The high-end GPU war is both exciting and frustrating. In the last six months we have seen AMD take the lead with the Radeon HD 7970 and then watched NVIDIA stomp all over it with the GeForce GTX 680. But now we have the HD 7970 GHz Edition which represents the latest attempt by AMD to regain the performance lead. But has it worked?
The Tahiti XT2 GPU that sits at the heart of the Radeon HD 7970 GHz Edition is identical to the Tahiti XT GPU in every respect save for the clock speeds. It has the same number of transistors, the same number of Stream Processor and the same number of Texture Mapping Units. As mentioned the clock speeds are the only area where the Tahiti XT2 differs from its predecessor. The core clock speed of the GPU on the Radeon HD 7970 GHz Edition is 1,000MHz which is 75MHz higher than the HD 7970. The memory clock speed of the GHz Edition card is also higher sitting at 1,500MHz instead of the 1,375MHz of the GDDR5 found on the standard HD 7970. The new drivers include a feature called PowerTune with Boost which ramps up the GPU clock speed if thermal conditions permit however AMD has been a little too cautious with this feature and limited the boost to 50MHz which sees the HD 7970 GHz Edition card running at 1,050GHz most of the time.
In terms of performance the Radeon HD 7970 GHz Edition officially earns the title of “fastest single GPU graphics card” and if AMD uses two of these GPUs on the HD 7990 then it’s likely that the dual GPU crown will find itself a new home too. The GTX 680 is still a powerful card but its raw computing power only earns it top honours in synthetic benchmarks like Heaven 2.5 and 3DMark 11. While the HD 7970 GHz Edition is the fastest card overall the new drivers also make the normal HD 7970 perform almost on a par with the GTX 680 which makes owning one even more exciting.
Current HD 7970 owners are now faced with the problem of seeing if their cards can be turned into GHz Editions – with a bit of effort. As our review of the HD 7970 in PCFormat March 2012 proved, the standard card can be overclocked to speeds in excess of the GHz Edition’s core and memory clock speeds. So turning your vanilla card into a GHz Edition card is as simple as overclocking but those eager to flash the BIOS of the HD 7970 GHz Edition onto their vanilla HD 7970 should note that early attempts at this have not yielded any successes. The performance benefits of the new Catalyst 12.7 beta drivers cannot be understated and there is little doubt that AMD’s driver team plays a very crucial role in squeezing the best performance out of the silicon.
Local stock of the GHz Edition cards have yet to make to be available so pricing is still unconfirmed but an educated guess would put the pricing of the HD 7970 GHz Edition around the R5,500 to R6,000 mark. At this price point the AMD card will be the same price as the cheapest GTX 680. If you currently have an HD 7970 there is little reason to buy a GHz Edition card and even then the HD 7950 is still one of the best cards to buy in terms of price and performance.
Price R TBA
Interface PCI-E 3.0
Fabrication process 28nm
Transistor count 4.3 billion
Core clock 1000MHz
Stream Processors 2048
Texture Units 128
Memory 3GB GDDR5
Memory clock 1500MHz (6000MHz effective)
Memory Interface 384-bit
DirectX 10 performance
DirectX 11 performance
Futuremark 3Dmark 11