I'm supporting a system running against a SQL Server 2008 R2. The server is a single-CPU box with 8 GB of memory. As traffic has increased, the server has started saturating, peaking to 100% CPU ever more often.
Disk I/O remains moderate (somewhat surprisingly).
Obviously, a new server would be the best option. But failing that, can I expect a noticable improvement from installing more RAM? Or does RAM only help for I/O issues (through caching)?