Right now I'm using a SuperMicro AOC-SASLP-MV8. I have the card full of drives. I only use 7200 rpm 64mb cache drives. Would I benefit at all in upgrading my controller card to a better performing one?

 

 

If you mean update to a PCIe8x card; No - the 4x has more than enough bandwidth for 8 drives; particularly with how unraid uses them.

I believe PCIe4x (version 1 even) has 1,000MB/s capacity.  Most of your 7200rpm drives will be around 100 (maybe 150 at the edge of the drive, but average 100) MB/s.

so 8x100 = 800MB/s.  So even if you use 125MB/s you are just at the limit.  If your board is newer, I believe PCIe4x v2.0 is 2,000MB/s (which I think the card is v2.0 compatible). You have way more than enough bandwidth on that card.

you might save 30-90 min for a parity check.. it is probably not worth it.