I've tried to look for an answer for this high and low and can't find one. Hoping someone out there knows.

I have a PowerEdge R440 set up with 4 hard drives installed on a Perc H730. Drive 0 and 1 are on a RAID 1, and drive 2 and 3 are on a separate RAID 1. I notice that the activity lights for drive 0 and 1 blink together when there is activity. But for drive 2 and 3, only drive 3 activity light blinks. Drive 2 never blinks. I've checked the RAID settings in Lifecycle as well as in OpenManage and both say the RAID's are online and properly configured. There is a yellow non-critical note but from what I can tell it's because the hard drives might not have the right firmware for the PERC but that it shouldn't affect anything. 

Can anyone confirm if this is normal?