Late 2008 Aluminum 13" Macbook 8gb ram 250 SSD Ran El Capitan on it, and its currently running High Sierra, unsupported. Even with El Capitan, it would become extremely sluggish after a few minutes of use, revert back to normal for a bit, then back to sluggish use. It really becomes unbearable at times. I really do not know what to do, and I thought maybe someone would have any suggestions. Ive opened it, cleaned the dust out of it, but have no clue what else I can do.