[HELP] How to set DVMT-prealloc to 96MB or 128MB in BIOS

[sebasriostod]

I'm currently hackintoshing a Dell 7559 UHD variation. I have El Capitan 11.5 Installed, booting without graphics (just 31MB VRAM - Intel 'Unknown') and I have also patched IOKit framework but I don't know how to set DVMT-prealloc in this laptop.

Please help so If I can get this done, I'll create a guide for this laptop variation

 

[RehabMan]

I'm currently hackintoshing a Dell 7559 UHD variation. I have El Capitan 11.5 Installed, booting without graphics (just 31MB VRAM - Intel 'Unknown') and I have also patched IOKit framework but I don't know how to set DVMT-prealloc in this laptop.

Please help so If I can get this done, I'll create a guide for this laptop variation

Not a desktop. Moved to laptop support.

See FAQ: http://www.tonymacx86.com/el-capita...faq-read-first-laptop-frequent-questions.html

 

[sebasriostod]

the only thing that I've found on the FAQ was this:

Q. Are QHD+/UHD laptop displays supported?

Requirements for QHD+/UHD displays:
- patched IOKit framework (to remove pixel clock limitations)
- DVMT-prealloc set to 96MB or 128MB in BIOS
- Haswell: ig-platform-id 0xa2e0008
- Haswell: framebuffer configuration for 0xa2e0008 patched to match DVMT-prealloc value (Broadwell determines BIOS size dynamically)
- "normal" requirements for Haswell/Broadwell systems

Refer to this post as an example: http://www.tonymacx86.com/yosemite-...novo-yoga-2-pro-hd4400-qhd-qe-ci-working.html

For patching IOKit, clear instructions for using the-darkvoid's XPS9530.sh script are in the Y50 guide: http://www.tonymacx86.com/el-capita...-y50-uhd-1080p-using-clover-uefi-10-11-a.html

IMPORTANT!: Contrary to many of the guides you will read, Windows is NOT a valid way to determine what DVMT-prealloc is set to. There is no correlation, especially with Windows 10

I've already patched IOKit framework but I have no idea how to change the DVMT-prealloc size in BIOS since there is no such option... please help

 

[RehabMan]

I've already patched IOKit framework but I have no idea how to change the DVMT-prealloc size in BIOS since there is no such option... please help

There are links in the FAQ for guides that discuss changing DVMT-prealloc via a special UEFI shell.

 

[sebasriostod]

There are links in the FAQ for guides that discuss changing DVMT-prealloc via a special UEFI shell.

I've read a warning in a DELL Guide (here) about editing the DVMT Pre-allocation using the EFI Shell

Warning for 4k / UHD screen owners:
Do not use the EFI shell to to edit the DVMT Pre-allocation for getting your screen to work. This bricked a user's machine already. Instead, make use of a patch explained in a lower section of this guide

http://www.tonymacx86.com/threads/guide-dell-xps-15-9550-skylake-gtx960m-ssd-via-clover-uefi.192598/

 

[RehabMan]

I've read a warning in a DELL Guide (here) about editing the DVMT Pre-allocation using the EFI Shell

Warning for 4k / UHD screen owners:
Do not use the EFI shell to to edit the DVMT Pre-allocation for getting your screen to work. This bricked a user's machine already. Instead, make use of a patch explained in a lower section of this guide

http://www.tonymacx86.com/threads/guide-dell-xps-15-9550-skylake-gtx960m-ssd-via-clover-uefi.192598/

Yes. Messing around with settings not provided by the BIOS carries a certain amount of risk...

I have no idea on the applicability of the advice in that thread for your hardware, since your profile is not filled out with details...

Please provide complete details in your profile/signature
(Profile/Settings link in upper right corner of this site)

Mobo: manufacturer/model + bootloader(Clover/Chameleon/Chimera)
CPU: detailed CPU model + motherboard chipset
Graphics: all graphics devices + laptop internal screen resolution

For example, typical Ivy laptop:
Mobo: HP ProBook 4540s (Clover)
CPU: i5-3320m/HM76
Graphics: HD4000, 1366x768

Use CPU-Z on Windows to find CPU (Core iX-xxx) and motherboard chipset (HMxx), and graphics capabilities. For a laptop, these details are important and affect critical installation procedures.

Note: When specifying your bootloader, if using Clover legacy, please be sure to specify "Clover legacy"). Specifying "Clover" will be assumed as "Clover UEFI"

 

[sebasriostod]

Yes. Messing around with settings not provided by the BIOS carries a certain amount of risk...

I have no idea on the applicability of the advice in that thread for your hardware, since your profile is not filled out with details...

Please provide complete details in your profile/signature
(Profile/Settings link in upper right corner of this site)

Mobo: manufacturer/model + bootloader(Clover/Chameleon/Chimera)
CPU: detailed CPU model + motherboard chipset
Graphics: all graphics devices + laptop internal screen resolution

For example, typical Ivy laptop:
Mobo: HP ProBook 4540s (Clover)
CPU: i5-3320m/HM76
Graphics: HD4000, 1366x768

Use CPU-Z on Windows to find CPU (Core iX-xxx) and motherboard chipset (HMxx), and graphics capabilities. For a laptop, these details are important and affect critical installation procedures.

Note: When specifying your bootloader, if using Clover legacy, please be sure to specify "Clover legacy"). Specifying "Clover" will be assumed as "Clover UEFI"

Profile completed! please help

 

[RehabMan]

Profile completed! please help

http://www.tonymacx86.com/threads/g...e-i7-6700hq-intel-hd-530-using-clover.191921/

 

[sebasriostod]

http://www.tonymacx86.com/threads/g...e-i7-6700hq-intel-hd-530-using-clover.191921/

I appreciate your help but the guide's variation is not UHD

 

[RehabMan]

I appreciate your help but the guide's variation is not UHD

So, you'll have to adjust for that... See FAQ.