Huh? OCEAN is just a scripting language (a set of SKILL functions actually) to produce the netlist and post-process the results; in essence it performs the same task as ADE and is equivalent to ADE. It wouldn't affect the simulation time unless you'd picked simulation options that don't make sense.
It's quite likely that your models are suboptimal; you might want to try using the AHDL linter option, or the +diagnose switch on spectre which can help diagnose performance problems in transient simulations.
You might want to contact Cadence customer support at
http://support.cadence.com so that you can share more information and get more guidance as to how to address the problem you're seeing.
Regards,
Andrew