Lenovo ThinkPad P1

Getting Ubuntu to Install and Boot

Make sure you have enough space (defragment your drive - see HP ZBook Studio G4 for information on how to do that).

You can also shrink a Windows (NTFS) partition from inside the Ubuntu installer. I don't recommend it if you use BitLocker encryption though.

Burn the flash drive in GPT mode using Rufus. Use ISO mode (not DD mode).

Restart your computer.

You don't need to change the BIOS settings.

If you are using "UEFI BIOS version" 1.15, we HIGHLY recommend UPDATING TO A NEWER VERSION. You can do this using the Lenovo Vantage utility on Windows.

In the BIOS, make sure you are using DISPLAY > HYBRID GRAPHICS (I recommend this if you want to have battery life).

You can also allocate 512MB of video RAM instead of 256MB to make games faster.

Boot to the flash drive from the BIOS. You should see a GRUB screen. Before --- in quiet splash --- (you may have to press up and right arrow to get to it because it doesn't show line breaks. The "\" at the end of a line means the line continues onto the next "line" of the screen), insert modprobe.nouveau=0 so the installer doesn't freeze.

If something weird happens, it may be the case that your flash drive is corrupted, so burn the image to your flash drive again in Rufus and try again.

If Ubuntu prompts to check your filesystem when booting, don't let it check your filesystem. Just in case. It won't do much if it checks the filesystem but it may corrupt Windows partitions by mistake.

Now go into the installer. You can set the bootloader partition to the Windows bootloader partition. Now, where you shrunk your disk and now have free space on it, click on that partition, and click Change... > Mountpoint > / and click OK.

You can click OK on the next screen when it asks you to confirm.

Sources

Incredibly useful link: https://wiki.archlinux.org/index.php/Lenovo_ThinkPad_P1

Specs

Processor	Intel Core i7 8850H (not overclockable)
RAM	16 GB @ 2400MHz DDR4 (1x16GB SODIMM stick)
Solid State Drive	M.2-2280 SATA3 512 GB (approx. 476.837 GiB) Solid State Drive (theoretical max 600MB/s), expandable with 1 M.2-2280 NVMe slot
Optical Drive	None
Display	15.6" FHD 1920x1080
Video Card	Nvidia Quadro P1000 w/ 4GB vRAM (supports Vulkan and OpenGL)
Network Cards	Intel Dual-Band AX200 802.11ac/ax wireless, Gigabit (1Gb/s) Ethernet and PxE (network) boot via 2 USB Type-C ports using a compatible USB-C to Ethernet adapter
Battery	4 cell Li-Cylinder, 80Wh
USB	(2) USB 3.0, (1) 3.1 Gen1, (2) Thunderbolt (USB 3.1 Gen2 form factor)
Pointing Devices	Trackpad (Synaptics?)
External Video Port	Dedicated HDMI port
Integrated Webcam	720p integrated webcam
Network Accessories	USB Type C to Ethernet adapter for PXE boot, probably provided with the laptop
Warranty	4 year with Accidental Damage Protection (ADP)
Other Ports and Sensors	Fingerprint reader, color sensor, microphone

Additional information (with a different CPU) @ NotebookCheck