"In Use" memory on a SQL Server box I have a SQL Server 2012 database server with 64GB of RAM. A process called DataPumpService runs on the same box and loads around 400 million records from 2700 flat files. 

I want to understand what process is consuming all the physical memory on the box, so I go to the Resource Manager (under Task Manager): 



As you can see from the screenshot, the In Use memory is around 61GB, but the Committed Bytes and Private Bytes for the two most memory-intensive processes are around 3.3GB. 

How can I find out what process contributes to such high In Use memory on this server?

Thanks.
It's SQL Server that's consuming all of this memory.  You aren't seeing the memory it's consuming because SQL Server is probably using "locked pages" which are not part of the server's working set, which is often all you'll see in Task Manager.

There's a detailed description on why this is on one of the MSDN Blogs.