That was the link I posted :)
Yeah, there's a reason it's free... I don't really want hardware RAID either. I was happy when it turned up in a secondhand server I wasn't expecting to have a RAID card, then less happy when I realised it wasn't useful.
What's the motherboard you have? Does moving the boot drive off SATA help - you can get NVMe to PCIe adapters for a few dollars if the board doesn't have an NVMe slot. The board may or may not be able to directly boot off them.
Second-hand fancier LGA1155 boards are probably not too hard to find either.
