Monday, July 1, 2019

Gaming With a MacBook Pro and eGPU

Justin Searls (tweet):

So, it’s thanks to the trash can Mac Pro that in 2019, it can truthfully be said: instead of putting a beefy graphics card inside your computer, you are now able to take a top-of-the-line gaming GPU, seat it inside an external box, plug that box into your computer, and—using a single high-bandwidth cable—push the necessary instructions to render 4K games at 60 frames per second on the card before (over the very same cable!) pushing those frames back to your notebook’s built-in monitor without introducing any perceptible latency. I’ve seen daily evidence of this for the last month and I gotta say: it’s pretty freakin’ cool.

The idea that you’d be able to connect a GPU over a 2-meter cable and get desktop-class gaming performance out of the current crop of MacBooks Pro seems far-fetched. Even to me, as I literally play games with one. When reasonable people encounter Apple’s marketing about eGPUs—which is only focused on creative professional workflows like modeling VR experiences as opposed to experiencing them—it would be unreasonable to make the logical leap to say, “ah, yes, surely if I boot that computer into Windows, the eGPU enclosure would have the necessary drivers and the Thunderbolt 3 cable would have the necessary bandwidth to render games in real-time with an acceptable frame rate and input latency.”

[…]

Congratulations, you’re now too tired to want to play any games with your now-capable-of-running-them MacBook Pro.

7 Comments RSS · Twitter

Ghost Quartz

“You're first supposed to tell macOS to force restart any apps that are currently depending on the eGPU via this menu bar option”

This is what made the eGPU unworkable for me. When you eject the GPU using the menubar item, it will close and reopen many of your open applications. It’s too disruptive for someone who moves their computer multiple times a day.

The last dual-GPU Mac I used was a 2012 Retina, and I don’t remember it being that precious about switching between the iGPU and the dGPU. Sometimes you had to quit one or two apps to get it to switch back, but never most of them.

The problem with Thunderbolt GPU enclosures is they often cost more than the GPU you’re putting inside of it.

@remmah How long do you think they’ll last? Can you get one enclosure and keep it through multiple computer and GPU upgrades? Or are they, practically speaking, single use?

I‘ve been using Thunderbolt2 enclosure with external power source and 2014 MBP for the past 2 years. Works pretty great with modern games and VR. If you use Thunderbolt3 enclosure you’re pretty much set for a few years. There’s no new standard on the horizon and the performance/bandwidth penalty is not an issue.

Ghost Quartz

@Michael I don’t see why you couldn’t keep using the enclosure. Although PCIe 4.0 is beginning to enter the market [1], I believe PCIe 4.0 cards will be backward compatible with PCIe 3.0 slots [2], and considering Thunderbolt 3 barely provides 4-lanes of PCIe 3.0 bandwidth [3], it doesn’t seem like a future PCIe 4.0 enclosure would provide any practical bandwidth benefits anyways. That said, you may want to do some research into whether your use-cases will be bandwidth constrained, but I think gaming and desktop use ought to be fine.

I have no idea what the story with Thunderbolt 4 is, but I imagine it’d maintain backwards compatibility with Thunderbolt 3 peripherals as well.

Another thing to consider is whether the enclosure can fill your needs as a Thunderbolt dock; in addition to display output, many provide USB-PD, and some also provide USB A ports and Ethernet. Of course, before buying an enclosure with additional I/O, I’d research macOS compatibility, and whether there are performance issues with the USB-A or Ethernet ports (which I believe can arise from everything sharing a single Thunderbolt controller in the enclosure [4]).

[1] See AMD’s X570 chipset
[2] https://www.tomshardware.com/news/what-we-know-about-pcie4,39063.html
[3] https://en.wikipedia.org/wiki/Thunderbolt_(interface)#Thunderbolt_3
[4] See https://egpu.io

Ghost Quartz

To clarify that last point, I think some enclosures use dual Thunderbolt controllers to avoid performance issues with USB peripherals. Or something like that…

@Ghost Thanks. This is not for me personally; I’m just curious. I’m not asking so much about backwards compatibility as whether an older enclosure would constrain the next generation(s) of cards. I remember concerns about latency when Apple first announced eGPU support, and it’s not clear to me whether those were unfounded or might be more of a problem in the future.

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