Hello hello.
First thanks for giving attention to this thread!
I want to create the fastest possible system with the hardware I have.
What do I have and what is the plan?
ASUS Hyper M.2 x16 PCIe card with
2 x SSD 970 PRO NVMe M.2 512gb
I’m unable to create hardware(or fake) raid with nvme ssds
So the only option is software raid 0.
For now, the closest tutorial I found is this one
[https://www.reddit.com/r/archlinux/comments/n7hfwn/how_to_uefi_boot_software_raid0/]
I suspect I will need a little help with “translating” the command from arch to manjaro.
When I had time a month ago successfully installed manjaro with normal gui way on one nvme. But after the kernel update - it broke and cannot boot.
I have no idea if it was a specific version of the kernel or with all the kernels it breaks the boot of nvme pcie. I Don’t have the will to figure it out.
Is this some common problem on PCIe nvme?
I also have 64gb ram.
If successfully running a system on software raid for future improvement i want to try rapiddisk for extra speed. Never used before. But in theory, will extend the life of the SSD and will add extra speed.
What is your opinion?
I have one mechanical hard drive (1tb) for regular backup of the system. (Also in near future will have a trueNAS system)
My personal goal here is to create a script for nvme raid 0. So in case of an accident to put a USB and executable that script for a fresh installation.
With my poor knowledge, this will be a long journey.
And will start tomorrow 
If anyone has this already done - please share.