We run a SQL Server 2014 standard edition on a 94 GB RAM server with 82 GB RAM dedicated to SQL.

I know PLE is not the answer to all and we should not focus on it too much. But if you look at the image below, on one of our nodes, the PLE is very low, and stays low too. But we also have A LOT of free memory on that node. This seems to be the case for us on most days.

I feel like free memory is wasted memory, is that a correct assumption?

Why doesn't SQL Server not utilize this memory to store data pages in and drop them when it needs the memory for other applications?

Results

select * from sys.dm_os_process_memory

select * from sys.dm_os_memory_nodes

select @@version

Microsoft SQL Server 2014 (SP2-CU18) (KB4500180) - 12.0.5687.1 (X64) Jul 20 2019 21:27:07 Copyright (c) Microsoft Corporation Standard Edition (64-bit) on Windows NT 6.3 (Build 9600: ) (Hypervisor)

exec sp_readerrorlog