Very Slow rMBP Boot.

this is the 2.6, 512gb 8 gb version.

Boot goes to apple almost instantly, but then the rotating circle keeps going on for 2-5 mins. sometimes it doesnt even load.

these are the things i have tried:
pram / smc reset many times
selected the ssd as my start up drive.
taken everything off from login startup apps
reinstalled from scratch. Not from an image.
Did the apple hardware test- everything passed.
Nothing plugged in


I have no idea whats going on. I have tested the speed of the SSD once logged in and everything is ok. 450+ read/write speeds. Temps are fine. Fans are ok. No lagging once in.

It really is driving me insane. Do you guys have any other suggestions?

 

did that. Also verified and fixed disk permissions through disk utility.

Did verbose (command + v) and everything went fine, and goes all the way to "macbook pro (somthing) ok:"

then just stays there. i press keys and just writes what i press like in DOS. then it loads in the same about of time 2-5 minutes.

 

have not tried that. ( at work right now, no computer). What would i be able to gather from that? If it starts up fine, its an issue with an app or something? Just like to add that this is happening with a completely fresh isntall, nothing downloaded or installed.

 

so that didnt work, during verbose start up, it hangs on "macx_swapon success"

couple of things ive noticed as well:

dynamic gpu switching is not working sometimes.

when i restart, i get a very very quick flash of black with white letteringon the top left of the screen when everything else is gray.

this is very weird.

 

any other suggestions?

 

update:


Apprently the logic board has to be replaced. Kind of weird that it happened out of nowhere. At least i know theres nothing i couldve done, because it was driving me crazy that i couldnt figure it out.