This static parameter gives the maximum number of threads in the current .NET application domain that can convert HTML to PDF simultaneously.
This parameter must be set before the first conversion performed in the current application domain.
When this property is set with a negative value or zero the concurrency level is maximum. The default value is 4.

C# | Visual Basic | Visual C++ |
public static int PdfConverterConcurrencyLevel { get; set; }
Public Shared Property PdfConverterConcurrencyLevel As Integer Get Set
public: static property int PdfConverterConcurrencyLevel { int get (); void set (int value); }

Assembly: ExpertPdf.HtmlToPdf (Module: ExpertPdf.HtmlToPdf.dll) Version: 9.2.0.25824 (9.2.0.0)