generating calibre view costs too long time

hi everybody

I am using calibre to extract parameters of the layout, and I choose calibreview in the pex option. when i run pex, the "*.pex.netlist file" can be generated successfully(the "*.pex.netlist" file is about 200M), but after i set up the calibre view window, it costs too long time to generate calibre view successfully(generally 1day or more). how to generate the calibre view faster? 

thanks~