Dell ME4 Series Storage Read Latency

Hi Everyone, We manage a bunch of ME4 and ME5 Arrays. One of them has some read latency that we are looking into. I would appreciate anyone's experience.

It is a ME4 Running the latest firmware 280-14. All of the hard disks have had the firmware updated. 

(23 x 2.4TB 10k SAS SED) and 1 1.92 TB SED Read Cache Disk. 

When you look at the response times and queue depth there are 4 disks that have abnormally high queue depth and response times (see attached). 

Curious if anyone else has hit this and how it was resolved. 

I was thinking about replacing one of the disks that is experiencing high response times to see if it goes away. I just find it odd that 4 disks are doing this?