Originally Posted by PenguinPIE
Thanks for the tip. I have relocated the hard disks so there is nothing in the way of the bottom fan. It now idles at around 48c to 49c and my room is at 24c. Sounds like it should be idling cooler than that? I have been running all case fans at the lowest speed via fan control, not sure if that makes such big differences compare to your temps.
As you mention the bolded part above, I now see 2 areas of attention:-
1) Insufficient fresh ambient air
Thermaltake website does not list the CFM figure for this blue LED 120mm fan but I think it should be around 50 CFM at the max 1300rpm.
Frankly, even at this full speed, the 50CFM is not much, IMHO. And since you are using a fan controller to further take the speed down to the lowest possible rpm, I can imagine the GTX570 is starving for fresh air.
:- spin up this fan to its full 1300rpm. I think this is the least that you owe your GTX570.
(The Kandalf is designed to favour quietness over high airflow. So, watercooling or even fanless system is its main strength. This is why it has so few fans and at such low spinning speed.)
2) Hot air from 8400GS being recirculated
The single slot 8400GS' cooling design does not expel hot air out of the case and so I expect a good portion of the hot exhaust is being recirculated by the GTX570 above and by itself.
:- Your pic does not allow me to have good clean look at that area but I think the 8400GS is sitting on a (light blue) PCI slot?
If yes, then there is the 7th slot empty which can be used as an escape route for the card's hot exhaust.
-The basic and passive step is to remove that slot cover so that hot air might escape naturally.
-A stronger and active step is to add a PCI slot fan to extract hot air out. Note that this fan should be as short as possible so as to avoid air competition with the card's fan.
Thermaltake A2375 'long' PCI slot fan: (not preferred)
Thermaltake A2426 'short' PCI slot fan: (preferred)
I hope that with these 2 measures taken, your GTX570 will idle at around mid-40's (24C ambient).