I recently added a second 6870 to my system (For CrossFire) and have noticed a massive increase in heat and noise while gaming. The top GPU seems to hit a high of 70C while the fan is at 70%, which is pretty loud and annoying.
My GPUs are up-side-down, which is just how my computer is. The bottom GPU is directly above my OCZ ZT 750W PSU, which blows out cool air directly into the bottom GPU. This keeps the GPU cooler, but the hot air seems to raise directly into the top 6870.
At the top-left of my rig is a Hyper212+ CPU Cooler, cooling an i7-2600k which is over clocked to 4.5ghz. I swamped the back fan (the fan on the back of the computer) to have it to blow IN instead of OUT. Now, it blows cool air directly into the Hyper212+ coolers fan (and a bit above it). This lowered my temps by 10C.
Anyways, I was wondering how I could keep my 6870's cooler and more quiet. There is an empty spot for a fan on my Antec 300 Illusion case, and was thinking of adding a fan there. Should I have that fan blow out, or blow in (Into the case). A fan there would blow DIRECTLY between the GPUs, which should help the top GPU stay cooler.
Any tips, comments, suggestions, etc are welcome! Have a nice day!
In trying different fan setups, I've found a side fan that blows in does help. As I understand it, GPUs vent hot air out the rear of the case, so you need to supply cold air to the GPUs, hence the fan should be blowing into the case. One thing I don't see is any mention of fans sucking air out of the case. That could result in a slow buildup of heat since the hot air doesn't escape so easily.
(Back)TOP-Fan Blows Out Hot Air ..This is the fan at the highest location. Its needed to fource hot air out.
Front-Fan (2) Blows IN. It helps to use both
Side-Fan Blows IN. This will help blow cool air to the GPU