Just as a follow up...

Still running Cats 8.8 with it setup like this -



And a low speed yate sitting on it. VRM temps hit ~80 - 84c during Furmark. Down from the 109c with Cats 8.7.



I removed the fan sitting over the top of the card and just had the 2 x 120mm blowing over the fan as seen here. (in this pic the fan is still on the HD4870, but I'm trying to show the location of the other 120mm that blow air across my PC).

So without the fan on the card, but the two other ones not so far away Furmark went to 117+C. This proves that airflow in a case is not enough to cool the VRMs. You will need specific airflow OVER the VRMs. Now keep in mind my card is running 850 Mhz core. If you are overclocked you need more airflow than just the case flow.