Document Viewer High Memory Usage errors

I keep getting errors.   I have set the Maximum Memory Usage In Mbytes to 8000.  I also limited the file types to Powerpoint Presentations (.PPT,.PPTX) only for the time being.  The server does not show  any process consuming that much RAM.  I'm on

InternalException: Process of conversion file 786ecd90d48041fa888653dad3adbfe7.pptx to 786ecd90d48041fa888653dad3adbfe7.pdf has been terminated. Reasons for termination: High memory usage
at Telligent.Evolution.DocumentPreview.Implementation.FileConverterExecutor.ExecuteConversion(Type converterType, FileContainer sourceFile, String outputFileExtension, Boolean saveResult, ICentralizedFile originalFile)
at Telligent.Evolution.DocumentPreview.DocumentConversionJob.ProcessFile(ICentralizedFile file, String fileExtension, Int32 fileId)