The cooler and shroud
When we remove the cooler and shroud, the sheer size is clearly recognisable. The shroud is a combination of plastic and aluminium on the outer case and metal on the underside to cool the memory chips. The thermal pads are indicative of the 8 memory modules on the PCB itself. The fan is attached to the metal bracing, which pushes air through the heatsink and towards the rear. The heatsink no longer uses a heat pipe design but instead employs a vapour chamber to ensure better cooling and consequently quieter operation. Its construction is a combination of aluminium fins and copper base.
The bare PCB
The bare PCB reveals the layout of the individual components. Unlike the HD6870, the power circuitry has gone back to its traditional placement towards the power connectors. The GPU area is set in the middle and surrounded by 8 memory modules.
HD6970 vs. HD6950 PCB
The PCBs used for both the HD6950 and HD6970 are identical, the only differences being the components used on-board. The near HD6970 sports an 8 pin PCIe power connector instead of a second 6 pin connector. The memory modules and GPU also cater to the higher end nature of the HD6970. Apart from those, it would be hard to distinguish the two boards at a mere glance.
The Cayman GPU
The Cayman core seen here has a die size of 389 mm squared, significantly larger than the 255mm squared Barts core and the 334mm squared Cypress core. This is the largest AMD core since the notorious R600 core design which came at 420 mm squared. The fabrication is still on the 40nm process due to the lack of readily available 32nm or 28nm manufacturing.
The 8 Hynix memory modules
The memory modules are once again GDDR5 chips sourced from Hynix rather than Samsung. The H5GQ 2H24MFR ROC 045A chips operate at 1.5V. The RO denotes that the memory is rated at 6GHz, superior to the modules used on the HD6950. Unlike the HD6870, the memory controller is more robust and can benefit from the full potential of the Hynix module. Each module is 256MB to give a total of 2GB of VRAM.
The VRM circuitry
The CLA1108-4 chokes are unique additions to the card for a robust VRM power circuitry. The card appears to use a 6 phase PWM design, similar to the HD6950.
The Volterra VT1556MF voltage controller
The Volterra VT1556MF voltage controller sees its first use on the HD6900 series. Currently, only ASUS’s SmartDoctor is known to support voltage tweaking.
