Dear Chris,

thank you for the advice. I've attempted to use the Metal version of MRIcroGL but unfortunately it does not seem to be able to load the 4D NIFTI either in my MacPro 2019.

I will use MRIcroGL in another machine while I wait for an update from Apple (though I am not holding my breath :-)

Cheers,

E.

Originally posted by Chris Rorden:

I can not replicate this on any of my machines. It appears that the computer that is causing issues is a MacPro 7,1 from 2019 which were only offered with AMD Radeon graphics cards https://support.apple.com/en-us/102887

Macs with AMD graphics cards depend on Apple drivers, and these have not seen much support, especially as Apple has moved to manufacturing their graphics cards in house. I think it is telling that the graphics driver reports "ATI Technologies Inc.; OpenGL = 2.1", as AMD acquired ATI in 2006!

https://en.wikipedia.org/wiki/ATI_Technologies

Once upon a time, ATI cards only supported power of two textures, and your data is not a power of two: 207x246x215. 

You might want to see if the version of MRIcroGL that uses Metal directly instead of OpenGL (MRIcroMTLforMacOS_Sonoma) works:

https://github.com/rordenlab/MRIcroGL/releases

If this fails, I am afraid you are at the mercy of Apple's driver team, that has little incentive to support this old but capable hardware.