AMD Radeon HD 7870 GHz Edition Video Card Review

The AMD Radeon HD 7870 GHz Edition (Cont’d)

The Radeon HD 7870 GHz Edition uses a heatsink with aluminum fins, copper base, two 5 mm heatpipes and one 7 mm heatpipe, cooled by a 74 mm radial fan.

Figure 5: Heatsink

Figure 6: Heatsink

In Figure 7, you can see the video card with its cooler removed. It uses a voltage regulator with five phases for the GPU. The voltage regulator circuit uses a digital design and is controlled by a CHiL CHL8225G chip, with each phase driven by a Renesas R2J20658BNP (“DrMOS”) chip, which incorporates the three required transistors (“high side,” “low side,” and “driver”) and can switch at higher frequencies and provide higher efficiency. All coils use ferrite cores and all capacitors are solid.

Figure 7: AMD Radeon HD 7870 GHz Edition

Figure 8: Main voltage regulator

The reviewed video card uses eight Hynix H5GQ2H24MFR-T2C GDDR5 chips, each one storing 2 Gbit of data, making the 2 GB of memory available on this video card. Each chip is connected to the GPU through a 32-bit lane, creating the 256-bit datapath that is available. These chips can run up to 5 GHz. On this video card, they are accessed at 4.8 GHz, leaving a small 4% margin for you to i
ncrease the memory clock still within specifications. Of course, you can always try to push the memory clock above its specs.

Figure 9: Memory chips

Before seeing the performance results, let’s recap the main features of this video card.