Radeon HD 7770

The Tahiti GPU has 4.31 billion transistors on a 365 mm² silicon wafer. Cape Verde has 1.5 billion transistors on a 123mm2 wafer. In its most complete configuration, implemented in the Radeon HD 7770 model, this GPU includes 10 Compute Units (CUs), each of which consists of four Vector Units (VUs). In turn, each vector block consists of 16 stream processors, which gives a total of 640 stream processors (shaders) based on the Graphics Core Next architecture.

Cape Verde has four raster operations units (ROPs) - exactly half of what is available in Tahiti, this provides 16 raster operations per cycle. Two 64-bit memory controllers are connected to rasterizers via a common interface. Thus, we get a 128-bit memory bus.

 Radeon HD 7770 Specifications 

Officially, the top card on the Cape Verde GPU is called the Radeon HD 7770 GHz Edition, which indicates a GPU frequency of one gigahertz. This is an important point, according to AMD, as each vendor will list "1 GHz" on their card's packaging, whether they use a reference board design or a "performance" model that has an original cooling system. Of course, we all know that the core frequency is only one of the components that affect the performance of a video card.

The Radeon HD 7770 1 GHz uses all 640 stream processors available for the Cape Verde core, which theoretically delivers 1.28 teraflops of compute performance. Each CU has four texture processing units, and their total number in the Radeon HD 7770 1 GHz reaches 40. Four ROPs are connected via a common interface to two 64-bit memory controllers. Thus, we have a 128-bit memory bus combined with 1 GB of GDDR5 graphics memory running at 1125 MHz.