Ursprünglicher Beitrag von: Dan ,
Most likely your HD SATA cable is breaking down so it's fighting though a CRC battle between the drive & CPU every time you open or save a file. Here is the IFIXIT guide: [guide|5120|MacBook Pro 13" Unibody Early 2011 Hard Drive Cable Replacement] and you want to use the newer version of the cable: [product|IF163-041-2|MacBook Pro 13" Unibody (Mid 2012) Hard Drive Cable - Apple P/N 923-0104]. You'll want to put some tape down on the upper case where the cable rests as the ruff surface of the aluminum often wears the cable. I would strongly recommend after you install the new cable to do a full backup and then wipe your drive and reinstall the OS and restore your backup to make sure you don't have any corrupted files.