X1 Carbon Gen5 Running Sequoia With 4k
Running Sequoia on a Lenovo X1 Carbon Gen5
My daily workhorse is a trusty Lenovo X1 Carbon Gen5 picked up off Ebay earlier in the year for £130. With the i7, 16GB memory and 512GB NVMe it’s a pretty sweet deal and runs everything I need at speed. I figured I game rarely, and with my taste in games ending around Half-Life 2 era I’m unlikely to stress the HD 620 graphics much. If push really did come to shove I could get an external GPU and go from there.
Sequoia?
My old daily driver was a Mac Pro and my work machine is an M4 Pro. Sound bit of kit, but I’m not made of money! So fair to see I’m a Mac user. Initially the X1 was running Ubuntu and everything worked smoothly. Then I found tylernguyen’s repo which promised Sequoia running smoothly on the Gen6. Given the Gen5 is just a Kaby Lake equivalent I gave it shot … and it works great.
The problem
I then for my sins picked up a 4K monitor (an as-new Dell 32") from Facebook Marketplate for £50. Work machine and I’m getting 4K. Personal machine.. 1440P. Errrrr something is definitely not right here. After much faffing, playing with Stephane Madrau’s excellent SwitchResX I simply could not force 4K no matter what I did with my config.plist.
The solution
I was inspired by a Git issue comment where b0hrer mentioned he was using an identical machine to mine and had needed to flash the BIOS to enable him to set DVMT (GPU memory basically) to 64MB from the default 32MB. This, he promised, enabled 4K video.
I figured what the hell and ordered the kit required. A (Dollatek flashing USB doodah from Amazon)[https://www.amazon.co.uk/dp/B08HQB1VL8] and set to. Disassembled the laptop, peeled away the black plastic cover and exposed the BIOS chip and connected to it:
Following the instructions I found (here)[https://www.reddit.com/r/thinkpad/comments/16v26yl/guide_thinkpad_bios_reading_patching_and_flashing/] I paid very close attention to every step. Especially making sure I backed up my BIOS twice first and diff’d the files to ensure it was good. Granted I used an Ubuntu machine, but the instructions still pretty much held (using flashrom). At the end… I crossed my fingers, rebooted and saw to my amazement…
Booted up to Sequoia, changed my config.plist to match that of tylernguyen’s and I’ve got 4K video. Out of a machine never designed to do this, nor to run this operating system. Fantastic!
