Convert PDF To TIFF too slow, big trouble

I am a licensed customer, but I have problem converting PDF to TIFF.
We convert PDF to TIFF on AIX machine, and it’s super slow, and it takes about 15 seconds to convert one page PDF to TIF.
We have about 3000 daily businesses and each one contains 20 to 30 PDF, so performance is a really big issue for us.

@dennyTY

Can you please share the source code, the PDF file and system details like OS, so that we may investigate the same on our end.