If you are EB2 ROW (obviously), you can file 140 and 485 concurrently. With a premium processing for 140 (without an RFE) you should know your 140 status in almost 3 weeks time. If you file 485 concurrently, with Biometrics and all, a happy path scenario would make you green in not more than 4 to 6 months. Also depends on whether your processing center is Texas or Nebraska? Historically, Nebraska is faster. In 2014, my ex-roommate's EB2 ROW 485 got approved in about 90 days after PERM approval. Good luck my friend.

Reference:
http://www.uscis.gov/green-card/green-card-through-job/previous-pending-employment-based-i-485-inventory/pending-employment-based-i-485-inventory

http://www.trackitt.com/usa-discussion-forums/i485-eb/1463216525/eb2-row-nebraska-let-s-keep-track