About my Mac: Macbook Pro 2011 16GB RAM (Other World Computing) 480GB SSD (Other World Computing) Yosemite Beta I had Yosemite on my computer for a couple of weeks now. A noticeable bug from the beginning has been graphic glitches when launching apps (a quick flicker of lines and distortion on the screen). But this didn't seem to have any major effect on the performance. Until I was editing some RAW images in iPhoto. While making some editing adjustments on a photo, the screen went haywire, and the lines and distortion remained on the screen. I couldn't navigate to the restart button, so I forced a shut down using the power key, and started back up. I noticed some horizontal reddish lines on the startup screen, but once the apple logo popped up, everything seemed fine. Then I was stupid enough to try editing photos again. The same thing happened, but now when I restart, the lines are still there through the Apple Logo. The status bar begins loading, then cuts to a gray screen with no lines, but nothing happens after that. The computer seems to be trying to do something, because the fan eventually kicks in, and the underside of the laptop gets pretty hot. When I launch holding down Command R, or Command Option R, the same thing happens once it tries to load. Holding down the option key, I am only given the option of the main hard drive, and occasionally an EFI boot drive (that went to a blue screen similar to the Windows Blue Screen of Death). I plugged in an external HD with Mavericks, and got the same gray screen. I'm able to access the HD from another computer via Target mode, and the drive seems fine, which leads me to believe this could be a hardware issue. Did my logic board/graphics just happen to crap out on me after installing Yosemite, or does the OS have something to do with the issue?