The file upload provides the settings related to uploaded content used for PowerPivot imports and the Mash-Pit. The destination should be set in UNC format in multi-server deployments ("\\server\directory"), since the directory may need to be accessed from multiple machines. It is also recommended that this directory have sufficient capacity to handle numerous uploaded files.
Set the maximum file size that will be accepted from user uploads. Buffer size determines the amount of data that can be uploaded per "chunk". Increasing this value improves upload speeds, but may also choke web servers if too many concurrent uploads occur at the same time.