Leaderboard

Enabling 4K External Display I had been seeing some queries about enabling 4K display for E7440 lately so I decided to spend some time on the matter. Unfortunately I don't own or have access to a 4K display but I do have a 2K display to test with. As expected the default settings can only display as high as 1080p. I did some experiments following existing guides found here in the forum and was successful getting 2K to display, I believe it should work for 4K as well. So here are the steps required: 1) Raise the DVMT pre-alloc from 32mb(default on this model) to 128MB in the BIOS. Since you can't access this setting from Dell's BIOS, you'll need to use the EFI shell to accomplish this. See my guide here. Below are the locations found for DVMT Pre-allocated and CFG Lock Set DVMT @ 0x255 to 0x4 Set CFG Lock @ 0xC8B to 0x0 (not sure if this necessary, but it didn't break anything) Here are the commands from EFI Shell: setup_var 0x255 0x4 setup_var 0xC8B 0x0 2) Update Config.plist file from bootpack above under Devices/Properties/PciRoot(0x0)/Pci(0x2,0x0) the following: framebuffer-cursormem = 00000003 framebuffer-fbmem = 00000003 framebuffer-stolenmem = 00000008 uncomment #framebuffer-unifiedmem by removing the # in front (Optional) That's it. FYI, the DVMT & CFGLock value will restore to default if you ever select Load Default in the BIOS. You'll need to redo the steps in #1 Updating BIOS does not remove the settings. Resources: https://osxlatitude.com/forums/topic/8723-enabling-dvidphdmi-and-increasing-vram-with-intel-haswell4th-gen-hd420044004600etc-igpu/