Intel GMA
From Wikipedia, the free encyclopedia
intel Graphics Guide
Intel GMA
From Wikipedia, the free encyclopedia
GMA X3000 on Intel DG965WHMKR motherboard
The Intel Graphics Media Accelerator, or GMA, is Intel's current line of graphics processors (GPUs) built into various motherboard chipsets.
These integrated graphics solutions allow a computer to be built without a separate graphics card,
which can lead to dramatically lower overall costs and lower power
consumption. They are commonly found on notebook computers and low- and
mid-range desktops. They rely on the computer's main memory for storage, which imposes a performance penalty as both the CPU and GPU have to access memory over the same bus.
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[edit] History
The GMA line of GPUs replaces the earlier “Extreme Graphics”, Intel’s first series of integrated graphics chips, and Intel740 line, which were discrete units in the form of AGP cards.
The original architecture of GMA systems supported only a few
functions in hardware, and relied on the host CPU to handle at least
some of the graphics pipeline, further decreasing performance. However,
with the introduction of Intel’s 4th generation of GMA architecture
(GMA X3000) in 2006, many of the functions are now built into the
hardware, providing an increase in performance. The 4th generation of
GMA combines fixed function capabilities with a threaded array of
programmable executions units, providing advantages to both graphics
and video performance. Many of the advantages of the new GMA
architecture come from the ability to flexibly switch as needed between
executing graphics-related tasks or video-related tasks. While GMA
performance has been widely criticized in the past as being too slow
for computer games, the latest GMA generation should ease many of those concerns for the casual gamer.
Despite similarities, GMA is not based on the PowerVR technology Intel licensed from Imagination Technologies. Intel uses the low-power PowerVR MBX designs in chipsets that support their XScale
platform. With the sale of XScale in 2006, it is not clear if Intel
will continue to use PowerVR systems with their x86-based XScale
replacements.
[edit] Hardware: graphics cores
[edit] GMA 900
The GMA 900 was the first graphics core produced under Intel's Graphics Media Accelerator
product name, and was incorporated in the Intel 910G, 915G, and 915Gx
chipsets. The GMA 900 was a notable upgrade from the previous Extreme 3D
graphics processors, but was still relatively basic compared to other
graphics solutions. For example, its 3D graphics core lacks support for
hardware transform and lighting and the similar vertex shader
technologies, an important part of the 3D acceleration pipeline. It
instead emulated this functionality in software, reducing compatibility
and performance with 3D games.
The GMA 900 has four pixel pipelines running at a core clock rate of 333 MHz, and a RAMDAC
at 400 MHz. This allows it a peak pixel fillrate performance of 1333
MPixel/s. Like its predecessors (i810/815/845G), the GMA 900 has
hardware support for MPEG-2 motion compensation, color-space conversion and DirectDraw overlay.
[edit] GMA 950
The GMA 950 is Intel's second-generation Graphics Media Accelerator
graphics core. It is used in the Intel 940GML, 945G, 945GU and 945GT
system chipsets. The amount of video-decoding hardware has increased;
VLD, iDCT, and dual video overlay windows are now handled in hardware. The core clock is 400 MHz, boosting pixel fill-rate to a theoretical 1600 megapixels/s.
The GMA 950 shares the same architectural weakness as the GMA 900:
no hardware geometry processing. Neither basic (DX7) hardware transform
and lighting.[1], nor more advanced vertex shaders (DX8 and later) are handled in the GMA hardware.
[edit] GMA 3000
The 946GZ, Q965 and Q963 chipsets use GMA 3000.[2][3]
The GMA 3000 3D core is very similar to the X3000, however some
features (such as vertex shaders, or pixel shader version 3.0) may not
be supported. In addition, hardware video acceleration such as
hardware-based iDCT computation, ProcAmp (video stream independent color correction),
VC-1 decoding may not be implemented in hardware. Of the GMA
3000-equipped chipsets, only Q965 retains dual independent display
support.
[edit] GMA 3100
The G31, G33, Q33 and Q35 chipsets use the GMA 3100. The 3D core is very similar to the older GMA 950.
[edit] GMA X3000
The GMA X3000 represents a dramatic architectural change from
previous GMA iterations. Most notably, X3000's underlying 3D rendering
hardware is organized as a unified shader processor consisting of 8 scalar
execution units. Each pipeline can process video, vertex, or texture
operations. A central scheduler dynamically dispatches threads to
pipeline resources, to maximize rendering throughput (and decrease the
impact of individual pipeline stalls.) However, due to the scalar
nature of the execution units, they can only process data on a single
pixel component at a time.[4]
The processor consists of different clock domains, meaning that the
entire chip does not operate the same clock speed. This causes some
difficulty when measuring peak throughput of its various functions.
Adding to the confusion are various rules that define the IGP's
processing capabilities. Most of the time, the core is capable of 1.6
pixels and 3.2 textures per clock cycle. It has a maximum potential
pixel fill-rate of 2.0 pixels per clock, but only during a "clear"
cycle. Similarly, while it can process depth operations at 4 pixels per
clock, with texturing this falls to 3.2 pixels per clock. Resulting
theoretical fill-rates are 1067 megapixels/s and 2133 megatexel/s at the X3000's overall 667 MHz.[4]
Intel again updated the video processing capabilities of their graphics product. The X3000 features WMV9 (VC-1) video acceleration.
[edit] GMA X3100
The GMA X3100 is the mobile version of the GMA X3000 used in the Mobile 965GM chipset.
[edit] GMA X3500
GMA X3500 is the name of the version used with the G35 ("Bearlake") chipset.[5]
[edit] Table of GMA graphics cores and chipsets
This table is derived from these sources: [2] [3] [13] [4] [14] [12] [11] [7] [9] [6] [10] [15] [8]
Notes:
[edit] Software support
[edit] Apple Mac
The GMA 950 is used in all MacBooks (but not MacBook Pros), Intel-based Mac Minis and some of the older low-end intel models of the iMac, and is therefore supported by Mac OS X.[16]
[edit] FreeBSD
FreeBSD 7.0 supports all intel graphic chipsets, including
G965/Q965/GM965/GME965/GME945. Though support for G33/Q35/Q33 is
disabled due to lack of testing.[17]
Intel has had a long history of producing or commissioning open
source drivers for its graphics chips, with all chipsets dating back to
the i810 having open 2D and 3D drivers for Linux. It is the only major
graphics hardware vendor to do so: for an analysis by company see Graphics hardware and FOSS.
In August 2006, Intel added support to the open-source X.Org/XFree86 drivers for the latest 965 series that include the GMA (X)3000 core.[18] These drivers were developed for Intel by Tungsten Graphics.[19]
In May 2007, version 2.0 of the driver (xorg-video-intel) was
released, which added support for the 965GM chipset. In addition, the
2.0 driver added native video mode programming support for all chipsets
from i830 forward. This version added support for automatic video mode
detection and selection, monitor hot plug, dynamic extended and merged
desktops and per-monitor screen rotation. These features are built in
to the X.Org 7.3 X server release and will eventually be supported
across most of the open source X.Org video drivers.[20] Version 2.1, released in July 2007, added support for the G33, Q33 and Q35 chipsets.[21]
As is common for X.Org drivers on Linux, the license is a combination of GPL (for the Linux kernel parts) and MIT (for all other parts).[22]
[edit] intel_hal.so
The driver source contains references to a currently-unavailable
binary named "intel_hal.so". It is entirely optional, and the
advantages are not clear; ostensibly they are increased performance
and/or additional features. References in the open source code indicate
that it contains or contained (at least) Macrovision
support and some minor, optional 3D optimization routines. Calls to the
Macrovision code inside the binary were later removed from the 2D
driver.[23][24]
[edit] Microsoft Windows
[edit] GMA 900
This IGP is capable of running Windows Vista's Aero
interface and certified as DirectX 9 compliant. Although no WDDM driver
has been made publicly available for this chipset. This is claimed to
be due to the lack of a "hardware scheduler" in the GMA chipsets. [25]
Many owners of GMA900 hardware believed they would be able to run
Aero on their systems, as early release candidates of Vista permitted
XPDM drivers to run Aero. However, Intel contends that Microsoft's
final specs for Aero/WDDM certification did not permit releasing a WDDM
driver for GMA900 (due to issues with the hardware scheduler, as
mentioned above), so when the final version of Vista was released, no
WDDM driver was released.[26]
The last minute pulling of OpenGL capabilities from the GMA drivers for
Windows Vista leaves the large number of GMA based workstations unable
to perform basic 3D hardware acceleration with OpenGL.
[edit] GMA 950
This IGP is capable of running Windows Vista's Aero interface. Drivers have shipped with Windows Vista since mid-2006 betas.
[edit] GMA X3000
Note: T&L and Vertex Shaders 3.0 are still not supported
by Intel device drivers either in Windows XP or Windows Vista. Intel
announced in March 2007 that beta drivers would be available in June of
2007.[27] [28] On June 1st 2007 "pre-beta" (or Early Beta) drivers were released for Windows XP (but not for Vista).[29]. Beta drivers for Vista and XP were released on June 19th.[30]
Intel has released production version drivers for 32-bit and 64-bit Windows Vista that enable the Aero graphics. Intel expects to deliver DirectX 10 support in the first quarter of 2008 "if the process goes well."[31]
[edit] Modern gaming
Because many of the features of these graphics sub-systems rely on
software emulation, this can lead to 3D performance issues (slow vertex
shaders) and incompatibility with some games. The new GMA X3000 and
X3100 will seek to remedy these problems with full hardware support for
modern gaming architecture.
Intel, not oblivious to these problems, has put up a page with 'Known Issues & Solutions':
For Intel GMA Software Development concerns, questions may be made at http://softwareforums.intel.com/ISN/Community/en-US/Forums/ in the Integrated Graphics Software Development Forum.
[edit] References
- ^ Case, Loyd. Intel GMA950 Integrated Graphics Core, Extremetech, May 31, 2005.
- ^ a b c d Product brief: The Intel 946GZ Express Chipset. Retrieved on 2007-06-28.
- ^ a b c d e Intel’s Next Generation Integrated Graphics Architecture – Intel® Graphics Media Accelerator X3000 and 3000. Retrieved on 2007-06-08.
- ^ a b c Gasior, Geoff. Intel's G965 Express chipset, Tech Report, April 5, 2007.
- ^ Lars-Göran Nilsson. Fudzilla: Intel G35 graphics engine named. Retrieved on 2007-05-31.
- ^ a b c Case, Loyd. Intel GMA950 Integrated Graphics Core, Extremetech, May 31, 2005.
- ^ a b c Romanchenko, Vladimir. Intel Centrino Duo: new-generation mobility, Digital Daily, January 24, 2006.
- ^ a b [http://download.intel.com/design/mobile/datashts/30921904.pdf Mobile Intel® 945 Express Chipset Family Datasheet], Intel, accessed July3, 2007.
- ^ a b Intel® 946 Express Chipset Family Datasheet, Intel, accessed June 28, 2007.
- ^ a b Intel® 3 Series Chipsets Datasheet, Intel, accessed June 29, 2007.
- ^ a b Intel® Graphics Media Accelerator 900, Intel, accessed June 28, 2007.
- ^ a b Intel® GMA 950 Graphics Product Brief, Intel, accessed June 28, 2007.
- ^ a b c Intel Graphics - Built for mainstream Desktop and Mobile PC Users. Retrieved on 2007-06-08.
- ^ Intel® Graphics Media Accelerator X3000 and 3000 White Paper, Intel, accessed June 28, 2007.
- ^ Mobile Intel® 915PM/GM/GME/GMS and 910GML/GMLE Express Chipset Datasheet, Intel, accessed June29, 2007.
- ^ Apple's MacBook page (scroll down and click "Compare Specs")
- ^ Eric Anholt. FreeBSD cvs-src mailing list. Retrieved on 2007-07-16.
- ^ Intel Linux graphics web site
- ^ Tungsten Graphics web site
- ^ Free software drivers for the Intel 965GM Express Chipset
- ^ Eric Anholt. X.Org mailing list: xf86-video-intel 2.1.0. Retrieved on 2007-07-09.
- ^ Open Source Graphics Drivers from Intel — Licence
- ^ LKML thread about intel_hal.so
- ^ X.Org ML thread about intel_hal.so
- ^ Intel excuse for no GMA900 WDDM driver: no "HW Scheduler" no driver, Beyond3D, October 26, 2006.
- ^ Intel's response to 915G WDDM requests
- ^ Intel G965 drivers Announce
- ^ G965 drivers Forum Discussion
- ^ Pre-Beta XP Drivers
- ^ [1]
- ^ Intel G35 chipsets will not support DirectX 10 until 2008
[edit] See also
[edit] External links
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