Integrated Graphics Processor

Overview
Stating basics, every personal computer that's currently sold requires some form of CPU, motherboard, memory, storage, and graphics that output to a display. These components are common to both desktop and laptop computers.

Graphics can take one of two forms: integrated or discrete. Integrated graphics refer to a GPU (graphics processing unit) that's literally part of the motherboard, integrated at the silicon level, whereas discrete graphics, more powerful in nature, use a slot-in board to connect up to a motherboard, usually via a conduit that's called PCI-Express.

This TekSpek focuses on integrated graphics and describes the options that are presently available to consumers.

IGPs
Modern IGPs tend to be based on technology that's first debuted with more-powerful discrete add-in cards. Out of the three companies that dominate the GPU market: Intel, AMD, and NVIDIA, only the latter two produce discrete, high-end GPUs, however.

In its most primitive form, an IGP (Integrated Graphics Processor) is tasked with displaying text, images, and video in various resolutions and via multifarious outputs, including choices between D-Sub (analogue), DVI, HDMI, and DisplayPort. An IGP-equipped motherboard may feature one or two display outputs but not all - not concurrently, at least.

As IGPs are integrated into the motherboard's silicon, where overall power-draw and cooling are important criterions, they cannot be as large and powerful as discrete cards. That's why IGP engineers sensibly pare-down the performance and transistor-count but try to keep the rudimentary features intact.

IGPs, too, tend not to ship with specific memory attached to them, as do discrete cards. Rather, the frame-buffer - also known as memory - is harnessed from the system, and chipsets with high-bandwidth memory support tend to offer a slightly better IGP experience.

Technologies
As of July 2009, Intel, NVIDIA and AMD have chipsets featuring DX10 graphics, the ability to help decode high-definition content such as found on Blu-ray discs, and a number of digital outputs by which the video is transferred to external displays.

The following table lists the best IGPs on offer from the three companies, together with their vital statistics.

The three leading IGPs have a broadly similar feature-set and are all able to run Microsoft Vista's Aero interface, which uses 3D power to draw a cleaner, prettier-looking graphical interface for the operating system. They, however, vary on how much power they can allocate for gaming purposes. NVIDIA and ATI are both comfortably faster than Intel's X4500HD, as shown by the Quake 4 benchmarks.

Bear in mind that no present IGP is able to render modern, cutting-edge games - Call of Duty 5 and Far Cry 2 being such examples - at a sensible resolution and at average frame-rate in excess of 30fps.

As manufacturing processes become more efficient and present add-in boards' architectures are leveraged for IGP usage, we expect performance to increase further, but design and thermal constraints will ensure that they won't match discrete cards' performance. As a comparison, a £60 Radeon HD 4730 produces 900GFLOPs of performance, which is almost 20x the best IGP's.

The market
Although Intel does not currently manufacture discrete graphics cards, relying instead on including IGPs with a wide variety of chipsets for both desktop and notebook computers, it commands the lion's share of total GPU shipments.

Industry analyst Jon Peddie estimates that in Q4 2008 a total of 72.35m GPUs were shipped. Intel, NVIDIA, and ATI made up 97.8 per cent of shipments, with Intel enjoying a 47.8 per cent market share, followed by NVIDIA's 30.7 per cent and AMD's 19.3 per cent.

Intel's share of the IGP market, therefore, is even greater, totalling some 70 per cent, according to recent research carried out by industry analysts Gartner. This situation is set to continue because Intel, as the leading producer of consumer CPUs, has an established track record of bundling in IGPs with a wide variety of CPU-supporting motherboards - be they for desktop or mobile computers.

The future
It is well-documented that IGPs attached to a motherboard's chipset, which make up the entire market right now, will be phased out completely by 2012. That does not mean that IGPs will disappear, though. Rather, both Intel and AMD will integrate IGPs directly on to the CPU.

The motherboard-to-CPU IGP transition will start as soon as Q4 2009, when Intel will debut a range of chips that will integrate graphics on to the CPU package but will do so on a separate die, with both the IGP and 'chip' connected together by a high-speed link. These new CPUs, currently known by the codename Clarkdale, will have dual-core CPU processing allied with basic graphics that are akin to the present X4500HD. AMD, too, will bring together the CPU and IGP, and the first chips are currently scheduled for 2010.

Summary
The graphics that power the display from your computer can be either integrated on to the motherboard or provided by a more-powerful add-in board. Integrated graphics (IGPs) are currently manufactured by Intel, NVIDIA, and AMD, to provide basic 2D and 3D feature-sets.

The best IGPs provide assistance in decoding high-definition content such as Blu-ray and have provision for an eclectic range of display outputs. 3D performance, however, is still an order of magnitude below what even a £60 discrete card provides.

Come 2010 and IGPs will be moved from being integrated into the motherboard to the CPU. This move won't necessarily increase IGP performance, however, but it should lead to cheaper-to-produce systems - a point that's particularly relevant for budget desktop and notebook computers.