[Solved] [SCRIPT] PurgeWrangler: AMD + NVIDIA eGPUs for all Thunderbolt Macs  

Posted by: @_photoguy_

Posted by: @dominicperry

[Sorry to re-post, but getting no replies at all in the Thunderbolt/Mac forum:]

If I use a USB audio interface, all is fine, so it seems to be a TB problem, rather than a CoreAudio problem.

At 44.1KHz, the crackles are minor - but still constant - several every second. At 96KHz, it's like listening through static.

Does anyone have any suggestions for fixing this please?

Dominic

I don't think that's a TB issue, most probably it's a grounding issue.

You see the data is digital, so no amount of interference on the data bus is going to be able to cause what you describe because either it's not enough to disrupt the data, or if it is too much your entire device would not work. But both devices work, so the information (audio stream) reaches the destination correctly.

Until the signal is digital, there is no noise, so when can the signal be affected by noise? When it becomes analog again: the DAC (Digital to Analog Converter) uses ground as a reference, and it is possible that this ground is affected by other devices on the bus.

Given the fact your audio box works good without the sonnet, I'd suppose it's something in the sonnet that makes the ground really dirty. Could be the sonnet itself or the video card in it.
Maybe you can check if the sonnet is correctly earthed? Mine has a 3 poles plug, so make sure earthing is connected.
Unfortunately I don't see what else you can do about it without some more complicated equipment (oscilloscope at least) and undertaking (opening up your audio box and checking the ground scheme of the DAC and the voltage levels)

Thanks for the comments. The problem is only during playback - it's not interference. And it only happens when the monitor is connected to the HDMI port of the 5700 XT - if I use the MacBook HDMI port, it doesn't happen, even though the Sonnet and 5700 XT are active and running (and still boost my graphics performance to a degree). Unfortunately, I built this with the intention of using a Dell 5120x1440 screen, which needs to be connected to the DP port of the 5700 XT, so it's not a real solution. 

So, the problem only occurs if I'm both (a) using the HDMI port on the eGPU and (b) playing back in iTunes, Pro Tools, YouTube etc. As soon as I stop playback, the crackle stops, so it isn't an earthing or interference problem. 

Dominic

Posted by: @_photoguy_

Bad previous experience and the fact that my setup is not officially supported by Apple, so it is possible they break it at any time. And I'm really depending on it.

Fair enough 😛 - macOS can be naughty. Did SMC reset not work? Consider rebuilding kext cache and rebooting:

sudo kextcache -i /

@dominicperry interesting that the issue only occurs for you when using eGPU output. I faced an issue with a USB DAC/AMP connected to eGPU's USB port. Audio would lag/drop basically, and there seemed to be a bit of a correlation with GPU load. This was on a TB3 mac. On top of that, macOS has previously been riddled with audio problems - I've had many over the years, including:

• Crackling audio
• LR balance change without notice
• Outright no audio output

I presume the Apollo comes with drivers/plugins? Could you reset/reinstall those? Also consider resetting CoreAudio and macOS audio drivers: https://superuser.com/questions/647396/reload-mac-audio-drivers-without-rebooting

Posted by: @mac_editor

Posted by: @_photoguy_

Bad previous experience and the fact that my setup is not officially supported by Apple, so it is possible they break it at any time. And I'm really depending on it.

Fair enough 😛 - macOS can be naughty. Did SMC reset not work? Consider rebuilding kext cache and rebooting:

sudo kextcache -i /

Yes, I nailed it down to some issues with SMC, Nvram not having anything to do with it.
Still don't trust Apple though ;P

This is my configuration:
Mac mini (Late 2012) i5 2,5GHz | Sonnet 350 + Sapphire NITRO RX 480 8GB | 16GB RAM | 1TB SSD
TB1 enabled with purge-wrangler

Can I upgrade to Catalina, or are there any problems with this configuration?

I happen to have some random freezes with Mojave 10.14.6.

I wanted to understand if I could improve performance and solve that problem.

Thanks in advance!

Supplemental 10.15.4 update is out, has any of you already installed? 

Can't lose eGPU atm, so if anyone has already installed and can confirm everything is still good that would be great. 

Thanks!

@jeroen-van-keulen, Still working 😉 

Firstly thanks for all the effort and support for this tool. I have a Late 2013 MBP 15" (Intel Iris Pro), Aorus Gaming Box (AGB) 1070 rev 1.0 so TB3->TB2 (Apple cable 2m) and a fresh install of High Sierra 10.13.6.

I installed purge-wrangler with instructions from the wiki and enabled Ti82 as the eGPU was not detected automatically. (there is a long pause in the countdown timer when I connect the device)

>> System Status

Ti82 Devices      Enabled

TB1/2 AMD eGPUs   Disabled

Legacy AMD eGPUs  Disabled

NVIDIA eGPUs      Enabled

Web Drivers       Patched

I see the device in the Thunderbolt tab in System Report but not in the Graphics tab or the main About page.

I have an external monitor connected via the HDMI port on AGB. I tried several reboots with connected/hot plug, log outs, multiple re-installs of purge-wrangler and I see the fan running on AGB. Please let me know if I can provide any other info.

Would appreciate your help on this.

I have been going nuts -- I have the following setup:

• MacBook Pro 2019 16" with Core i9 and Radeon RX 5500M 4GB dGPU 
• Razer Core X w/stock TB3 cable
• Nvidia GTX Titan Black 6GB GPU 

1. When I use Purge-Wrangler and reboot; the system freezes on the Apple Logo. The system fans then spin up fast and the machine shuts down. 
2. If I boot without the eGPU plugged in, then plug in at login screen, the eGPU is detected and it "pretends" the login screen is being output to the monitor, but it is only a black display on the external monitor (using HDMI AND DisplayPort)
3. If I boot, login, plug in eGPU, the system freezes, then reboots about 50% of the time. The other 50% of the time, its fine. I then Go to "About this Mac" and see the Nvidia GTX Titan Black is listed as a GPU, but am unable to use it to output to another display. 

I have tried the command pmset -a gpuswitch 0 command, which seems to be input correctly... but nothing happens. I'm at a loss. 

@network_noob534, https://github.com/mayankk2308/purge-wrangler/issues/48

@_photoguy_, I see you have to use it also. After every update of Catalina I have to go in recovery and rebuild kext cache. Quite a pain in the butt. At the latest update it did not wanted to finish updating before I rebuild the cache for which I had to risk killing the mac in the last booting step, going into recovery, fixing kexts and rebooting to finish the update... Here is the procedure for recovery kext rebuilding.

Boot in Recovery and open terminal. Skip sudo in recovery mode.

csrutil disable 

Reboot and log back into recovery

Disable Gatekeeper and mount file system in read/write mode:

sudo spctl --master-disable

sudo mount -uw /

sudo killall Finder (skip in recovery mode)

Repair permissions & rebuild kernel cache:

sudo chown -v -R root:wheel /Volumes/my hdd/System/Library/Extensions

sudo touch /Volumes/my hdd/System/Library/Extensions

sudo chmod -v -R 755 /Volumes/my hdd/Library/Extensions

sudo chown -v -R root:wheel /Volumes/my hdd/Library/Extensions

sudo touch /Volumes/my hdd/Library/Extensions

sudo kextcache -i /Volumes/my hdd/