GPU and CPU rendering on MacBookPro M2 ProMax

I have the latest Apple MacBook with Apple silicon, 96GB of RAM running Ventura. I am using the most recent build of Slicer for Mac from 2023-4-25. My fairly large data sets are rendering well, though slowly, using the CPU, but when I swap to GPU the volume is a uniform prism of color. Here is an example data set of a clingfish.

I expect the answer is that Apple silicon is just not working well with Slicer, but if someone has a workaround it would be great.

@jcfr @pieper this the screenshot @Adam_Summers sent me earlier, if it helps…

CPU rendering

GPU rendering.

Thanks for sharing the data. I could use GPU rendering on a mac pro, but on a mac book air m2 I got this error:

[VTK] Invalid texture dimensions [447, 318, 2308]

[FD] UNSUPPORTED (log once): POSSIBLE ISSUE: unit 1 GLD_TEXTURE_INDEX_3D is unloadable and bound to sampler type (Float) - using zero texture because texture unloadable

so it must be a hardware or driver limit, probably to 2048 max dimension

I used CropVolume with a 1.5x multiplier on the spacing and then GPU rendering worked on the m2 machine:


Dear Steve, thanks so much for identifying the issue. You have given me a path to a work around. I really appreciate it.


This is an unfortunate limitation, particularly if this is true for the top of the line M2 macbook pro @Fishguy has. I don’t have this problem on my 2018 intel macbook pro.

Do you know if there is a way to report this to apple? I am concerned because a lot of biology folks use Slicer on Mac, and that’s a limitation we can’t do much.

Just to follow up. Steve has found the issue. More than 2048 slices and the GPU won’t work. I have tested this with 5 data sets that were not working, and by cutting down the number of slices they work just fine. The InputStack module in SlicerMorph (which I think Steve wrote) has a ‘Skip Slices’ option that allows you to tune the total slices in the Z direction. That is a work around until Apple gets itself in order on this.

Thanks a lot.


From what I can tell this is a hardware limit on Apple GPUs. This document says that all the apple GPUs, including the “Metal 3” in the M2 have a max size of 2048 in all dimensions. It’s hard to know if they will relax this in the future. For. now I’m afraid downsampling is the best option.

@Adam_Summers if skipping slices give you okay image quality then that’s a good workaround. Using CropVolume to downsample a larger volume will be less lossy, but more time consuming of course.