MWorks and Mojave

May 13, 2019 Posted by Christopher Stawarz


If you’re thinking about upgrading to macOS Mojave (10.14) (perhaps to take advantage of the new Dark Mode support in MWorks 0.9), here are a few things to consider first.

Issue with multiple displays

Update (2019/8/12): The issue described below appears to be fixed in macOS 10.14.6. I no longer observe the telltale stuttering on either of my Mojave systems. Reportedly, the issue is absent in the macOS Catalina beta as well.

macOS Mojave appears to have trouble driving multiple displays simultaneously. The issue manifests as visible stuttering in on-screen graphics. In MWorks, these stutters are accompanied by bouts of “Skipped xx display refresh cycles” messages. In my experience, the stuttering episodes occur cyclically, with 1-2 minutes of stuttering followed by 5-10 minutes of normal graphics performance. The only remedy is to reduce the total number of connected displays (both internal and external) to one.

I have observed this issue on a late-2013 Mac Pro and a 2018 Mac mini, both running macOS 10.14.4 (though it may affect earlier 10.14 releases, too). I have not observed it on earlier macOS versions. Also, this issue is not present on iOS.

Support for 2010/2012 Mac Pro

Mojave is the first macOS release to require a graphics card that supports Metal, Apple’s modern graphics programming framework. Most Mac computers released since 2012 support Metal. However, the stock graphics cards in the 2010/2012 Mac Pro (i.e. the last “cheese grater” Mac Pro) do not.

Fortunately, you can make a 2010/2012 Mac Pro compatible with Mojave by upgrading its graphics card. Apple provides a list of supported graphics cards, any of which should be fine for use with MWorks. Even if you don’t plan to switch to Mojave any time soon, this upgrade may still be worthwhile as a future-proofing step. (I recently installed an MSI Gaming Radeon RX 560 128-bit 4GB GDRR5 in one of my MWorks test systems, a 2010 Mac Pro running macOS 10.13.6, and have been very happy with its performance.)