The U.S. green card process seems to take an astonishingly long time (assuming you aren't taking advantage of corrupt government employees). A feeling of lock-in with your current job adds to the frustration, because quitting can jeopardize or reset a permanent residency application that has been going on for months.
U.S. immigrants, how long did your card take? Did it seem to benefit from theoretically-irrelevant factors like which company you worked for? And, does it seem like the high tech industry is any faster for acquiring a green card (compared to, say, these people who seem to get cards after crossing the border under questionable circumstances)?
An EB1 filing is the fastest - but you typically need a PhD or equivalent to qualify. Most other filings are in EB2/EB3 which approximate a MS/BS educational equivalent. EB1s could go as 'fast' as 1-2 years wheras EB2/EB3 could take 3-5 years.
These are typical numbers - counting from the day you file. I know folks that got it in just over a year in EB2 and folks that are still waiting 6 years after filing. All the best!