Upgrading the GPU in your old Mac Pro! Is it worth it?

As computer components get faster and more powerful, you may find yourself wondering if your once top-of-the-line Mac Pro can be king again with a little help from a hardware component upgrade. I decided to take an early 2009 Mac Pro and see if a GPU upgrade could bring this once beastly computer back to being on top once more. My inspiration came from NVIDIA's announcement for Mac support for their latest and greatest GPU lineup. The 10xx series, with the uber powerful Titan Xp as its flagship, is the fastest gaming GPU on the market today. Even if macOS isn't considered a gaming OS, could I make it hardware-ready enough to play some Mac-native games decently and perhaps run Bootcamp to setup an impromptu VR gaming rig? Let's find out!

Aiming for the sky!

The plan was to go big or go home. I wanted to get a super powerful GPU in the aged Mac Pro and I wanted to be able to compare capabilities with my Windows gaming PC. I use my Windows PC for VR gaming as it's paired with an HTC Vive. Since my home PC has a monstrous NVIDIA 1080 ti, the Mac Pro was destined for the same GPU. I purchased a Founders Edition version of the 1080 ti from MSI. Although the Mac Pro has 2 old but venerable 2.26GHz Quad-Core Intel Xeon 5500 series processors, I figured that even if they weren't powerful enough to keep the 1080 ti fed with data, the 8 cores could make up for some of the performance deficiencies. More on that later. Here are the complete system specs of the Mac Pro.

• Early 2009 Mac Pro running OS X El Capitan
• 2 x 2.26GHz Quad-Core Intel Xeon 5500 series processors
• 12GB 1066MHz DDR3 ECC SDRAM
• ATI Radeon HD 5770 1024 MB
• 160GB SSD, 640GB sata HDD

Just plug in the hardware and go! Right?

Wrong. There are a bunch of requirements to be met to get new hardware working on a Mac. Unlike Windows or Linux that can accept hardware ubiquitously, Macs can only use hardware specifically designed for Mac OSes and with Apple's blessing (kind of — again, more on that later). In this instance, NVIDIA has already worked with Apple to create drivers for the 1080 ti in beta form. Just double-click the installer and away we go!

Or not. The beta drivers from NVIDIA require macOS Sierra. Not a problem! Just head to the App store. Search for macOS Sierra. Click download and…

Looks like my Mac Pro is too old for macOS Sierra. I could have just done a search on iMore to discover that the cut off date for Sierra on Mac Pros was 2010.

Never give up!

Not to be deterred, I found a number of tutorials on how to install Sierra on an unsupported Mac! This involves disabling SIP or System Integrity Protection and makes your Mac less secure. Therefore, I do not recommend you doing this if you have sensitive data on your Mac. I, however, decided to press on and after some time… success!

Install the drivers and swap in the GPU. What could go wrong?

Plenty. With my new macOS Sierra freshly installed, I was able to successfully install the NVIDIA beta drivers without issue. I shut down the Mac Pro and proceeded with the hardware installation.

1. Flip up the lock.
2. Remove the side panel.

3. Disconnect the 6-pin power cable from the old GPU.
4. Unscrew the expansion card retainer plate.

5. Carefully pull out the old GPU.
6. Slide in the new GPU.

7. Re-attach the retainer plate.
8. Plug in the 6-pin and the 8-pin power cables.

Except the 2009 Mac Pro doesn't have an 8-pin power cable. It only has two 6-pin cables. Each 6-pin power cable provides 75W plus the PCI connector bus provides another 75W for a total of 225W. The 1080 ti needs 250W. No matter! It's only missing a measly 25W. I plugged in the two 6-pin power cables anyway and closed the side panel and fired up the Mac Pro and I waited for the login screen… and waited. Nothing but black. The Mac Pro powered on, but it didn't make the familiar Mac "bing" on start up.

Really. Never give up!

I powered off the Mac Pro and put the old GPU back in and it booted up without issue. I made further google searches and there were a few things I could try, but, frankly, I think that this Mac Pro is just too old to properly power the 1080 ti. After a bit more googling, I came across an excellent tutorial on installing an AMD RX 480. The AMD RX 480 is a recent generation mid-range GPU that is good for 1080p gaming and entry-level VR. This GPU is also not supported on macOS, but at this point I figured I'd try to exhaust all of my options. So instead of going "big" with the NVIDIA GPU, I pivoted to go "medium" with an AMD RX 480. I have a second gaming PC on which I run an Oculus Rift running two MSI Rumor RX 480 4GB. I took one of the RX 480's and placed it into the Mac Pro as per a www.theITsage.com tutorial.

Even though the MSI RX 480 needs an 8-pin port, I know that the reference RX 480 from AMD only uses a 6-pin port, so there shouldn't be any problem powering the GPU.

It's alive! Alive!

Although the Mac Pro boots up without the familiar Apple logo boot screen, the login screen popped up and I was able to log in and run a few before and after benchmarks comparing the old ATI Radeon HD 5770 to the new AMD RX 480. Some benchmarks are synthetic while other's are canned benchmarks from games that run natively on macOS. All benchmarks were run at the most complex graphical settings.

As you can see, there are some very strange results here. Although the RX 480 has some much better frame rates, the variation of FPS was very high. This means that the Xeon CPUs from the Mac Pro are far too weak to properly supply data to the RX 480 GPU. It would have been worse with the 1080 ti.

Was it worth it?

Hell no! Even though I got a new GPU to work in the Mac Pro, the other components being so weak make this a moot point. There is a reason why Apple decided not support some older hardware from being able to be upgraded to newer OS revisions. Even though the 2009 Mac Pro is capable of running macOS Sierra (as proven by me hacking it onto the system), there are myriad other aspects that also have to be up to spec for full functionality. The lack of proper power cables and the weak Xeon CPUs on this Mac Pro make upgrading the GPU nearly pointless, since gaming with such a highly variable frame rate would prove maddening. This is not to say that upgrading your GPU on other Mac hardware is a lost cause. In fact, I've decided to order an eGPU (likely the AKiTio) so that I can pair it up with a modern MacBook Pro and remove the issues of CPU bottlenecks and power delivery.

So, my attempt at bringing new life into an old Mac Pro wasn't a complete failure. At the very least, I now have the latest version of macOS running on the box.

Have you tried to upgrade your Mac Pro? How'd it go? Let me know in the comments below!