It won't affect your OC, depending on what all you do, i.e. if you multi-task a lot, or do a lot of imaging, video, CAD, VMs, etc theloss of DRAM can affect overall performance
Probably won't take a hit at all. 8GB is more than enough for just about anything including gaming, except maybe high end graphics or video manipulation.
It won't affect your OC, depending on what all you do, i.e. if you multi-task a lot, or do a lot of imaging, video, CAD, VMs, etc theloss of DRAM can affect overall performance