devkhaled Posted May 30, 2021 Share Posted May 30, 2021 hi everyone i'm have install Big Sur on dell precision 7510 i7 6820 HQ with intel hd 530 everything work fine except the monitor i have 32 Samsung 4k monitor link by HDMI in my dell the problem : there are lag in monitor I don't know what is causing the lag ? i can't fix it , any help ? thanks Link to comment Share on other sites More sharing options...
Moderators Jake Lo Posted May 30, 2021 Moderators Share Posted May 30, 2021 Post IOReg file using IOREgistryExporer.app v2.1, not 3.0+ with the HDMI monitor connected Link to comment Share on other sites More sharing options...
devkhaled Posted May 30, 2021 Author Share Posted May 30, 2021 here you are Khaled.ioreg Link to comment Share on other sites More sharing options...
Moderators Jake Lo Posted May 30, 2021 Moderators Share Posted May 30, 2021 Looks like files from my 7510 guide. I needed to add them to enable graphics on the USB-C port. I haven't tested the HDMI on a 4K display before, perhaps might need to raise the DVMT-Pre-alloc value Link to comment Share on other sites More sharing options...
devkhaled Posted May 30, 2021 Author Share Posted May 30, 2021 how i can raise the DVMT-Pre-alloc value ? thanks Link to comment Share on other sites More sharing options...
Moderators Jake Lo Posted May 30, 2021 Moderators Share Posted May 30, 2021 In my files, I've included a DVMT script. Modify the grub.cfg with textedit Change setup_var 0x432 0x3 to setup_var 0x432 0x4 Save the file Go to your BIOS, add new boot Option. Call it DVMT or whatever, point to /EFI/Boot/DVMT/bootx64.efi On boot, press 12 and select the new boot option DVMT On the Grub Shell GUI, select the 1st option This will disable the dGPU, change DMVT to 128MB, and enable switchable graphics This will reboot the computer automatically to make the changes. Boot to MacOS and test. With the changes, you may disable these in the Config file. Add # infront incase you may want to re-enable and not have to re-add framebuffer-fbmem framebuffer-stolenmem Link to comment Share on other sites More sharing options...
devkhaled Posted June 2, 2021 Author Share Posted June 2, 2021 sorry for late i go to your guide download the EFI , copy the file to my EFI and change the values of grub.cfg then i add new boot option : DVMT and point to /EFI/Boot/DVMT/bootx64.efi when i boot and choase DVMT , give a black screen and 3 options about F1 F2 F12 Link to comment Share on other sites More sharing options...
Moderators Jake Lo Posted June 2, 2021 Moderators Share Posted June 2, 2021 you can skip this, I tested and it didn't work. I'll test other option and report back Link to comment Share on other sites More sharing options...
Moderators Jake Lo Posted June 2, 2021 Moderators Share Posted June 2, 2021 this is what I have read You can do 4K @24/25/30Hz with HDMI 1.4 but the interface does not provide enough bandwidth for 4K @60Hz. To get enough bandwidth for 4K @60Hz you need HDMI 2.0 or better. The 7510 has HDMI 1.4, so try lowering the frequency might help with the lagging. Or use Display port if available. Link to comment Share on other sites More sharing options...
devkhaled Posted June 2, 2021 Author Share Posted June 2, 2021 ok , i tried now to low the HDMI to 1.4 from 2.0 of my monitor setting and the lag still happen i wonder about the lag , because i used to install Big Sur on dell latitude e6540 and there are no lag is the HDMI in latitude was higher than the 7510 ? and if i use display port , is it will look like the HDMI in resolutions ? Link to comment Share on other sites More sharing options...
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