What's the fastest way to convert Html to Pdf?

I have some "big" html files 4Mb +.

Then I convert one file to PDF via Pechkin ( .NET Wrapper for WkHtmlToPdf static DLL ). I can sleep peacefully for about 3-5 minutes.

The output PDF is 2Mb + and has about 500 pages inside.

var html = "...html...";
var data = HtmlToPdf2(res);
Console.WriteLine("HtmlToPdf2 done: " + sw.Elapsed);

      

        
        
        
      

    

...

private static byte[] HtmlToPdf2(string html)
{
    var pechkin = new SimplePechkin(new GlobalConfig());
    var pdf = pechkin.Convert(new ObjectConfig()
                            .SetLoadImages(true)
                            .SetZoomFactor(1.5)
                            .SetPrintBackground(true)
                            .SetScreenMediaType(true)
                            .SetCreateExternalLinks(true)
                            ,html);
}

      

        
        
        
      

    

My stopwatch says:

Start: 00:00:00.0007693
TransformXMLToHTML done: 00:00:03.6661490
HtmlToPdf2 done: 00:03:50.7784590
WriteAllBytes done: 00:03:50.7871326

      

        
        
        
      

    

My users will cry when they wait that long.