AMD APU

AMD Accelerated Processing Unit, formerly known as Fusion, is a series of 64-bit microprocessors from Advanced Micro Devices, combining a general-purpose AMD64 central processing unit and 3D integrated graphics processing unit on a single die.
AMD announced the first generation APUs, Llano for high-performance and Brazos for low-power devices, in January 2011 and launched the first units on June 14. The second generation Trinity for high-performance and Brazos-2 for low-power devices were announced in June 2012. The third generation Kaveri for high performance devices were launched in January 2014, while Kabini and Temash for low-power devices were announced in the summer of 2013. Since the launch of the Zen microarchitecture, Ryzen and Athlon APUs have released to the global market as Raven Ridge on the DDR4 platform, after Bristol Ridge a year prior.
AMD has also supplied semi-custom APUs for consoles starting with the release of Sony PlayStation 4 and Microsoft Xbox One eighth generation video game consoles.

History

The AMD Fusion project started in 2006 with the aim of developing a system on a chip that combined a CPU with a GPU on a single die. This effort was moved forward by AMD's acquisition of graphics chipset manufacturer ATI in 2006. The project reportedly required three internal iterations of the Fusion concept to create a product deemed worthy of release. Reasons contributing to the delay of the project include the technical difficulties of combining a CPU and GPU on the same die at a 45 nm process, and conflicting views on what the role of the CPU and GPU should be within the project.
The first generation desktop and laptop APU, codenamed Llano, was announced on 4 January 2011 at the 2011 Consumer Electronics Show in Las Vegas and released shortly thereafter. It featured K10 CPU cores and a Radeon HD 6000 series GPU on the same die on the FM1 socket. An APU for low-power devices was announced as the Brazos platform, based on the Bobcat microarchitecture and a Radeon HD 6000 series GPU on the same die.
At a conference in January 2012, corporate fellow Phil Rogers announced that AMD would re-brand the Fusion platform as the Heterogeneous System Architecture, stating that "it's only fitting that the name of this evolving architecture and platform be representative of the entire, technical community that is leading the way in this very important area of technology and programming development." However, it was later revealed that AMD had been the subject of a trademark infringement lawsuit by the Swiss company Arctic, who used the name "Fusion" for a line of power supply products.
The second generation desktop and laptop APU, codenamed Trinity, was announced at AMD's 2010 Financial Analyst Day and released in October 2012. It featured Piledriver CPU cores and Radeon HD 7000 series GPU cores on the FM2 socket. AMD released a new APU based on the Piledriver microarchitecture on 12 March 2013 for Laptops/Mobile and on 4 June 2013 for desktops under the codename Richland. The second generation APU for low-power devices, Brazos 2.0, used exactly the same APU chip, but ran at higher clock speed and rebranded the GPU as Radeon HD 7000 series and used a new I/O controller chip.
Semi-custom chips were introduced in the Microsoft Xbox One and Sony PlayStation 4 video game consoles, and subsequently in the Microsoft Xbox Series X and Series S|Xbox Series X|S and Sony PlayStation 5 consoles.
A third generation of the technology was released on 14 January 2014, featuring greater integration between CPU and GPU. The desktop and laptop variant is codenamed Kaveri, based on the Steamroller architecture, while the low-power variants, codenamed Kabini and Temash, are based on the Jaguar architecture.
Since the introduction of Zen-based processors, AMD renamed their APUs as the Ryzen with Radeon Graphics and Athlon with Radeon Graphics, with desktop units assigned with G suffix on their model numbers to distinguish them from regular processors or with basic graphics and also to differentiate away from their former Bulldozer era A-series APUs. The mobile counterparts were always paired with Radeon Graphics regardless of suffixes.

Features

Heterogeneous System Architecture

AMD is a founding member of the Heterogeneous System Architecture Foundation and is consequently actively working on developing HSA in cooperation with other members. The following hardware and software implementations are available in AMD's APU-branded products:

Type	HSA feature	First implemented	Notes
Optimized Platform	GPU Compute C++ Support	2012 Trinity APUs	Support OpenCL C++ directions and Microsoft's C++ AMP language extension. This eases programming of both CPU and GPU working together to process support parallel workloads.
Optimized Platform	HSA-aware MMU	2012 Trinity APUs	GPU can access the entire system memory through the translation services and page fault management of the HSA MMU.
Optimized Platform	Shared Power Management	2012 Trinity APUs	CPU and GPU now share the power budget. Priority goes to the processor most suited to the current tasks.
Architectural Integration	Heterogeneous Memory Management: the CPU's MMU and the GPU's IOMMU share the same address space.	2014 PlayStation 4, Kaveri APUs	CPU and GPU now access the memory with the same address space. Pointers can now be freely passed between CPU and GPU, hence enabling zero-copy.
Architectural Integration	Fully coherent memory between CPU and GPU	2014 PlayStation 4, Kaveri APUs	GPU can now access and cache data from coherent memory regions in the system memory, and also reference the data from CPU's cache. Cache coherency is maintained.
Architectural Integration	GPU uses pageable system memory via CPU pointers	2014 PlayStation 4, Kaveri APUs	GPU can take advantage of the shared virtual memory between CPU and GPU, and pageable system memory can now be referenced directly by the GPU, instead of being copied or pinned before accessing.
System Integration	GPU compute context switch	2015 Carrizo APU	Compute tasks on GPU can be context switched, allowing a multi-tasking environment and also faster interpretation between applications, compute and graphics.
System Integration	GPU graphics pre-emption	2015 Carrizo APU	Long-running graphics tasks can be pre-empted so processes have low latency access to the GPU.
System Integration	Quality of service	2015 Carrizo APU	In addition to context switch and pre-emption, hardware resources can be either equalized or prioritized among multiple users and applications.

Feature overview

APU or Radeon Graphics branded platforms

AMD APUs have CPU modules, cache, and a discrete-class graphics processor, all on the same die using the same bus. This architecture allows for the use of graphics accelerators, such as OpenCL, with the integrated graphics processor. The goal is to create a "fully integrated" APU, which, according to AMD, will eventually feature 'heterogeneous cores' capable of processing both CPU and GPU work automatically, depending on the workload requirement.

TeraScale-based GPU

K10 architecture (2011): Llano

"Stars" AMD K10-cores
Integrated Evergreen/VLIW5-based GPU
Northbridge
PCIe
DDR3 memory controller to arbitrate between coherent and non-coherent memory requests. The physical memory is partitioned between the GPU and the CPU.
Unified Video Decoder
AMD Eyefinity multi-monitor-support

The first generation APU, released in June 2011, was used in both desktops and laptops. It was based on the K10 architecture and built on a 32 nm process featuring two to four CPU cores on a thermal design power of 65-100 W, and integrated graphics based on the Radeon HD 6000 series with support for DirectX 11, OpenGL 4.2 and OpenCL 1.2. In performance comparisons against the similarly priced Intel Core i3-2105, the Llano APU was criticised for its poor CPU performance and praised for its better GPU performance. AMD was later criticised for abandoning Socket FM1 after one generation.

Bobcat architecture (2011): Ontario, Zacate, Desna, Hondo

Bobcat-based CPU
Evergreen/VLIW5-based GPU
Northbridge
PCIe support.
DDR3 SDRAM memory controller to arbitrate between coherent and non-coherent memory requests. The physical memory is partitioned between the GPU and the CPU.
Unified Video Decoder

The AMD Brazos platform was introduced on 4 January 2011, targeting the subnotebook, netbook and low power small form factor markets. It features the 9-watt AMD C-Series APU for netbooks and low power devices as well as the 18-watt AMD E-Series APU for mainstream and value notebooks, all-in-ones and small form factor desktops. Both APUs feature one or two Bobcat x86 cores and a Radeon Evergreen Series GPU with full DirectX11, DirectCompute and OpenCL support including UVD3 video acceleration for HD video including 1080p.
AMD expanded the Brazos platform on 5 June 2011 with the announcement of the 5.9-watt AMD Z-Series APU designed for the Tablet market. The Desna APU is based on the 9-watt Ontario APU. Energy savings were achieved by lowering the CPU, GPU and northbridge voltages, reducing the idle clocks of the CPU and GPU as well as introducing a hardware thermal control mode. A bidirectional turbo core mode was also introduced.
AMD announced the Brazos-T platform on 9 October 2012. It comprised the 4.5-watt AMD Z-Series APU and the A55T Fusion Controller Hub, designed for the tablet computer market. The Hondo APU is a redesign of the Desna APU. AMD lowered energy use by optimizing the APU and FCH for tablet computers.
The Deccan platform including Krishna and Wichita APUs were cancelled in 2011. AMD had originally planned to release them in the second half 2012.