Popping sound in SLI

[Tristor]

So, when I'm running Furmark I'm hearing a popping sound that sounds like arcing, however I haven't smelled anything off or noticed anything go wrong. It sounds like maybe something on the back of the bottom card is arcing to the metal cooler shroud on the top card. The cards are pretty close together since it's on a MicroATX board, but seem to be working fine and temps are not great, but manageable (around 80C on the top card, 67C on the bottom card at stock speed@100% fan).

Any thoughts? I'm a bit worried, since I don't like to hear what sounds like arcing going on in there. I'm not planning to leave the cards exactly like this, going to probably order a full-sized ATX board and what not to give them more space, but in the interim was planning to go for it.

 

[stahlhart]

This happens to me on occasion during stress testing also -- I'm guessing that it's probably expansion of metal and/or plastic components of the GPU due to heat.

 

[Sohaltang]

My whole rig snaps and pops when I push it. I posted about it an never got an answer. I too assume it's just metal expanding or contracting

 

[Tristor]

So, after further testing this ONLY happens in Furmark/OCCT. It didn't happen in any of the benchmarks (Firestrike, Vantage, etc.) and it doesn't happen in games. I'm assuming you guys are correct about metal expansion. It did certainly freak me out a bit. I set up my webcam to watch through the window and monitored on another screen while running Furmark and didn't see any sparks, so I'm guessing it's not actually arcing.