A couple of days ago my early 2011 17-inch MacBook Pro started freezing up and wouldn't unfreeze until I held the power button. About a year ago I upgraded the ram to a pair of 4GB Corsair CMSX8GX3M2A1600C9 sticks. These have worked perfectly (so far).
Then while booting up after the freezes, it was sometimes stuck on a white screen without the Apple Logo, or when it did boot up had graphical artefacts just above the Apple logo. This made me think of the now-famous 2011 MacBook GPU issue, but just to be sure I put memtest on a USB key and ran it for a few hours, it didn't come up with any errors. Then I switched back the original RAM that came with the machine and it's working fine so far.
So now I'm left with the question if it is a broken GPU (because of the artefacts) or did my (seemingly) errorless RAM suddenly become incompatible with my laptop? (Which would seem odd after a year of working without a hitch)
Then while booting up after the freezes, it was sometimes stuck on a white screen without the Apple Logo, or when it did boot up had graphical artefacts just above the Apple logo. This made me think of the now-famous 2011 MacBook GPU issue, but just to be sure I put memtest on a USB key and ran it for a few hours, it didn't come up with any errors. Then I switched back the original RAM that came with the machine and it's working fine so far.
So now I'm left with the question if it is a broken GPU (because of the artefacts) or did my (seemingly) errorless RAM suddenly become incompatible with my laptop? (Which would seem odd after a year of working without a hitch)