Intel UHD (bad for MAME) and macOS Big Sur 11.1 first impressions

As already anticipated in this post, probably any Intel Macs with Intel UHD Graphics are a quite bad choice for MAME. Here is new proof with the probably very latest Intel Mac mini, a machine that I otherwise very much like. 

But as also barefeats.com explain here, these Mac minis 'scream for an eGPU' when it comes to gaming and other GPU-intensive tasks.

This Mac mini has it all - except for the GPU.

For all Mac Users out there that are struggling with MAME performance - just check your GPU and forget about the rest. If you have some Intel UHD Graphics installed, you already know the culprit. Shaders will then not perform nicely, and also Bezel Artwork. So here is some numbers with identical MAME versions and identical ROM files.

Terminal command: 

./mame64 -video bgfx -str 60 -noafs -bgfx_screen_chains crt-geom -bgfx_backend metal -noreadconfig -nosleep -nothrottle -lowlatency 1942

Disastrous Performance Difference

While I expected degraded performance, this performance drop came unexpected. The GPU in my aging iMac, an NVidia GTX 780M with 4GB, is nothing more than a rather powerful notebook GPU. But still you can see how incredible the impact of a low end GPU can be on MAME. And I had already similar experiences on a 2012 MacBook Pro with Intel UHD GPU inside.

macOS Big Sur Performance Improvements come to the rescue (a bit)

Now that macOS Big Sur 11.1 is out, I saw no reason for further delaying this upgrade from Catalina (my iMac no longer qualifies for this one). And there actually is a very pleasant surprise - a surge in MAME performance on my Mac mini.

I also checked both the Metal and the OpenGL Backend of BGFX - this is the OpenGL command:

./mame64 -video bgfx -str 60 -noafs -bgfx_screen_chains crt-geom -bgfx_backend opengl -noreadconfig -nosleep -nothrottle -lowlatency 1942

Compared to Catalina with identical MAME version and ROMs, there is a quite remarkable surge in performance. At the same time it is interesting that there is virtually no difference between the Metal backend and the OpenGL backend of BGFX. Considering that OpenGL is a Legacy backend in MacOS for quite some time now, I did not expect this. 

Talking in more practical terms: When playing the games, the surge in performance probably adds the necessary performance hike to always stay on the safe side. I also tried all these games briefly, and at 100% speed, they just feel stable. 

This is why in the end, I can be happy with my current MAME setup in Big Sur, even on a rather low performer Intel UHD GPU. But this will never become a decent MAME machine.

And how was the upgrade to macOS Big Sur 11.1?

This upgrade really shined. There is really nothing to report so far. I did this upgrade today in the morning (from a fully updated Catalina install), and it ran through without any attendance being required. MAME just works, Homebrew required a minor upgrade, and RetroArch also works like under Catalina. Again, really nothing to report here, everything just works. But nothing else to be expected in case of a rather recent Mac mini purchased in 2020.

What about OpenEmu?

OpenEmu has just been upgraded to version 2.3, and it runs very well on my iMac Late 2013 (see this post). For my Mac mini, MAME standalone seems to be the better solution performance-wise. Any more serious shader, such as CRT-GEOM, is too much to handle.

Retroarch suits better to Low Performers

With Retroarch, the situation is a bit different. The OpenGL version is a good contender, while the Metal version of Retroarch does not seem to work since Catalina. While the CRT-GEOM shader also is too much, the CRT-Easymode shader fits nicely and provides good performance. The Runahead feature also works decently, so there is some competition coming from Retroarch on lower-performing Macs. This is no surprise since Retroarch is also the core of the entire Retropie project.