what is an accelerated processing unit

8/7/2019 What is an Accelerated Processing Unit

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What is an accelerated processing unit (APU)?

An APU integrates a CPU and a GPU on the same die thus improving

data transfer rates between these components while reducing power

consumption. APUs can also include video processing and other

application-specific accelerators. Examples: Intel¶s Sandy

Bridge, AMD Fusion and NVIDIA¶s Project ³Denver´

Make more sense now? An APU is the combination of a CPU

(generally a multi-core one), a graphics processing unit, and then

some way to get them to play together nicely.

Why do this in the first place? Because it turns out that GPUs are

good at things besides graphics, so the CPU can offload computing

tasks to them. To optimize this cooperation bottlenecks between theCPU and the GPU had to be removed, the result being the APU!

Accelerated Processing Units - What are they?

AMD's new Accelerated Processing Unit concept is a fusion of the

tradition x86 processor core (CPU) and graphics processing unit

(GPU). By bringing both the CPU and GPU together, many of the

latencies of CPU to GPU communication can be reduced - plus both processing arrays can access the same data without having to copy it

over slow or high latency system interconnects. AMD's purchase of

ATI Technologies in 2006 was with the FUSION APU concept in

mind.



APU's are also coming to the mainstream desktop space, with existing

x86 technology cores from the Athlon II processor line up being

combined with DirectX 11 GPU cores offering graphics capabilities

well in excess of the current mainboard integrated graphics cores -and Intel's Sandy Bridge, too.

This processing power is not being used only for enhanced med ia

consumption but also for application acceleration - AMD fusion

APU's currently accelerate more than 50 popular titles , with more on

the way. This is made possible by AMD's support for hardware

accelerated OpenCL using their GPU technology - an open standard

that any vendor can benefit from using.

Future developments of the AMD Fusion APU concepts will bring far

higher graphics and media performance to the basic desktop

platform, as less power will be needed to deliver higher performance

through the use of AMD Accelerate Application Processing. Software

companies can leverage the advantage of AMD APP by using

common and open standard technologies such as Microsoft's

DirectCompute 5 (part of DirectX 11) and OpenCL.

The Fusion APU concept is a fundamental shift in thinking about

what components are important for delivering the best user

experience with low power and low cost, as well as outright top

performance.

Athlough the future is fusion, AMD's new x86 architecture codenamed

Bulldozer (for high performance desktops and servers) launching this

year without integrated GPU's. This is widely predicted to be different

in 2012, where the new Bulldozer+ cores will be mated with SIMD

arrays to create high performance enthusiast parts for gamers and workstation users to use.



Nvidia Announces Plans to Build Own

Accelerated Processing Units for PCs, Ser vers.

Nvidia Corp., a leading designer of graphics processors and multimedia system-on-chips, on Wednesday announced plans to

develop its own ARM-based micro-architecture. The company intends

to integrate future custom central processing unit (CPU) cores into its

graphics processing units (GPUs) and install the latter into both

personal computers and servers.

Known under the internal code-name "Project Denver", this initiative

features an Nvidia CPU running the ARM instruction set, which will

be fully integrated on the same chip as the Nvidia GPU. This new

processor stems from a strategic partnership, also announced today,

in which Nvidia has obtained rights to develop its own high

performance CPU cores based on ARM's future processor

architecture. In addition, Nvidia licensed ARM's current Cortex-A15

processor for its future-generation Tegra mobile processors.

Nvidia's intention to integrate ARM-based microprocessor cores had

been known for over a year now. Back in November, 2010, the

company even unveiled plans to develop a so-called Echelon design

chip that incorporates a large number (~1024) of stream cores and a

smaller (~8) number of latency-optimized CPU-like cores on a single

chip. As a result, the current announcement is just a formal

confirmation of Nvidia's plans to enter the market of accelerated

processing units (APUs, the chips that feature both CPU and GPU

cores on the same die) eventually.

"ARM is the fastest-growing CPU architecture in history. This marks

the beginning of the Internet Everywhere era, where every device

provides instant access to the Internet, using advanced CPU cores

and rich operating systems. ARM's pervasiveness and open business

model make it the perfect architecture for this new era. With Project

Denver, we are designing a high-performing ARM CPU core in

combination with our massively parallel GPU cores to create a new



class of processor," said Jen-Hsun Huang, president and chief

executive officer of Nvidia.

While it remains to be seen how successful ARM architecture will be

in servers, it should be stressed that Nvidia makes no promises about

any actual products or time frames. Perhaps, by the time project

Denver evolves into actual devices the market of servers will be

completely different from today and highly-parallel accelerators will

be more important than x86-based AMD Opteron or Intel

Xeon microprocessors.

"Nvidia is a key partner for ARM and this announcement shows the

potential that partnership enables. With this architecture license,

Nvidia will be at the forefront of next generation SoC design,

enabling the Internet Everywhere era to become a reality," said

Warren East, ARM chief executive officer.

Itable workloads from the integrated APU cores onto discrete add-in

board cores, too.

AMD: APUs Will Challenge Traditional

Microprocessors.

Standalone central processing units (CPUs) for client computers will

be challenged by accelerated processing units (APUs) with integrated

graphics core, a high-ranking officer at AMD said in an interview.

APUs provide better performance because of its ability to efficiently

process both parallelized and serialized data.

"I think APUs will definitely challenge standalone CPUs. I believe

that the future of consumer as well as commercial computing environments are characterized by the ability to present a compelling

visual experience. Taking a GPU core and a CPU core and using

them together on one chip will definitely challenge standalone

CPUs," said Neal Robison, senior director of content and application.



Accelerated processing units integrate many parallel GPU processing elements as well as several "fat" x86 CPU cores that can efficiently

process typical data. Many performance-demanding applications

nowadays use parallel processing and receive benefits from both

multi-core CPUs as well as many-core CPUs. Nonetheless, there are

loads of programs that use advanced microprocessors and have no

need for GPUs.

But while APUs will confront low-cost systems, they will not

challenge and will not become part of advanced personal computerswith discrete graphics cards.

"I do not think that APUs will challenge discrete GPUs on anything,

but on the lowest-end systems. When you look at adding a discrete

GPU that enhances performance of the graphics side, it makes a huge

amount of sense as it scales [performance] on a wide amount of



applications because of the rich visual experience that everybody

expects now when they are actually using their computing device,"

added Mr. Robison.

Where is Accelerated Processing Unit located in

computer architecture?

Answer:

The CPU has been the heart of every PC since Intel¶s x86 processors

became popular over two decades ago. Yet the CPU does haveweaknesses,the greatest of which is their relatively linear data

execution. Graphics processors, by comparison, consist of many s mall

cores that execute data simultaneously. This makes it easier for them

to perform certain tasks, like video decoding and 3D graphics.

AMD outlines plans for future processors:

During its four-hour Financial Analyst Day presentation , AMD

revealed new elements of its processor roadmap spanning the next

couple of years, as well as its plans to scale beyond the current multi-core model. Intel talked about processors with "tens to hundreds of

cores" at IDF earlier this year, but AMD believes the core race is just

a repeat of the megahertz race and that adding more cores isn't the

best way to go about scaling processor performance in the future.

Instead, AMD is cooking up what it calls "Accelerated Processing

Units":



Accelerated Processing Units, or APUs, will be multi-core chips that

include any mix of processor cores and other dedicated processors.

Fusion , AMD's integrated CPU and graphics processor, is AMD's

first step in that direction. However, the company eventually intends

add more specialized cores that can handle tasks other than general-

purpose computing and graphics. AMD didn't give any specific

examples, but one could easily imagine future Fusion-like chips with

cores for physics processing, audio/video encoding, and heck, maybeeven AI acceleration.

Whatever it ends up doing, AMD says it will be able to tailor APUs

with different combinations of core types to specific markets. Fusion,

for example, will be aimed chiefly at the mobile market when it

arrives in 2009. Enthusiasts needn't worry, though: AMD says it

doesn't plan to integrate high-end GPUs and CPUs into massive

silicon fireballs, because both production costs and power envelopes

for such chips would be too high.

AMD also revealed some of its more immediate plans for the

processor market by showing off new desktop and mobile roadmaps:



APU Architecture

The term APU stands for Accelerated P rocessing U nit. At the

moment, this is a term that only AMD is using for its products. Intel¶srecently released update to its processors also qualifies as an APU;

Intel simply seems unwilling to use the definition. That¶s

understandable, since the company has been known as the world¶s

leading CPU maker for years.

An APU is simply a processor that combines CPU and GPU elements

into a single architecture. The first APU products being shipped by

AMD and Intel do this without much fuss by adding graphics

processing cores into the processor architecture and letting them

share a cache with the CPU. While both AMD and Intel are using their own GPU architectures in their new processors, the basic

concepts and reasons behind the decision to bring a GPU into the

architecture remain the same.



The desktop roadmap is more or less self-explanatory, placing the

introduction of quad-core desktop CPUs in mid-2007 and the launch

of derived dual-core models in the latter part of the year. All new

chips will have support for HyperTransport 3.0 and DDR2 memory,

and accompanying motherboards will boast PCI Express 2.0 support.

AMD apparently doesn't intend to switch sockets or move to DDR3

memory until the middle of 2008.



On the mobile front, things are a little more interesting. Early next

year, AMD will launch a new mobile chip code-named "Hawk" that

will boast lower power utilization than current Turion 64 X2 and

Mobile Sempron chips. The chip will be paired with platforms that

will have support for hybrid hard drives as well as a somewhat novel

concept dubbed hybrid graphics.

According to AMD, notebooks with hybrid graphics will include both

discrete and integrated graphics processors. When such notebooks

are unplugged, their integrated graphics will kick in and disable the

discrete GPU. As soon as the notebook is plugged back into a power

source, the discrete GPU will be switched on again, apparently

without the need to reboot. AMD says this technology will enable

notebooks to provide the "best of both worlds" in terms of

performance and battery life.



In late 2007, AMD will introduce a mobile chip dubbed Griffin that

will support split power planes and HyperTransport 3.0, meaning it'll

almost certainly be based on AMD's quad-core architecture. Griffin

will be accompanied by platforms supporting PCI Express 2.0,

DirectX 10-class integrated graphics, DisplayPort video output, and a Universal Video Decoder²essentially a dedicated video processor.

That about covers what AMD unveiled about its upcoming processors

today. The presentation did include a fair amount of discussion about

the company's financial performance and consumer electronics plans,

though; we'll fill you in on those topics a little later.

Power Management In APU:

Use of 32nm technology provides power efficiency.

Use of SOI power gating technology & core power consumption.

Use of digital power meter.

Use of less numbers of transistor

F eatures of APU:

Handles multi-core processor as well as high end graphics using a

single silicon die.

Improves data transfer rate.

Reduces power consumption.

Includes video processing & other specific acceleration.

Offers high computing capability.

The Benefits Of An APU:

AMD and Intel wouldn¶t go to the trouble of integrating a GPU into

their CPU architectures if there weren¶t some benefits to doing so,

but sometimes the benefit of a new technology seems to be focused

more on the company selling the product than the consumer.



Fortunately, the benefits of the APU are dramatic and will be noticed

by end users.

Obviously, improved performance is one advantage. The graphics

placed on current APUs are not meant to be competitive with high-

end or even mid-range discrete graphics cards, but they are better

than previous integrated graphics processors. Intel HD Graphics

3000, the fastest graphics option available on the company¶s newest

processor, is two to three times quicker than the previous Intel HD

Graphics solution, which was on the processor die but not integrated

into the architecture. This also makes it possible to include new

features, like Intel¶s QuickSync video transcoding techology.

Another advantage brought by APUs is improved power efficiency.

Integrated the GPU into the architecture makes it possible to share

resources and achieve the same results with less silicon. This meansan APU can replicate the performance of a system equipped with a

low-end discrete graphics card while using far less power. Early

benchmarks of Intel Sandy Bridge and AMD Fusion laptops make this

advantage obvious; systems equipped with these processors

have better battery life than similar system saddled with a CPU and a

separate discrete or integrated graphics processor .



Conclusion

The APU is the future of processor design. The only question at this point is the term itself. While Intel¶s new processors also fit the

definition of an APU, the term APU is only used by AMD in its

marketing. If Nvidia also decides this is a term worth using as it

develops its new processor it may have some legs. Otherwise, I

wouldn¶t be surprised if Intel uses its considerable marketshare might

to squash it.

But whatever this new generation of hardware is called five years

from now, the results are the same. APUs are here, they¶re awesome,

and they¶ll make it easier for users to enjoy media without consuming

unreasonable amounts of power.

what is an accelerated processing unit

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