We're running SQL Server 2012 on Windows Server 2008 R2 for a our CRM and ERP services.
Unfortunately, the majority of the setup was outsourced to an "expert" company who neglected to provide any documentation. For this and various other reasons, this company was dropped and replaced. Bridges were burnt, so there's no real chance of getting any more information from them.
We're experiencing some quite laggy behaviour with the server. It isn't heavily loaded in terms of CPU and memory, and only deals with the odd request from the CRM and ERP clients.
The laggy behaviour seems to stem from the fact that SSIS is reading megabytes of data each second from the hard drive.
https://en.wikipedia.org/wiki/SQL_Server_Integration_Services
http://www.ssistalk.com/2009/11/04/ssis-what-does-the-ssis-service-actually-do-anyway/
From what I can find - SSIS is there to help import packages that were developed to run in the SQL Server. I've found a few articles about excessive write operations due to SSIS, but nothing about excessive reads.
I'm also trying to figure out if it is safe to remove SSIS.