The first of the 28nm generation.
The ASUS HD 7970 is completely based on the reference AMD design of the HD 7970. The PCB and heatsink are identical to our reference AMD HD 7970 card, measuring 11×5 inches. As you can see, both cards have a glossy finish, with a DVI, HDMI v1.4a, and a pair of DisplayPort v1.2 ports.
On the top we can see the two CrossFireX connectors, giving you the ability for a 4-way CFX setup, assuming you have a compatible motherboard with 4 or more PCIe slots. Speaking of which, the PCI-Express Gen 3.0 connector looks identical to existing PCIe 2.0 connectors; nothing new to see here.
Going back to the top, we have the dual-BIOS switch whereby AMD allows people to switch between the factory default settings in BIOS 2, and a custom setting in BIOS 1. The latter is the place where customers can flash their custom BIOS on the separate EEPROM chip with separate lanes; allowing for an impressively safe overclocking experience.
Going back we have the 8-pin and 6-pin power connectors, which are required from a minimum of 550W PSU. A CrossFire setup requires at least a 600W PSU. That’s incredibly low system requirement from the fastest single-GPU graphics card in the world, courtesy of the 28nm process.
The new Vapor Chamber that AMD has developed allows for better cooling with curved edges near the fan for better airflow. The fan itself has been redesigned with a bigger overall size and new blades, resulting in reduced fan noise and better airflow than previous generation cards.
And as we tested, the HD 7970 has an idle temperature (at stock speeds) of 34°C, going up to 75°C under load. Comparatively the stock AMD HD 6970 was measured at 35°C at idle and 77°C under load.
While the AMD Overdrive utility did give me the option to increase core clock and memory speeds, the ASUS GPU Tweak utility provided a tad bit more control with voltage tweaking as well. More importantly, though, GPU Tweak showed detailed graphs on GPU temperature, voltage and speeds. As such, it’s a worthwhile contender to the likes of MSI’s Afterburner utility.
Using either one of the software, the HD 7970 is locked at a maximum Core clock speed of 1125MHz and Memory speeds of 1575 MHz (effective 6300 MHz) over stock speeds of 925 MHz and 1375 MHz. You may think that at these speeds that card would be stable, but running Unigine Heaven benchmark for the second time resulted in a crash; every time. So ultimately I just settled in at speeds of 1125 MHz on the core and 1575 MHz on memory; a respectable 22% and 15% increase respectively over stock speeds.