OK, I spent most of the morning working on this 4870 trying to tame the heat problem. The GPU temps are great! Idle at around 42-43 C. It is the VDDC Slave temps that have me concerned. So I pulled the card this morning and installed additional heat sinks where I had not had them previously. It turned out to be kind of a hodge-podge of sinks using copper Enzotechs, aluminum Thermaltake, MC-21 Mosfet coolers and, oh yeah, another fan.
I spent quite a while on how to address the fact that not only does the vga cooler need air passing through the cooling fins and heat-pipes, but the other half of the card needs air too. So, I came up with what I thought would help get this done. Please don't laugh at my wiring, as I simply wanted to get the vid card hooked up, the fans running and see if any of this made any difference.
[IMG]<a href="http://s519.photobucket.com/albums/u351/Dashkatt/?action=view¤t=twinfanpreinstall.jpg" target="_blank"><img src="http://i519.photobucket.com/albums/u351/Dashkatt/twinfanpreinstall.jpg" border="0" alt="Twin Fan 4870"></a>[/IMG]
This is how it looked in the case:
[IMG]<a href="http://s519.photobucket.com/albums/u351/Dashkatt/?action=view¤t=4870-HR-03-GTTwin-Fan.jpg" target="_blank"><img src="http://i519.photobucket.com/albums/u351/Dashkatt/4870-HR-03-GTTwin-Fan.jpg" border="0" alt="Twin Fan Installed lighted"></a>[/IMG]
The idle temp is now from 39 to 41 C, about 3 or 4 degrees cooler I didn't expect a big reduction here since not much of what I added affected the gpu. The drop is probably due to a higher cfm fan.
The Slaves, #1, #2 & #3 were still quick to get hot under load but not as much. What was getting from 120 to 140 C was now running from 80 to 90 C. I did see a few temps above 100 C. I have not run Crysis yet but only did a video test on Furmark and ATI Tools.
I have both fans on a controller and will have to make some changes as I had to use a "Y" cable just to get them going. I've ordered another fan controller where I can hook up each fan separately. These are Thermaltake 120mm Smart Fans and they can easily run over 2500 RPMs. With the split cable they are probably only running around 1700 RPMS, so I hopefully can achieve additional drops in those Slave temps once I get them up to speed, (within decibel range that is).
I'm not sure what else I can do to keep those Slaves cool aside from some sort of liquid cooling and that is going to take a very custom-made sink to cover those specific areas of intense heat buildup.
Again, sorry for the crappy wiring job, typically my cases look a little more organized. If anyone has any additional suggestions, please post it here. I'm all ears...(or eyes).