Capacity Management - Word Automation Services limits

Limit	Maximum value	Limit type	Notes
Input file Size	512 MB	Boundary	Maximum file size that can be processed by Word Automation Services.
Frequency with which to start conversions (minutes)	1 minute (recommended) 15 minutes (default) 59 minutes (boundary)	Threshold	This setting determines how often the Word Automation Services timer job executes. A lower number leads to the timer job running faster. Our testing shows that it is most useful to run this timer job once per minute.
Number of conversions to start per conversion process	For PDF/XPS output formats: 30 x MFor all other output formats: 72 x M Where M is the value of Frequency with which to start conversions (minutes)	Threshold	The number of conversions to start affects the throughput of Word Automation Services. If these values are set higher than the recommended levels then some conversion items may start to fail intermittently and user permissions may expire. User permissions expire 24 hours from the time that a conversion job is started.
Conversion job size	100,000 conversion items	Supported	A conversion job includes one or more conversion items, each of which represents a single conversion to be performed on a single input file in SharePoint. When a conversion job is started (using the ConversionJob.Start method), the conversion job and all conversion items are transmitted over to an application server which then stores the job in the Word Automation Services database. A large number of conversion items will increase both the execution time of the Start method and the number of bytes transmitted to the application server.
Total active conversion processes	N-1, where N is the number of cores on each application server	Threshold	An active conversion process can consume a single processing core. Therefore, customers should not run more conversion processes than they have processing cores in their application servers.  The conversion timer job and other SharePoint activities also require occasional use of a processing core. We recommend that you always leave 1 core free for use by the conversion timer job and SharePoint.
Word Automation Services database size	2 million conversion items	Supported	Word Automation Services maintains a persistent queue of conversion items in its database. Each conversion request generates one or more records. Word Automation Services does not delete records from the database automatically, so the database can grow indefinitely without maintenance. Administrators can manually remove conversion job history by using the Windows PowerShell cmdlet Remove-SPWordConversionServiceJobHistory.