1. AVX2 and Ventura:
You may check this
link about the current situation.
For all of who have installed Ventura on any supported/unsupported devices you may use this
method to check for AVX2 instructions hidden in any executables or libs. Unfortunately is is not that easy to access binaries from the kernel extensions any longer since they are not stored on disk but hidden in a big cache.
The AMDRadeonX4000GLDriver.bundle now has
AVX2 code included. It was used on Monterey for all AMD GCN 1-4 AMD dGPU for acceleration.
Same applies to the AMD libs used in the OpenCL.frameworks, which explains why OpenCL is broken on pre (late 2013) Macs.
2. Booting macOS 13 on unsupported pre Haswell devices
You may ask the guys posting their
success here about
crashes of numerous components starting with the setup screen, login screen, window server. The spoiler on the first post has the title "List of officially unsupported machines that have shown Ventura
booting ability to some degree".
I know, the human cerebrum gets tricked and fooled easily starting to ignore facts when the brainstem comes up with hopes and wishes. But this is not about believing, it is about stating simple undeniable facts.
3. Some experiences using the same Ventura installation on different iMacs:
The older the CPU gets the more crashes I got using the same SSD with beta 1 to boot from and the same dGPU (supported, but not accelerated metal Polaris dGPU due to lacking AVX2 support) in different iMacs from 2009 to 2011:
- iMac12,2 Mid 2011 Sandy Bridge CPU (WindowServer crashing, apps like Maps not working, etc. ),
- iMac11,3 Mid 2010 Lynnfield CPU (more crashes, setup, login, window server, had to run setup on 2011 at the very end)
- iMac10,1 Late 2009 Wolfdale CPU (many more crashes, sometimes booting not possible, meta stable situation).
You may extrapolate from this to other older pre 2010 systems.