I cannot say there is a relationship, but since I purchased my Nvidia 680 from MacVidCards I've started to get some very undesired behavior. At least 10 times my system will abruptly log out. One time I even got a kernel panic. I had never seen this abrupt log-out before and hadn't seen a kernel panic in forever. I have heard so many things good about MacVidCards and his operation. I just don't know what to make of my problems. When I run disk utility it seems to be mostly a relatively clean situation. TechTool has reported no issues and my system in other respects seems to run briskly.