Yes that is long time really, and it is so unjust that people applied after you receive test invitation as invitation is part of the processing steps and it has nothing to do with each individual case.... but you can see some other applicants have been over 130 days since IP status received and they did not receive test invitation yet !!! it is obviously related to the mod of the immigration officer to invite someone after couple days ...or 200 days, since total processing time is 12 months no one can blame them.81 days from IP no test invite still.