Chosen Solution
Whenever the screen saver comes it is sooo slow. Like 1 frame per 10 secs. But then i unlock the laptop (at the 1 frame per 10 secs) it behaves normal. the laptop has 8gb ram and a samsung ssd so there is no reason for this to happen. Thanks!
Check your energy settings. Update (12/27/2017) I would start by replacing the HD SATA cable. This cable tends to wear and can cause excessive CRC errors when reading and writing to disk. Here’s the IFIXIT guide you’ll need to follow: MacBook Pro 13" Unibody Early 2011 Hard Drive Cable Replacement and here’s the part you’ll want: MacBook Pro 13" Unibody (Mid 2012) Hard Drive Cable. This is the newer version which is better constructed. I would also place some electricians tape on the upper case where the cable rests as the aluminum can abrade it. If that doesn’t fix things I think you’ll need to run Activity Monitor to see whats chewing your CPU’s cycles.