Current goal is to support my 10 drive MDADM array, I'm 2 ports short with the 5805 controller so I'm trying to figure out most cost efficient way to add those ports but with some futureproofing in mind.
I think additional HBA might be best option in my case as it gives more flexibility and I'll probably upgrade drive size before I increase drive count again for space/power efficiency.
5805 is nasty, the card can not configure drives as JBOD...
get HBA card and you will be happy.
on my opnion
expander is still the good solution, since you can use dual links by assuming on HDD not SSD....
6 ports on expander, 2 ports connect to HBA, 4 ports available that supports 24 HDD's
I was thinking more HBA is better, but with limited PCi-e lane and simplicity to add more drives, expander is on my top list.
actually down sizing from 16 drives to 8 drives + hot spare ...
move old HDDs to another reborn server (backup server now) with total 12 HDD's.
I ditch out hardware RAID as now, just one exception: Hardware RAID on baremetal.