Below are some more info
DB size is small around 14GB
Max SQL server memory set to 26000 MB and Total Physical memory of the server is 30 GB
Minimum memory per query set to 1024 KB
Database files spread across 3 disk, .mdf file in E:, .ndf file in g:\, .ldf file in F:\
F: and G:\ drives never face any space issue but E: sometimes faces space issue due to other DBs.
DB in full recovery model
Max row count of one of the table is 1crore. Other tables are of small size
But Same SQL instance host around 120 DBs which are giant (close to 1TB size) and has more traffic compared to my DB which is just 14GB.
Select query is mostly experiencing timeout.