The Radeon HD 7000 series, codenamed "Southern Islands", is a family of GPUs developed by AMD, and manufactured on TSMC's 28 nm process. The primary competitor of Southern Islands, Nvidia's GeForce 600 Series (also manufactured at TSMC), also shipped during Q1 2012, largely due to the immaturity of the 28 nm process.
Architecture
Graphics Core Next was introduced with the Radeon HD 7000 Series. A GPU implementing Graphics Core Next is found on the Radeon HD 7730 and above branded discrete GPUs. A GPU implementing TeraScale (microarchitecture) version "Evergreen (VLIW5)" is found on Radeon HD 7670 and below branded discrete GPUs. A GPU implementing TeraScale (microarchitecture) version "Northern Islands (VLIW4)" is found on APUs whose GPUs are branded with the Radeon HD 7000 series. OpenGL 4.x compliance requires supporting FP64 shaders. These are implemented by emulation on some TeraScale (microarchitecture) GPUs. Vulkan 1.0 requires GCN-Architecture. Vulkan 1.1 requires actual 2nd Gen. of GCN or higher (here only HD 7790). On newer drivers Vulkan 1.1 on Windows and Linux is supported on all GCN-architecture based GPUs.
Multi-monitor support
The AMD Eyefinity-branded on-die display controllers were introduced in September 2009 in the Radeon HD 5000 Series and have been present in all products since.
Video acceleration
Both Unified Video Decoder (UVD) and Video Coding Engine (VCE) are present on the dies of all products and supported by AMD Catalyst and by the free and open-source graphics device driver#ATI/AMD.
OpenCL (API)
OpenCL accelerates many scientific Software Packages against CPU up to factor 10 or 100 and more. Open CL 1.0 to 1.2 are supported for all Chips with Terascale and GCN Architecture. OpenCL 2.0 is supported with GCN 2nd Gen. or 1.2 and higher. For OpenCL 2.1 and 2.2 only Driver Updates are necessary with OpenCL 2.0 conformant Cards.
Vulkan (API)
Vulkan 1.1 is supported for all with GCN Architecture with recent drivers on Linux and Windows. Vulkan 1.2 is available for GCN 2nd Gen or higher with Windows Adrenalin 20.1(and newer) and Linux Mesa 20.0(and newer).
Desktop products
The 28 nm product line is divided in three dies (Tahiti, Pitcairn, and Cape Verde), each one highly increasing shader units (32, 20 and 10 respectively). While this gives a high increase in single-precision floating point, there is however a significant departure in double-precision compute power. Tahiti has a maximum ¼ double precision throughput relative to its single precision throughput, while the other two smaller consumer dies can only achieve a 1/16 ratio. While each bigger die has two additional memory controllers widening its bus by 128 bits, Pitcairn however has the same front-end dual tesselator units as Tahiti giving it similar performance to its larger brethren in DX11 tessellation benchmarks.
Radeon HD 7900
Codenamed Tahiti, the Radeon HD 7900 series was announced on December 22, 2011. Products include the Radeon 7970 GHz Edition, Radeon HD 7970 and Radeon HD 7950. The Radeon HD 7970 features 2048 usable stream cores, whereas the Radeon HD 7950 has 1792 usable stream cores, as 256 out of the 2048 cores are disabled during product binning which detects defective areas of a chip. The cards are the first products to take advantage of AMD's new "Graphics Core Next" compute architecture. Both cards are equipped with 3 GB GDDR5 memory and manufactured on TSMC's 28 nm process. The Tahiti GPU is also used in the Radeon HD 7870 XT, released November 19, 2012. In this case one quarter of the stream processors are disabled, giving 1536 usable cores. Additionally, the memory interface is downgraded from 384-bit to 256-bit, along with a memory size reduction from 3 GB to 2 GB.
Radeon HD 7800
Codenamed Pitcairn, the Radeon HD 7800 series was formally unveiled on March 5, 2012, with retail availability from March 19, 2012. Products include the Radeon HD 7870 and Radeon HD 7850. The Radeon HD 7870 features 1280 usable stream cores, whereas the Radeon HD 7850 has 1024 usable stream cores. Both cards are equipped with 2GB GDDR5 memory (some 7850s offer 1GB) and manufactured on TSMC's 28 nm process.