Has any on the forum seen something similar? Any suggestions on what to look at next? If it is helpful to describe the server hardware, it's got 2 E5-2670 cpu and 256 GB of ram, and the database is hosted on 1.6TB raid 10 local storage (15K 300 GB drives). The workload is predominantly read and the queries are mostly fairly simple selects from a single large table generally specifying the primary key as part of the where clause along with a few other filters.
I have seen something similar. It was because of
large shared_buffers.