMD does not offer bare bone drivers on its website. In fact, I couldn’t find much discussions on people wanting to install purely the drivers and drivers only.

As for running multiple graphics card, I do recall ATI (now bought out by AMD) CrossFire. I don’t know the specifications behind the technology, let alone the application for modern day usage. If I were to hazard a guess, CrossFire is quite unrelated in this case, as the user is not attempting to use both cards simultaneously for one task.

Side note, I did read somewhere the workstation level graphics cards on Mac Pro and MPX modules have its own applications for professional users; there may be some merit to invest into MPX modules, should Apple announce the future support of them. The one of the earlier posts I’ve written did cover a similar situation where a particular graphical glitch only occurred on non-workstation graphics card; it may be entirely up to the driver’s fault, however.

I’ll keep the post updated if I find out more about it.