PCI-Express x1 SATA 4 6Gb/s Ports Card Introduction
If this add is up it is still available.
I have two of these for sale as pictured. Both work perfectly. They were used on a MSI B550 and an Asrock B550 motherboard with no issues and were plug and play. I switched to a Netapp JBOD so no longer need these.
$20 each
Each has 4 ports to connect internal drives to.
Here is an example of one of the controllers:
https://www.amazon.ca/IOCrest-SI-PEX40064-Port-Controller-Components/dp/B00AZ9T3OU/ref=sr_1_3?crid=YFQY9KDL6XXZ&keywords=pcie%2Bsata%2B4%2Bx&qid=1692411765&s=electronics&sprefix=pcie%2Bsata%2B4%2Bx%2Celectronics%2C140&sr=1-3&th=1
