Mac hardware macOS

Radeon RX 580 with Mac Pro


I usually write about my clients’ computing woes, but even Mac consultants have their own problems. A few weeks ago my 2009 Mac Pro starting exhibiting serious issues. I had kernel panics and hard crashes a couple of times a day. When I restarted the machine, it wouldn’t boot most of the time. The fans blasted at full speed, I heard the startup chime, but it just wouldn’t boot. I eventually figured out that when I cranked up the AC, I was able to get the machine started.

It was clear to me that the video card was the likely cause. The kernel panics indicated that the fault was associated with the video driver. The screen freezes and random lit pixels on the screen were also a tip off. Finally, I removed the video card and the machine started every time, without the fans kicking into high gear.

I did a lot of research and settled on a Radeon RX 580 to replace my Radeon HD 4870. This is a mid-range graphics card and supported for eGPU configurations. While this isn’t an eGPU scenario, many people have had success with the 580s and classic Mac Pros. Apple’s official recommendation is the Sapphire Pulse. I took a chance on the overclocked version, the Nitro+. This model apparently has better cooling than the Pulse. Cooling is an extremely important factor in the longevity of a video card.

So far, I’m glad to report that the card is working great. It benchmarks at about 10 times faster than my old 4870. For those considering the RX 580 with their cMP, you must provide the correct power to the card using a special cable. Here’s a plug for a company in New Jersey that sells a suitable cable (dual 6 pin mini male to 8 pin male). The price is reasonable and it was shipped quickly. Alternatively, some people use a cable which adapts the two cables that came with the Mac to the 8 pin male plug.

Note that these new “Windows” ATI cards do not provide Apple’s boot screens such as the Startup Manager and the FileVault login. If this becomes too much of an annoyance, I might buy an older card with Apple’s firmware, such as the Nvidia GT 120. Also note that a 2009 Mac Pro needs its firmware upgraded to the 2010 “5,1” version, so that High Sierra can be installed. macOS Sierra and above include the required ATI video driver. I haven’t seen reports on whether Mojave works correctly with the Nitro+. We’ll know soon enough.

Leave a Reply

Your email address will not be published.