Just from reading experances on this and other forums there is no relation between the two, it can be anywhere between few days to few years.

USCIS is highly unpredictable and so any of the three options are equally likely.

thanks for voting guys, yes it's anyone's guess but I was hoping the votes will be based on my 2011 PD

you have to understand that PD is only relevant in the sense that you are allowed to file 485 etc if your PD is current. It has no impact on processing times.

@Z N Would PD be not used to deliver GC on FIFO basis?

@ramky boss, unfortunately no, as @Another Guy mentioned PD just deterimes if you can file your I485 and if it can be adjuricatd based on final action dates, actual time for I485 approval could be few weeks to few months and even years even if your PD is current.