I run two 980s in SLI. Both fans work and are running at boot up but while under load and gaming only the top GPU has fans running. The bottom one just twitches a little bit every couple of seconds. Temps seem to differ around 20 degrees the hottest one being the top (64-70) and bottom is around (43-45). I tried switching the GPUs. Both ran at boot up but still only the top ones fans ran during gaming and bottom on twitched. How can I get both fans to run? I have had the pc for about 3 years not even sure if this was a thing from the start, never really paid the much attention to the fans till now.thanks.