seeing as most the tech support are clueless with performance analysis I will help the OP out.
Run this command
statistics show-periodic -object disk:raid_group -instance /node1_aggr1/plex0/rg0 -counter read_ops|write_ops -interval 1 -iterations 60
you will need to be in Priveleged Mode - Advanced.
From there you can work out your read/write % and actually work out how to fix it, DO NOT Involve netapp support - they will read off a script and ask for a perfstat then a week later they will say "buy more disk" rather than, oh you have high latency? maybe you need to re-balance the aggregate? or reallocate or add jumbo frames or anything constructive lol.