AMD CrossFire (also known as CrossFireX) is a brand name for the multi-
GPU
A graphics processing unit (GPU) is a specialized electronic circuit designed to manipulate and alter memory to accelerate the creation of images in a frame buffer intended for output to a display device. GPUs are used in embedded systems, mobi ...
technology by
Advanced Micro Devices
Advanced Micro Devices, Inc. (AMD) is an American multinational semiconductor company based in Santa Clara, California, that develops computer processors and related technologies for business and consumer markets. While it initially manufact ...
, originally developed by
ATI Technologies
ATI Technologies Inc. (commonly called ATI) was a Canadian semiconductor industry, semiconductor technology corporation based in Markham, Ontario, Markham, Ontario, that specialized in the development of graphics processing units and chipsets. Fo ...
. The technology allows up to four
GPU
A graphics processing unit (GPU) is a specialized electronic circuit designed to manipulate and alter memory to accelerate the creation of images in a frame buffer intended for output to a display device. GPUs are used in embedded systems, mobi ...
s to be used in a single computer to improve graphics performance.
Associated technology used in mobile computers with external graphics cards, such as in
laptop
A laptop, laptop computer, or notebook computer is a small, portable personal computer (PC) with a screen and alphanumeric keyboard. Laptops typically have a clam shell form factor with the screen mounted on the inside of the upper li ...
s or notebooks, is called
AMD Hybrid Graphics
AMD Hybrid Graphics technology, is a collective brand from AMD for its Radeon line of discrete and integrated GPU, promoting higher performance and productivity while saving energy consumption in GPUs.
The technology previously applied to selec ...
.
The CrossFire brand name was retired by AMD in September 2017, however the company continues to develop and support the technology for
DirectX 11
Microsoft DirectX is a collection of application programming interfaces (APIs) for handling tasks related to multimedia, especially game programming and video, on Microsoft platforms. Originally, the names of these APIs all began with "Direct", ...
applications. For
DirectX 12
Microsoft DirectX is a collection of application programming interfaces (APIs) for handling tasks related to multimedia, especially game programming and video, on Microsoft platforms. Originally, the names of these APIs all began with "Direct", ...
applications, AMD has the mGPU (also known as multi-GPU) branding, with the difference being that software developers must create mGPU compatible profiles for their applications where before AMD created the profiles for DirectX 11 applications.
Configurations
First-generation
CrossFire was first made available to the public on September 27, 2005. The system required a CrossFire-compliant
motherboard
A motherboard (also called mainboard, main circuit board, mb, mboard, backplane board, base board, system board, logic board (only in Apple computers) or mobo) is the main printed circuit board (PCB) in general-purpose computers and other expand ...
with a pair of ATI
Radeon
Radeon () is a brand of computer products, including graphics processing units, random-access memory, RAM disk software, and solid-state drives, produced by Radeon Technologies Group, a division of AMD. The brand was launched in 2000 by ATI Tech ...
PCI Express
PCI Express (Peripheral Component Interconnect Express), officially abbreviated as PCIe or PCI-e, is a high-speed serial computer expansion bus standard, designed to replace the older PCI, PCI-X and AGP bus standards. It is the common ...
(PCIe) graphics cards. Radeon
x800s, x850s, x1800s and x1900s came in a regular edition, and a "CrossFire Edition" which has "master" capability built into the hardware. "Master" capability is a term used for 5 extra image compositing chips, which combine the output of both cards. One had to buy a Master card, and pair it with a regular card from the same series. The Master card shipped with a proprietary
DVI
Digital Visual Interface (DVI) is a video display interface developed by the Digital Display Working Group (DDWG). The digital interface is used to connect a video source, such as a video display controller, to a display device, such as a comp ...
Y-dongle, which plugged into the primary DVI ports on both cards, and into the
monitor
Monitor or monitor may refer to:
Places
* Monitor, Alberta
* Monitor, Indiana, town in the United States
* Monitor, Kentucky
* Monitor, Oregon, unincorporated community in the United States
* Monitor, Washington
* Monitor, Logan County, West ...
cable. This dongle serves as the main link between both cards, sending incomplete images between them, and complete images to the monitor. Low-end Radeon
x1300 and x1600 cards have no "CrossFire Edition" but are enabled via software, with communication forwarded via the standard
PCI Express
PCI Express (Peripheral Component Interconnect Express), officially abbreviated as PCIe or PCI-e, is a high-speed serial computer expansion bus standard, designed to replace the older PCI, PCI-X and AGP bus standards. It is the common ...
slots on the motherboard. ATI currently has not created the infrastructure to allow
FireGL
AMD FirePro was AMD's brand of graphics cards designed for use in workstations and servers running professional Computer-aided design (CAD), Computer-generated imagery (CGI), Digital content creation (DCC), and High-performance computing/ ...
cards to be set up in a CrossFire configuration. The "slave" graphics card needed to be from the same family as the "master".
An example of a limitation in regard to a Master-card configuration would be the first-generation CrossFire implementation in the Radeon X850 XT . Because it used a compositing chip from
Silicon Image
Silicon Image is a provider of semiconductors for the mobile, consumer electronics and personal computers (PCs). It also manufactures wireless and wired connectivity products used for high-definition content. The company’s semiconductor and IP p ...
(SiI 163B TMDS), the maximum resolution on an X850 CrossFire setup was limited to 1600×1200 at 60 Hz, or 1920×1440 at 52 Hz. This was considered a problem for
CRT owners wishing to use CrossFire to play games at high resolutions, or owners of Widescreen
LCD monitors. As many people found a 60 Hz refresh rate with a CRT to strain one's eyes, the practical resolution limit became 1280×1024, which did not push CrossFire enough to justify the cost. The next generation of CrossFire, as employed by the X1800 Master cards, used two sets of compositing chips and a custom double density dual-link DVI Y-dongle to double the bandwidth between cards, raising the maximum resolution and refresh rate to far higher levels.
Second-generation (Software CrossFire)
When used with ATI's "CrossFire
Xpress 3200
The Xpress 3200 is a revision of the Xpress 200 computer chipset released by ATI. The chipset supports AMD64 processors for Socket 939 and Socket AM2.
History of the Xpress 3200 chipset
The Radeon Xpress chipset was designed by ATI to enter the ...
" motherboard chipset, the "master" card is no longer required for every "CrossFire Ready" card (with the exception of the Radeon X1900 series). With the CrossFire Xpress 3200, two normal cards can be run in a Crossfire setup, using the PCI Express bus for communications. This is similar to X1300 CrossFire, which also uses PCI Express, except that the Xpress 3200 had been built for low-latency and high-speed communication between graphics cards. While performance was impacted, this move was viewed as an overall improvement in market strategy, because Crossfire Master cards were expensive, in high demand, and largely unavailable at the retail level.
Although the CrossFire Xpress 3200 chipset is indeed capable of CrossFire through the PCI Express bus for every Radeon series below the X1900s, the driver accommodations for this CrossFire method have not yet materialized for the X1800 series. ATI has said that future revisions of the Catalyst driver suite will contain what is required for X1800
dongle
A dongle is a small piece of computer hardware that connects to a port on another device to provide it with additional functionality, or enable a pass-through to such a device that adds functionality.
In computing, the term was initially synonym ...
less CrossFire, but has not yet mentioned a specific date.
Third-generation (CrossFireX)
![R700 interconnect](https://upload.wikimedia.org/wikipedia/commons/e/ee/R700_interconnect.svg)
With the release of the
Radeon
Radeon () is a brand of computer products, including graphics processing units, random-access memory, RAM disk software, and solid-state drives, produced by Radeon Technologies Group, a division of AMD. The brand was launched in 2000 by ATI Tech ...
X1950 Pro (
RV570 GPU), ATI has completely revised CrossFire's connection infrastructure to further eliminate the need for past Y-
dongle
A dongle is a small piece of computer hardware that connects to a port on another device to provide it with additional functionality, or enable a pass-through to such a device that adds functionality.
In computing, the term was initially synonym ...
/Master card and slave card configurations for CrossFire to operate. ATI's CrossFire connector (CrossFire Bridge Interconnect, or CFBI link) is now a ribbon-like connector attached to the top of each graphics adapter, similar to nVidia's
SLI bridges, but different in physical and logical natures.
As such, Master Cards no longer exist, and are not required for maximum performance. Two dongles can be used per card; these were put to full use with the release of CrossFireX. Radeon HD 2900 and HD 3000 series cards use the same ribbon connectors, but the HD 3800 series of cards only require one ribbon connector, to facilitate CrossFireX. Unlike older series of Radeon cards, different HD 3800 series cards can be combined in CrossFireX, each with separate clock control.
Since the release of the codenamed ''Spider'' desktop platform from AMD on November 19, 2007, the CrossFire setup has been updated with support for a maximum of four video cards with the
790FX chipset; the CrossFire branding was then changed to "ATI CrossFireX". The setup, which, according to internal testing by AMD, will bring at least 3.2x performance increase in several games and applications which required massive graphics capabilities of the computer system, is targeted to the enthusiast market.
A later development to the CrossFire infrastructure includes a dual GPUs with on-board PCI Express bridge that was released in early 2008, the Radeon HD 3870 X2 and later in Radeon HD 4870 X2 graphics cards, featuring only one CrossFire connector for dual card, four GPU scalability. When using two GPUs on board the same system, the HDMI ports on the GPUs cannot both work at the same time.
An earlier CrossFireX and chipset compatibility chart is shown here:
The latest compatibility charts, as of April 2014, shows AMD 890, 990 and A75 chipsets—and many Intel chipsets including Z68 and X79 chipsets—as being compatible with CrossFireX; they also show which GPU cards may be paired with an external bridge (HD 7750, HD 5750, HD 4350, HD 4550, HD 4650, HD 4670 cards may be paired without an external bridge, though the charts also indicate that some models manufactured by other than AMD may still require the bridge).
Fourth generation (XDMA)
![AMD DirectGMA](https://upload.wikimedia.org/wikipedia/commons/d/df/AMD_DirectGMA.svg)
The Radeon R9 290 and R9 290X graphics cards (released on October 24, 2013 and based on
Graphics Core Next 1.1 "Volcanic Islands") as well as GPUs using newer versions of GCN no longer have bridging ports. Instead, they use ''XDMA'' to open a direct channel of communication between the multiple GPUs in a system, operating over the same PCI Express bus which is used by AMD Radeon graphics cards.
PCI Express 3.0 lanes provide up to 17.5 times higher bandwidth (15.754 GB/s for a ×16 slot) when compared to current external bridges (900 MB/s), rendering the use of a CrossFire bridge unnecessary. Thus, XDMA was selected for greater GPU interconnection bandwidth demands generated by
AMD Eyefinity
AMD Eyefinity is a brand name for AMD video card products that support multi-monitor setups by integrating multiple (up to six) display controllers on one GPU. AMD Eyefinity was introduced with the Radeon HD 5000 Series "Evergreen" in September 2 ...
, and more recently by
4K resolution
4K resolution refers to a horizontal display resolution of approximately 4,000 pixels. Digital television and digital cinematography commonly use several different 4K resolutions. In television and consumer media, 38402160 (4K Ultra-high-definitio ...
monitors. Bandwidth of the data channel opened by XDMA is fully dynamic, scaling itself together with the demands of the game being played, as well as adapting to advanced user settings such as
vertical synchronization
Analog television is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness, colors and sound are represented by amplitude, phase and frequency of an analog s ...
(vsync).
Additionally, some newer cards are capable of pairing with
7000-series cards based on the
Graphics Core Next 1.0 "Southern Islands" architecture. For example, an R9-280X card can be used in a CrossFireX setup together with a HD 7970 card, largely due to them being the same product at different clock rates.
GPUOpen offers some MIT-licensed source-code for DirectGMA applications with multiple AMD GPUs in conjunction with Direct3D 11, OpenGL and OpenCL: https://github.com/GPUOpen-LibrariesAndSDKs/DirectGMA_P2P
Hybrid CrossFireX (dual graphics)
There is also a "hybrid" mode of CrossFireX that combines on-board graphics using the AMD
northbridge architecture with select graphic cards,
for increased performance. The current generation is called Hybrid CrossFireX and is available for motherboards with integrated AMD chipsets in the
7 and
8 series
GPU
A graphics processing unit (GPU) is a specialized electronic circuit designed to manipulate and alter memory to accelerate the creation of images in a frame buffer intended for output to a display device. GPUs are used in embedded systems, mobi ...
s, referred to as
Hybrid CrossFireX.
This combination results in power-savings when simple or 2D graphics are used and performance increases of 25% to over 200% in 3D graphics over using a non CrossFire option. As of March 2012, it appears that this is now called "
AMD Radeon Dual Graphics" and means using A-series
Fusion APUs together with video cards.
Comparisons to Nvidia SLI
Similarities
In some cases CrossFire doesn't improve 3D performance – in some extreme cases, it can lower the framerate due to the particulars of an application's coding. This is also true for Nvidia's SLI, as the problem is inherent in multi-GPU systems. This is often witnessed when running an application at low resolutions.
When using CrossFire with
AFR AFR may refer to:
* ''AFR'' (film), a 2007 film
* Afrikaans language, ISO-639 code
* Air France, ICAO code
* Air–fuel ratio
* Armed Forces Radio
* Alternate frame rendering
* American Family Radio
* American Film Renaissance
* American flag rug ...
, the subjective framerate can often be lower than the framerate reported by benchmarking applications, and may even be poorer than the frame rate of its single-GPU equivalent. This phenomenon is known as
micro stuttering __notoc__
Micro stuttering is a term used in computing to describe a quality defect that manifests as irregular delays between frames rendered by the GPU(s), causing the instantaneous frame rate of the longest delay to be significantly lower than ...
and also applies to SLI since it is inherent to multi-GPU configurations. AMD CrossFireX, and NVIDIA SLI setups both require bridges, and a power supply unit (PSU) capable of supplying enough power to the GPUs. 6 pin (75 watt 3+3, becoming rare now), 8 pin (150 watt 4+4), and 16 pin (300 watt 8+8) power plugs are all common in today's graphics cards.
Advantages
CrossFire can be implemented with GPU cards of the same generation, and manufacture (this is compared to Nvidia's SLI, which generally only works if all cards have the same GPU, and brand). This allows buyers who have varying budgets over time to purchase different cards and still get the benefits of increased performance. With the latest generation cards, they will only crossfire with other cards in their sub series. For example, GPU in the same series can be crossfired with each other. So a 5800 series GPU (e.g. a 5830) can run together with another 5800 series GPU (e.g. 5870). However, GPUs not in the same hundred series cannot be crossfired successfully (e.g. a 5770 cannot run with a 5870). The only exception is that the HD 7870 XT cards can be used with a HD 7900 series GPU (e.g., a 7950) in a crossfire configuration because they feature the same GPU.
AMD CrossFire, and SLI configurations can run many monitors of varying size and resolutions. Both SLI , and CrossFire setups only allow up to four 8K (7680x4320) monitors, or eight 4K monitors (3840x2160). Each monitor requires its own dedicated graphics card (except for 4K, and standard HD), in that case up to two monitors can be on one dedicated graphics card.
Disadvantages
Major downside of CrossFire is that it works only in fullscreen mode, requiring extrinsic support for software or games when run in borderless/windowed mode.
The
first generation CrossFire implementations (the Radeon X800 to X1900 series) require an external y-cable/
dongle
A dongle is a small piece of computer hardware that connects to a port on another device to provide it with additional functionality, or enable a pass-through to such a device that adds functionality.
In computing, the term was initially synonym ...
to operate in CrossFire mode due to the PCI Express bus not being able to provide enough bandwidth to run CrossFire without losing a significant amount of performance.
See also
*
Scalable Link Interface
Scalable Link Interface (SLI) is a brand name for a deprecated multi-GPU technology developed by Nvidia for linking two or more video cards together to produce a single output. SLI is a parallel processing algorithm for computer graphics, meant ...
*
Intel Xe Link
*
MultiChrome
Chrome 20 Series is a graphics accelerator by S3 Graphics, the successor of GammaChrome S18.
Overview
The Chrome 20 series was introduced on March 11, 2005, with the Chrome S25 and Chrome S27 as launch products. Similar to the GammaChrome S18 ...
*
Comparison of ATI chipsets
This is a comparison of chipsets, manufactured by ATI Technologies.
For AMD processors
Comparison of Northbridges
Comparison of Southbridges
For Intel processors Comparison of Northbridges
Comparison of Southbridges
See also
* List o ...
*
Comparison of AMD chipsets
This is an overview of chipsets sold under the AMD brand, manufactured before May 2004 by the company itself, before the adoption of open platform approach as well as chipsets manufactured by ATI Technologies after October 2006 as the completio ...
*
Micro stuttering __notoc__
Micro stuttering is a term used in computing to describe a quality defect that manifests as irregular delays between frames rendered by the GPU(s), causing the instantaneous frame rate of the longest delay to be significantly lower than ...
*
Hybrid CrossFireX
*
Multi-chip module
A multi-chip module (MCM) is generically an electronic assembly (such as a package with a number of conductor terminals or "pins") where multiple integrated circuits (ICs or "chips"), semiconductor dies and/or other discrete components are int ...
(MCM)
References
External links
*
Hardocp.com's CrossFire previewSlashdot coverage on the release of the system
{{DEFAULTSORT:CrossFire
ATI Technologies
Advanced Micro Devices technologies