I'm aware of the power requirements, and thankfully I've co-located my "Home" lab in my companies generous offer of utilizing their rack at a co-lo. So power isn't an issue. (I also utilize NSX for connectivity and networking so only consume a single public IP... it's an awesome little side deal I worked out)I think the backplane is 6G max, so any raid card beyond that value will be useless. Maybe some other member will say the opposite.
However a 4 note VSAN would consume too much power as those machine are power hungry.
I also realize the backplane may or may not limit the speeds to 6gbs... but I'm still trying to get a Raid HBA that is on the current VSAN HCL as supported and still allows for the c6220ii to boot. My SAS ssd's are only 6gbs anyways (and on the HCL)... so yes while the 12GB sas card I had was overkill it still should have worked other than whatever the BIOS is doing to lock it out, and it's what I had in my older C6100 that worked just fine... sigh.
So anyway I'm basically curious what if any cards people may or may not have tried that allow bios to fully post and I'll try and cross reference with current VSAN HCL.