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The Dell OptiMac Big Sur/OpenCore Thread

trs96

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I wasn't sure if there was a way I could check before getting into changing it.
First, make sure you flashed the latest BIOS for your Optiplex if you haven't done that.

It's all in the guide https://www.tonymacx86.com/threads/the-dell-optimac-big-sur-opencore-thread.302383/#post-2165113 you need to boot from the USB into a modified Grub Shell to determine the current setting.

Type this after the prompt (in orange) press return and it will tell you what the offset is currently.

Screen_Shot_23.png


If 0x263 is not 0x2 it's not set to 64MB DVMT. That simple.

1609963344635.png
 
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Dell Optiplex 9020 SFF
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i5-4590
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First, make sure you flashed the latest BIOS for your Optiplex if you haven't done that.

It's all in the guide https://www.tonymacx86.com/threads/the-dell-optimac-big-sur-opencore-thread.302383/#post-2165113 you need to boot from the USB into a modified Grub Shell to determine the current setting.

Type this after the prompt (in orange) press return and it will tell you what the offset is currently.

View attachment 504070

If 0x263 is not 0x2 it's not set to 64MB DVMT. That simple.

View attachment 504069
I'm on A25 so I'm good there. I am having an issue editing my plist with ProperTree to add the necessary steps to Misc/Tools. I am trying with PlistEdit Pro so I will try to boot into the modified grub shell to check on this stuff. Wish me luck!
 
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Motherboard
Dell Optiplex 9020 SFF
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i5-4590
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HD4600 2048MB / Nvidia GeForce 710
Mac
  1. iMac
Tried using his latest. No change. Who knows. Thank you again though.
 

trs96

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Tried using his latest. No change. Who knows. Thank you again though.
You're welcome. 4K/60 will work with Catalina if it's a must have for you. Some have reported that 4K wasn't working at all in the Big Sur Betas. It may still not be fixed yet for Big Sur. I had thought it would have been by now but obviously it isn't. Acidanthera will likely figure out and resolve the problem eventually. Maybe by 11.2 or 11.3.
 
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trs96

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Same issue !
It would be best to follow the USB for beginners guide to sort this out.

 
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It would be best to follow the USB for beginners guide to sort this out.

Thanks i cant find the issue. I think AHCI?

PXL_20210108_165642613.jpg
 
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trs96

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Joined
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Is your problem with the initial install or with USB 3.0 ports. Not clear to me.
When i disable USB 3.0 Ports i can go to install screen.
 
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