HP Omen 15-ek005na
The Omen 15-ek0005na is the Intel variant of the Omen 2020 series, mounting an Intel i7-10750H and an NVIDIA RTX 2070 Max-Q. It features an IPS 144hz Full HD panel, a RAID controller, 16GB of RAM (2x8GB @ 3200MHz, capped by the BIOS at a lower frequency) and 1TB of NVMe SSD by KIOXIA (KXG60ZNV1T02).
The 70Wh battery allows to use the laptop about 4 hours on battery. In particular, the CPU TDP is limited to 25W while on battery, compared to the 45W on AC. On Windows there is the possibility of increasing the TDP to 90W/107W (long/short), yet this is managed directly by the embedded controller (EC) and requires patching to allow this on Linux.
BIOS
The BIOS interface available is graphic but not many options are present. Secure Boot can be disabled as well as hyper-threading. The fan is set as "Always On" by default, which can be disabled from here. No "Advanced" tab is present, so that the RAM frequency cannot be increased (XMP is not enabled by default) and the CPU TPD cannot be tuned.
It is also possible to switch the graphics card used from "Hybrid" to "Dedicated".
Audio
The internal microphone works out of the box, but it is suggested to set up echo reduction since it is a dual-microphone array. See PulseAudio#Microphone echo/noise cancellation.
EC/Fan/CPU
The Embedded Controller is usually managed by the "OMEN Command Center", which is not available in Linux. Further debugging is needed and currently the only known addresses are 0x58, which corresponds to the ACPI temperature as found by sensors. By writing a temperature to this address (e.g. 90°C) it is possible to start the fan on demand (by letting the firmware believe through ACPI the CPU is hotter than it is).
Also, the EC manages the CPU TDP, so that it is not possible to exceed 90W by any mean (writing to the Intel RAPL driver is completely ineffective). On battery, it sets 25W maximum TDP, which is raised to 45W on AC. To reach 90W it is necessary to write onto the EC a binary file (extracted from Windows under the desired circumstances) as follows:
# cat EC6662.bin > /sys/kernel/debug/ec/ec0/io
The EC can be written and dumped by using iswAUR and setting ec_sys.write_support=1 as a kernel parameter. An EC dump for 90W can be downloaded from GitHub.