SMBios 19.x - iMacs 2019

[Blindedbythelights]

Ok got it

@pastrychef sorry to bother you again. I managed to capture a video showing something that might help troubleshoot further. The issue is I get strange glitching sometimes when playing videos via VLC/QT or via Quicklook (QT?). However I can play the exact same video that was glitching in audio software called Reaper via its video player and there's no glitching. You can set the video decoder in reaper to be either VLC/QT or FFMPEG. It's currently set to VLC. So why would it glitch via the VLC app in Mojave but not when being played in some audio software using the decoder? Does this give any clues?

 

[pastrychef]

@pastrychef sorry to bother you again. I managed to capture a video showing something that might help troubleshoot further. The issue is I get strange glitching sometimes when playing videos via VLC/QT or via Quicklook (QT?). However I can play the exact same video that was glitching in audio software called Reaper via its video player and there's no glitching. You can set the video decoder in reaper to be either VLC/QT or FFMPEG. It's currently set to VLC. So why would it glitch via the VLC app in Mojave but not when being played in some audio software using the decoder? Does this give any clues?

I have no idea. It doesn't make any sense to me...

 

[Blindedbythelights]

I have no idea. It doesn't make any sense to me...

Odd isn't it. Someone has suggested to try the iMacpro 1,1 smbios. I think I will since this glitch stuff seems to happen when there is some element of igpu involved. Annoying thing about the change is it will reset some of my software authorisations.

 

[Blindedbythelights]

Odd isn't it. Someone has suggested to try the iMacpro 1,1 smbios. I think I will since this glitch stuff seems to happen when there is some element of igpu involved. Annoying thing about the change is it will reset some of my software authorisations.

With igpu off in bios and iMac Pro 1,1 SMBIOS the glitching seems to be fixed! Might be speaking too soon but seems to be good so far. I'm also seeing full hardware acceleration via the RX580.

 

[pastrychef]

With igpu off in bios and iMac Pro 1,1 SMBIOS the glitching seems to be fixed! Might be speaking too soon but seems to be good so far. I'm also seeing full hardware acceleration via the RX580.

iMacPro1,1 works good. I've been using it for a little while now and everything has been smooth.

 

[Blindedbythelights]

iMacPro1,1 works good. I've been using it for a little while now and everything has been smooth.

I didn't know you were using it, thought you were on 19,1. You also have a Radeon VII!!! nice. I'd love one but really can't justify it hah.

 

[pastrychef]

I didn't know you were using it, thought you were on 19,1. You also have a Radeon VII!!! nice. I'd love one but really can't justify it hah.

For me, iMacPro1,1 works better than iMac19,1.

 

[Shiitaki]

Anyone tried this or can confirm the source that it's no longer needed? @ModMike

I went through and tried removing my boot flags one at time to see if I really needed it. Removing Dart=0 caused no problem. In my research it should disable vt-d, which I always turn off in the bios anyway, so it makes sense I don't need it. Just in case someone is curious, vt-d is a virtualization feature, but is an advanced one for type 1 hypervisors which are operating systems that only run VMs, so has no effect on Type 2 hypervisors like Parallels and Fusion. By default real Macs all have CPU virtualization features enabled. The vt-d is a chipset feature as it virtualizes the I/O addresses of hardware devices between the physical world and VMs.

 

[pastrychef]

I went through and tried removing my boot flags one at time to see if I really needed it. Removing Dart=0 caused no problem. In my research it should disable vt-d, which I always turn off in the bios anyway, so it makes sense I don't need it. Just in case someone is curious, vt-d is a virtualization feature, but is an advanced one for type 1 hypervisors which are operating systems that only run VMs, so has no effect on Type 2 hypervisors like Parallels and Fusion. By default real Macs all have CPU virtualization features enabled. The vt-d is a chipset feature as it virtualizes the I/O addresses of hardware devices between the physical world and VMs.

VT-d is an incredibly powerful feature that allows for direct I/O to devices by the guest operating systems. This allows, for example, direct pass through of GPU to the guest operating system thus allowing full speed GPU acceleration. Envision an i9-9900K system with two video cards running two operating systems at the same time each with 4 cores/8 threads and its own GPU.

ESXi, Proxmox, and Qemu in Linux can take advantage of this. As far as I know, macOS does not support VT-d.

Personally, being forced to keep VT-d disabled might be a deal breaker for me.

 

[Blindedbythelights]

I went through and tried removing my boot flags one at time to see if I really needed it. Removing Dart=0 caused no problem. In my research it should disable vt-d, which I always turn off in the bios anyway, so it makes sense I don't need it. Just in case someone is curious, vt-d is a virtualization feature, but is an advanced one for type 1 hypervisors which are operating systems that only run VMs, so has no effect on Type 2 hypervisors like Parallels and Fusion. By default real Macs all have CPU virtualization features enabled. The vt-d is a chipset feature as it virtualizes the I/O addresses of hardware devices between the physical world and VMs.

Ok thanks I have disabled vt-d in bios so makes sense to remove from my config since I don't need it.