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Changing 0xAE by 0xBF make loop booting
So, just to be clear 0xBF gives you reboot loop? And what about 0xAE? The backup registry attached is different from the screenshot you provided:
1682240124510.png

device-id here is 0xEF not 0xAE.
 
You can delete altogether the device-id section in the SSDT:
1682241742752.png


macOS will try to match the driver automatically.
 
So, just to be clear 0xBF gives you reboot loop? And what about 0xAE? The backup registry attached is different from the screenshot you provided:
View attachment 2192406
device-id here is 0xEF not 0xAE.
0xAE give me normal boot but very slow display and no acceleration
0xBF give me reloop boot

The backup registry you show is yours ;)
Capture d’écran 2023-04-23 à 13.49.25.png


I tried now to change the SSDT
 
The backup registry you show is yours ;)
Still sleeping :). Ok, so the SSDT worked, but it does not like so much 0xAE and 0xBF does not let it boot. How about removing the device-id from the SSDT? You need to find a device-id match which will load the driver. Try this SSDT
 

Attachments

  • 6900XT.zip
    989 bytes · Views: 88
Still sleeping :). Ok, so the SSDT worked, but it does not like so much 0xAE and 0xBF does not let it boot. How about removing the device-id from the SSDT? You need to find a device-id match which will load the driver. Try this SSDT
I try now with SSDT without device-id...
Next i try the last one
 
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Try this one.
  • Under NVRAM -> Add -> 7C436110-AB2A-4BBB-A880-FE41995C9F82 -> boot-args, append the boot arg agdpmod=pikera -radcodec
    • -radcodec: Used for allowing officially unsupported AMD GPUs (spoofed) to use the Hardware Video Encoder
    • NVRAM Section
  • Save the file
 

Attachments

  • 6900XT.zip
    821 bytes · Views: 87
Last edited:
Try this one.
Good morning Startergo,
I do all the change but always no results...sorry
Please find attached :
  • Last config.plist used
  • Last IO Registry backup
  • 4 screen captures
🤞
GeekBench 5.png
PCI.png
Video Card.png
Videoproc.png
 

Attachments

  • MPNE293OX_v5.zip
    7.3 MB · Views: 77
  • config.plist.zip
    6.3 KB · Views: 73
@olixsm it is weird, but the same part number comes with 2 different vBioses:
1682368103768.png


73BF is the supported vBios and 73AF is the unsupported one. Essentially it is a modded vBios and theoretically the 73BF vBios should work for your card. The biggest differences are the top end of the memory frequency, some thermal limits and the memory clock. You can try flashing this vBios (obviously after applying the fixROM):
Your vBios is here:
 
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@olixsm it is weird, but the same part number comes with 2 different vBioses:
View attachment 2193114

73BF is the supported vBios and 73AF is the unsupported one. Essentially it is a modded vBios and theoretically the 73BF vBios should work for your card. The biggest differences are the top end of the memory frequency, some thermal limits and the memory clock. You can try flashing this vBios (obviously after applying the fixROM):
Your vBios is here:
[SOLVED] Where i can find informations on the picture ? what software to use ?
 
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Can I use a flashing tool (the one I used to flash my titon ridge thunderbolt card ) to flash a 6800? I don't know anyone with a tower pc. I do have an all in one windows pc..
 
Can I use a flashing tool (the one I used to flash my titon ridge thunderbolt card ) to flash a 6800? I don't know anyone with a tower pc. I do have an all in one windows pc..
You may be able to, but you have to de-solder the chip. The in-curcuit flashers are expensive.
 
Ok. Is there somewhere I can have it done?
The cheapest way is probably to get a cheap PC from your local recycling store. You can also get a hot air station to desolder and solder back the chip like this one
https://www.amazon.com/PROSTORMER-temperature-Efficiency-212-932°F-Electronics/dp/B08VNYPL7H/ref=mp_s_a_1_4?crid=2NZARYP2RTUKC&keywords=soldering+heat+gun&qid=1682506724&sprefix=soldering+heat+gun%2Caps%2C338&sr=8-4
 
Hum... I never thought of going to a rec. center or pawn shop. I guess it doesn't have to be a crazy pc then.
I recently purchased a cMP5,1 with a motherboard, CPU tray old video card and a power supply all for 35 bucks. Before I went to the recycling store I called and asked if they had an empty case. The guy said he will sell me one for 35. 15 minutes later I was in the store and he only managed to take out the RAM and the HDD. He did not bother with the rest. But there are dirt cheap PC’s and Macs in those stores.
 
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Hum... I never thought of going to a rec. center or pawn shop. I guess it doesn't have to be a crazy pc then.

No it doesn't, just any PC with Windows (where you have admin access) and an available PCIe slot. Syncretic's flash takes less than 5 mins, and once it's done, (assuming you already had Pixlas mod done and have the right changes done to your OC config file) you simply throw the GPU into the cMP and voila.
 
No it doesn't, just any PC with Windows (where you have admin access) and an available PCIe slot. Syncretic's flash takes less than 5 mins, and once it's done, (assuming you already had Pixlas mod done and have the right changes done to your OC config file) you simply throw the GPU into the cMP and voila.
ok.
 
No it doesn't, just any PC with Windows (where you have admin access) and an available PCIe slot.
Hmm, doen't it have to be at least UEFI and not legacy bios?

If you have access to the chip (meaning you went trough the mess of removing this monster of a carbon glued cooler of the 6800/6900/xt), also a USB-hardware programmer like the well known and cheap CH341A will do. The chip does not have to be desoldered to get it programmed!
 
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Hmm, doen't it have to be at least UEFI and not legacy bios?

If you have access to the chip (meaning you went trough the mess of removing this monster of a carbon glued cooler of the 6800/6900/xt), also a USB-hardware programmer like the well known and cheap CH341A will do. The chip does not have to be desoldered to get it programmed!
For me it is easier to desolder the chip than remove the cooler and the rest of the circuit.
 
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