The AMD Radeon HD 6790 (Cont’d)
In Figure 4, you can see the video card with its cooler removed and, in Figure 5, a close-up of the voltage regulator circuit.
The voltage regulator circuit of the reference model uses solid capacitors, ferrite-core coils (which make the regulator to have higher efficiency because they have lower energy loss than iron-core coils), and low RDS(on) MOSFET transistors (i.e., higher efficiency). This circuit uses a four-phase design to generate the GPU voltage.
The GPU heatsink can be seen in Figures 6 and 7. It has a copper base, three copper heatpipes (two five-mm and one eight-mm), aluminum fins, and a 75 mm radial fan.
The Radeon HD 6790 reference model uses eight 1 Gbit GDDR5 memory chips, making its 1 GB memory (1 Gbit x 8 = 1 GB). The chips used are H5GQ1H24AFR-T2C parts from Hynix, which support up to 1.25 GHz (5 GHz QDR). Since on this video card memory is accessed at 1 GHz (4 GHz QDR), there is still a huge 25% margin for you to increase the memory clock rate while keeping the chips inside the maximum they support. Of course you can always try to overclock the memory chips above their specs.
Before seeing the performance results, let’s recap the main features of this video card.