I wanted to reply to everyone with some success
using 918+ on latest release, 7.1 HP 800 G1 HASWELL, i got a 10 port and multiple 4 port pcie to sata extension cards working in redpill 7.1 Tested many different ways, just plug and play, this makes me very happy. Benchmark speeds were amazing too
Like Flyride said they are labeled as "port multipliers" on amazon but they all work full speed no problems on 7.1 redpill in pcie x16 port and pcie x1 ports
SO, now I've got a 918+ with like 18 available pcie 3.0 sata ports. Of course i am not sticking with this old motherboard, so maybe i'll update when rig is complete one day soon
I'll be listing them below.
WORKING PCIE 3.0 to SATA Expansion CARDS COMPATIBLE WITH REDPILL and 7.1. So Far......
4 Port Pcie to Sata Extension Card $29.99
IO CREST 4 Port SATA III PCI-e 3.0 x1 Expansion Card Non-Raid with Low Profile Bracket ASMedia 1064 SI-PEX40156
https://www.amazon.com/gp/product/B07VH57N3Q
4 port Pcie to Sata extension Card This one is only pcie 2.0!!!! i dont suggest! but works like if you use spin drives $23.99
SATA 3.0 4 Port PCIe Controller Card,PCI Express to SATA 3.0 6Gbps with 2U 4U Fixed Brackets,Plug and Play PCI E Cards,SATA 3.0 Expansion Card
https://www.amazon.com/gp/product/B07VH57N3Q
And my personal favorite, the TEN PORT CARD! YES!
10 port Pcie 3.0 to Sata Extension Card $55 on sale for amazon prime sale until midnight tonight
PCIE 4X SATA Card 10 Ports,with 10 SATA Cables and Low Profile Bracket,PCIE to SATA 3.0 6 Gbps Controller,PCIE to SATA Expansion Card,SATA Controller,SATA PCIE Card,ASM1166+JMB575 Chips
https://www.amazon.com/gp/product/B09FPHWP38 $55 on sale for amazon prime sale until midnight tonight
Hope this helps someone. I buy a lot of stuff so ask if you need something similar tested or tested in a different board chipset