ASUS HD 7970 DirectCU II TOP
The ASUS HD 7970 DCU II TOP card is a behemoth, taking up 3 slots on your motherboard and computer chassis. After getting over its size, you’ll start noticing the reason for it. Firstly there’s the incredibly huge heatsink that itself measures 50mmx270mmx125mm. The entire length of the card is 11-inches, the same as a reference HD 7970.
Of course, the 12-phase power Digi+ VRM requires a small change in the power requirements, in that the ASUS HD 7970 DCU II requires two 8-pin connectors rather than the 8-pin plus 6-pin connector on the standard HD 7970. Consequently the ASUS now requires a 600W PSU, while the standard HD 7970 only requires a 500W PSU.
So to keep the GPU cool, we have a massive aluminum heatsink with multiple fins spread out across the entire surface of the PCB, with six copper heatpipes ensuring adequate heat dissipation. The heatsink in turn is cooled by two 10mm fans that rarely touch 1,700 rpm, even when overclocked. Furthermore on the back of the card we have a 1mm perforated metal plate that covers the whole PCB area for additional cooling.
The bottom line of all this heatsink coverage is that we have an extremely quiet card, even when overclocked by 22%. Fan speeds while idling are 1,300 rpm, while under load they hover around 1,650 rpm. Temperatures remain impressive as well, with the maximum measured at 69°C (while overclocked) and idling at 35°C.
In addition to providing a cool and quiet atmosphere to work in, the ASUS HD 7970’s DirectCU II heatsink also has the benefit of easy overclocking. From the factory the card comes with respectably overclocked speeds of 1000MHz on the core clock and 5600MHz on the memory. That’s an 8% and 2% overclock on core and memory (respectively) compared to reference AMD speeds.
I personally managed to get 1125MHz on the core and 6300MHz on the memory at stock voltage. That’s a very impressive overclock of 12.5% on both core clock and memory speeds from factory defaults; an incredible 22% on core and 14.5% on memory speeds compared to reference AMD speeds.