Computer does not boot with P4000 and NVIDIA drivers

I have a new Dell PC with an NVIDIA Quadro P4000 graphics card. I installed Ubuntu 18.10 on it. After the default installation, it works fine.

However, I need the NVIDIA drivers. I have installed versions 390 (from the Ubuntu software updates tool), and versions 410 and 418 from NVIDIA's PPA site. All present the following problem: booting fails, immediately after Grub's menu, with a purple screen. The machine is not responsive, and I cannot get to a terminal.

Following the advice here, I added nomodeset to Grub's kernel parameters. When I do that, the machine boots, I can run benchmarks, nvidia-settings runs, and things seem to be fine.

However, I suspect that's just a stopgap hiding a deeper problem. I have read many answers and followed their advice (for example this) without any success.

The computer also has an integrated Intel display, and my suspicion at the moment is that there's a conflict between Intel and NVIDIA when modeset is enabled. However, I don't know how to start testing that hypothesis.

Any advice would be appreciated. Here's a little bit more data about the machine; I can provide more details if needed. The BIOS is dated 11/01/2018. Secure boot has been disabled the whole time.

$ sudo lshw -short # I have removed many irrelevant lines
H/W path Device Class Description
====================================================== system OptiPlex 7060 (085A)
/0/0 memory 64KiB BIOS
/0/9 memory 32GiB System Memory
/0/14 memory 384KiB L1 cache
/0/15 memory 1536KiB L2 cache
/0/16 memory 12MiB L3 cache
/0/17 processor Intel(R) Core(TM) i7-8700 CPU @ 3.20GHz
/0/100 bridge 8th Gen Core Processor Host Bridge/DRAM Registers
/0/100/1 bridge Xeon E3-1200 v5/E3-1500 v5/6th Gen Core Processor PCIe Con
/0/100/1/0 display GP104GL [Quadro P4000]
/0/100/1/0.1 multimedia GP104 High Definition Audio Controller
/0/100/2 display Intel Corporation
/0/100/8 generic Xeon E3-1200 v5/v6 / E3-1500 v5 / 6th/7th Gen Core Process
$ cat /proc/version
Linux version 4.18.0-16-generic (buildd@lcy01-amd64-022) (gcc version 8.2.0 (Ubuntu 8.2.0-7ubuntu1)) #17-Ubuntu SMP Fri Feb 8 00:00:57 UTC 2019

1 Answer

The best solution I've been able to find is to add

i915.modeset=0

to Grub's kernel parameters. This allows the Nvidia card to use modesetting. Also, this seems to confirm my suspicion that the problem was the interaction between two active video cards: the built-in Intel and Nvidia's.