What's the fastest .Net PDF library to dump a bunch of bitmaps to PDF?

I have 开发者_高级运维around 10 System.Drawing.Bitmap elements, which I want to dump to PDF. When combining them to a single bitmap, and then writing this to PNG, this takes me about 150 ms.

Now I want to create a PDF out of my bitmaps (4 pages), but with PDFSharp this takes >2.5 seconds. Is there any library that is (way) faster at doing this?

NB. I draw the images on the surface in PDFSharp like:

 XGraphics gfx = XGraphics.FromPdfPage(page1);
 gfx.DrawImage(XImage.FromGdiPlusImage(/*bitmap*/));

edit Don't care about paid/free

Try ITextSharp. Very easy to use and learn.

I haven't tried it (performance-wise or other..), but aspose has a pdf component which comes with a trial-version.