My 15" 2012 Retina Macbook Pro lags like crazy when switching desktops and opening applications. Screen also flickers. Had it repaired before but the issues came back. Geniuses said I was out of warranty so they just did a Software Repair. For proposed resolution, it says "Run ASD EFI and OS". Anyone know what that does and if it will help at all? I'm pretty sure its a hardware issue btw.