Radeon R200

ATIGPU
name = "Radeon 8500 - 9250 Series"
codename = Chaplin


created = Late 2001
entry = 9200SE
midrange = 9000, 9200, 9250, 8500LE/9100
highend = 8500
d3dversion = 8.1, Shader Model 1.4

AMD chipsets
Table name=Radeon R200-based chipsets
CPU= Pentium M, Pentium 4-M
Socket=Socket 478, Socket 479
Desktop=y
Value=9000 Pro IGP
Mainstream=9000/9100 IGP
Performance=9100 Pro IGP
Enthusiast=
Date=June 23, 2003
May 5, 2004 (9000/9100 Pro IGP)
Predecessor=Radeon 300/Mobility Radeon 7000 series IGP
Successor=Radeon Xpress 200

The Radeon R200 is the second generation of Radeon graphics chips from ATI Technologies. It was the core that marked out ATI from other failing graphics chip companies of the period and put it on a competitive level with nVIDIA.

The line features 3D acceleration based upon Direct3D 8.0 and OpenGL 1.3, a major improvement in features and performance compared to the preceding Radeon R100 design. The processors also include 2D GUI acceleration, video acceleration, and multiple display outputs. "R200" refers to the development codename of the initially released GPU of the generation. It is the basis for a variety of other succeeding products.

Flagship product

ATI's first DirectX 8 card was the Radeon 8500, launched in October 2001. In early 2002, ATI launched the Radeon 8500LE (re-released later as the Radeon 9100), an identical chip with a lower clock speed and slower memory. Whereas the full 8500 was clocked at 275 MHz core and 275 MHz RAM, the 8500LE was clocked more conservatively at 250 MHz for the core and 200 or 250 MHz for the RAM. Both video cards were first released in 64 MiB DDR SDRAM configurations; the later 128 MiB Radeon 8500 boards received an extra performance boost resulting from a memory interleave mode.

In November 2001 was the release of the All-In-Wonder Radeon 8500 DV, with 64 MiB and a slower clock speed like the 8500LE. In 2002, three 128 MiB cards were rolled out, the Radeon 8500, 8500LE, and the All-In-Wonder Radeon 8500 128 MB, which was clocked at full 8500 speeds and had a few less features than the AIW 8500 DV.

Architecture

Radeon 8500 had a similar fundamental architecture as the other cards of the time; consisting of 4 pixel units, each with 2 texture units, along with DirectX 8.1 vertex and pixel shaders. The 2 vertex shaders were called Charisma Engine II, and offered excellent performance for both the new vertex shader programs and legacy DirectX 7 hardwired T&L. The "R200" core was more capable with regards to advanced pixel and vertex shading when compared to the competition at the time (GeForce 3 and 4 Ti), supporting DirectX 8.1 (pixel shader 1.4) with Pixel Tapestry II. R200 also had the most advanced memory bandwidth saving hardware of the time onboard, the next version of ATI's innovative HyperZ, HyperZ II. The chip was capable of dual-monitor display, through the Hydravision technology. Finally, R200 was equipped with Video Immersion II, ATI's advanced video decoding engine with high quality hardware deinterlacing. A DVI-I to component conversion connector was available for home theater enthusiasts.

R200 introduced pixel shader version 1.4, a significant revision to the 1.x pixel shader design. Whereas PS1.2 and 1.3 were just improvements to PS1.1, PS1.4 changed things around quite significantly. Notable instructions include "phase", "texcrd", and "texld". The phase instruction allows a shader to operate on two separate "phases" (2 passes through the hardware), effectively doubling the maximum number of texture addressing and arithmetic instructions, and potentially allowing the number of passes required for an effect to be reduced. This allowed not only more complicated effects, but can also allow a speed boost by utilizing the hardware more efficiently. The "texcrd" instruction moves the texture coordinate values of a texture into the destination register, while the "texld" instruction will load the texture at the coordinates specified in the source register to the destination register.

While R200 lost a texture unit per pipeline compared to R100's 2x3 architecture, R200's pipelines were far more robust. Each could address a total of 6 texture layers in a single pass if the application was coded to do so. The chip achieved this by a method commonly known as ‘loop-back’. Increasing the flexibility in the number of textures allowed per pass reduced the number of times the card was forced into ‘multi-pass rendering’, a performance draining scenario which increases both the geometry required for the scene (by needing to recalculate the entire scene for the number of times it is passed) and the external memory bandwidth used. Therefore, the chip's overall efficiency and performance was increased by enabling more textures to be addressed per pass. Testing using Serious Sam "The Second Encounter" showed a 16 % performance increase at 1600x1200 resolution with quad texturing and bilinear filtering (in comparison with dual and triple texturing).

Features

With Radeon 256 ATI had introduced their take on anisotropic filtering, using a method called "RIP" mapping. RIP mapping is not technically accurate anisotropic filtering, but it offers a very similar effect while significantly reducing performance impact. Unfortunately, their technique was only functional in combination with bilinear filtering. The implementation was also quite angle dependent, meaning that the texture had to be at a certain angle to the viewport or it would not be sharpened. Of course this reduced the computational load, but it also made it possible to see textures that were merely bilinear filtered right beside nearby sharpened textures. Radeon 8500 uses a similar technique, but now improved with a higher use of trilinear filtering and some other refinements to improve quality while still maintaining excellent performance. When anisotropic was enabled on 8500, the boundaries between mip maps, normally easily seen when using bilinear filtering instead of trilinear, were fairly well hidden and the anisotropic mode greatly improves texture sharpness at medium to long distances. Still, the remaining angle dependency and forced-bilinear were controversial from a quality standpoint. NVIDIA's GeForce 4 Ti series offered a far more accurate anisotropic implementation, but it also carried with it a heavy performance hit.

True (trilinear) anisotropic filtering on the Radeon 8500 can be enabled with third party tools such as ATI Tray Tools.

The 8500 had ATI's first implementation of a hardware-accelerated tessellation engine, called "Truform", which could add polygons to 3D models and smooth them out. The technology required developer support; unfortunately "Truform" was not ideal for all 3D rendering scenarios and had a tendency to round out objects undesirably. As a result of lack of adoption, ATI dropped "TruForm" support from its future hardware, but again added hardware-based tessellation support to their R600 line, albeit no longer under the name "TruForm".

Performance

Radeon 8500's biggest disappointment was its initial driver release. At launch, the card's performance was below expectations. Initial drivers were very buggy and did not support every feature that it was supposed to be capable of. The chip's anti-aliasing support was only functional in Direct3D, and was very slow at that. In many games the early drivers did not function perfectly, displaying strange issues such as polygon misplacement and flashing textures. nVidia released their Detonator4 driver pack on the same day as most web sites previewed the Radeon 8500, and nVidia's drivers at the time were of substantially better quality, and they also significantly boosted the GeForce 3's performance.

Worse still, several benchmark sites discovered that the real performance of the Radeon 8500 in some tests was lower than benchmarks reflected. Reviewers discovered that ATI was detecting the executable Quake3.exe and forcing the texture filtering quality to much lower than normally produced by the card. HardOCP was the first hardware review web site to bring the issue to the community, and proved its existence by renaming all instances of "Quake" in the executable to "Quack." [Bennett, Kyle. [http://www.hardocp.com/article.html?art=MTEx Optimizing or Cheating Radeon 8500 Drivers] , Hard OCP, October 23, 2001.] The result was much improved image quality, but lower performance.

Still, even with the Detonator4 drivers, the Radeon 8500 was able to outperform the GeForce 3 (which the 8500 was intended to compete against) and in some circumstances its faster revision, the Ti500, the higher clocked derivative Nvidia had rolled out in response to the R200 project. In addition, updated drivers helped to close the performance gap between the 8500 and the Ti500, while the 8500 was also significantly less expensive and offered additional multimedia features such as dual-monitor support. Though the GeForce 3 Ti200 did become the first DirectX 8.0 card to offer 128 MiB of video memory, instead of the common 64 MiB norm for high-end cards of the time, it turned out that the GeForce 3's limitations prevented it from taking full advantage of it, while the Radeon 8500 was able to more successfully exploit that potential.

In early 2002, to compete with the cheaper GeForce 3 Ti200 and GeForce 4 MX 460, ATI launched the slower-clocked 8500LE (later rename as 9100) which became popular with OEMs and enthusiasts due to its lower price, and overclockability to 8500 levels. Though the GeForce 4 Ti 4600 took the performance crown, it was a top line solution that was priced almost double that of the Radeon 8500 (MSRP of $350-399 versus $199 USD), so it didn't offer direct competition. With the delayed release of the potentially competitive GeForce 4 Ti 4200, plus ATI's initiative in rolling out 128 MiB versions of the 8500/LE kept the R200 line popular among the mid-high performance niche market. The greater features of the All-In-Wonder (AIW) Radeon 8500 DV and the AIW Radeon 8500 128 MB proved superior to Nvidia's Personal Cinema equivalents which used the faster GeForce 4 Ti 4200.

Refresh

A new high-end refresh part, the 8500XT (R250) was supposedly in the works, ready to compete against the GeForce 4 Ti line, particularly the top line Ti 4600 (which retailed for an MSRP of $350-399 USD). Prerelease information touted a 300 MHz core and RAM clock speed for the "R250" chip.

A Radeon 8500 running at 300 MHz clock speeds would have hardly defeated the GeForce 4 Ti4600, let alone a newer card from NVIDIA. At best it could have been a better performing mid-range solution than the lower-complexity Radeon 9000 (RV250, see below), but it would also have cost more to produce and would have been poorly suited to the Radeon 9000's dual laptop/desktop roles due to die size and power draw. Notably, enthusiasts found that Radeon 8500 and Radeon 9000 could not reliably overclock to 300 MHz without additional voltage, so undoubtedly R250 would have had similar issues because of its greater complexity and equivalent manufacturing technology, and this would have resulted in poor chip yields, and thus, higher costs. [http://www.xbitlabs.com/articles/video/display/radeon8500-overclocking.html] [http://www.pcstats.com/articleview.cfm?articleID=953]

ATI, perhaps mindful of what had happened to 3dfx when they took focus off their "Rampage" processor, abandoned the R250 refresh in favor of finishing off their next-generation DirectX 9.0 card which was released as the Radeon 9700. This proved to be a wise move, as it enabled ATI to take the lead in development for the first time instead of trailing NVIDIA. The new Radeon 9700 flagship, with its next-generation architecture giving it unprecedented features and performance, would have been superior to any R250 refresh, and it easily took the performance crown from the Ti4600. In order to counter the price-performance leader Ti4200, ATI released the DirectX 9.0 cards Radeon 9500 and 9600.

Mainstream Line

The Radeon 9000 (RV250) was launched alongside the 9700 (the new flagship part for ATI). This chip dropped one of the two texture units, the "TruForm" unit, Hierarchical-Z, and one of the two vertex units, bringing the configuration down to a 4x1 pixel/texture pipeline layout. It was not just cut down, however, but was actually refined as well. The texture cache was doubled in size to 4 KiB, improving a serious inefficiency in R200. Because of this, performance was still quite competitive, considering that the larger "R200" chips were more expensive and more power consuming.

In games, the Radeon 9000 performed around the same as the highly-refined "NV17" used on GeForce 4 MX 440. Its main advantage over the MX 440 was that it had a full DirectX 8.1 vertex and pixel shader implementation. While the 9000 was not quite as fast as the 8500LE or the Nvidia GeForce 3 Ti200, two cards that previously occupied the position below the GeForce 3 Ti500 and the full Radeon 8500, the 8500LE and Ti200 were slated to be discontinued. The Radeon 9000 succeeded the Radeon 7500 (RV200) in the mainstream market segment, with the latter being moved to the budget segment. The Radeon 9000 was the first mass market DirectX 8 compliant solution and had respectable speed in such applications, and Nvidia would not have a answer until the GeForce FX 5200. While the FX 5200 had DirectX 9 support, it could not manage decent performance in even DirectX 8 tasks. ATI eventually rolled out the Radeon 9600 SE to counter the FX 5200.

A later version of the 9000 was the 9200 (RV280), which, aside from supporting AGP-8X, was identical. However, there was a cheaper version, the 9200SE, which only had a 64-bit memory bus. Another board, called the Radeon 9250 was launched in summer 2004, being simply a lower-clocked variant of RV280. It was usually equipped with more RAM than the Radeon 9200 cards though (128 MiB or even 256 MiB), taking advantage of the low-cost of slow-clock high-density DDR SDRAM, a popular trend at the time. Radeon 9250 is also available as a PCI card.

The RV250 and RV280, despite able to only support up to DirectX 8 features, were nonetheless labeled as 9xxx. In order to distinguish, the box packaging for the RV2xx series was advertised as "DirectX 9.0 compatible", while the R300 series was labeled as "DirectX 9.0 compliant". Many game titles require Pixel Shaders that supported DirectX 9.0 had an option to downgrade to using DirectX 8.0 shaders.

Mobility

The derivative Mobility Radeon 9000 was launched in early summer 2002 and generated more press than its desktop counterpart since it was the first DirectX 8 laptop chip. It far outperformed the competition at the time (nVidia GeForce 2 Go), was more feature-rich than the GeForce 4 Go, and had advanced power-saving technologies incorporated. It helped to maintain ATI's lead in the mobile market established by the previous Mobility Radeons. As another first ATI had the new Mobility 9000 ready to ship in several OEM models within days of its announcement. In late 2002, Nvidia rolled out the GeForce4 4200 Go (NV28M), but though that was based of the GeForce 4 Ti and significantly faster, it lacked power-saving circuitry and caused problems for notebook manufacturers, especially with regards to heat and battery life so it was discontinued early. Consequently, the Mobility Radeon 9000 dominated the high-end laptop market.

A Mobility Radeon 9200 later followed as well, derived from the desktop 9200.

Models

Drivers

UNIX-Related Operating Systems

ATI has released no driver support for BSD based operating systems, however they do provide drivers for the X Window System running on Linux. Despite this, newer ATI Catalyst driver for Linux X Window System does not offer support for any R200 or older architecture product. Users are referred to using older drivers for older kernels, or the open source "radeon" driver for newer kernels. The PowerPC-based Mac mini and iBook G4, which run on Mac OS X, were supplied with Radeon 9200 cards.

Some segments of the Linux user community, which prefer to avoid the IP-encumbered ATI drivers due to stability and long term maintainability reasons, still prefer the R200-based chips, as they are among the fastest modern video cards with stable open source 3D drivers.

Windows Drivers

This series of Radeon graphics cards is supported by AMD under Microsoft Windows operating systems including Windows XP (except x64), Windows 2000, Windows Me, and Windows 98. Other operating systems may have support in the form of a generic driver that lacks complete support for the hardware. Driver development for the R200 line ended with the Catalyst 6.11 drivers for Windows XP.

ee also

*ATI Technologies
*Comparison of ATI Graphics Processing Units

References

* [http://www.beyond3d.com/reviews/ati/radeon8500/ "ATi Radeon 8500 64 MB Review (Part 1)"] by Dave Baumann, Beyond3D.Com, March 29 2002, retrieved January 14 2006
* [http://www.beyond3d.com/reviews/ati/radeon8500p2/ "ATi Radeon 8500 64 MB Review (Part 2)"] by Dave Baumann, Beyond3D.Com, April 4 2002, retrieved January 14 2006
* [http://www.xbitlabs.com/articles/video/display/radeon-9100.html "ATI RADEON 9100 Based Graphics Cards Review: Gigabyte and PowerColor Solutions"] by Tim Tscheblockov, X-Bit Labs, February 5 2003, retrieved January 9 2006
* [http://www.anandtech.com/showdoc.aspx?i=1517 "ATI's Radeon 8500 & 7500: A Preview"] by Anand Lal Shimpi, Anandtech, August 14 2001, retrieved January 9 2006
* [http://www.anandtech.com/showdoc.aspx?i=1544 "ATI's Radeon 8500: She's got potential"] by Anand Lal Shimpi, Anandtech, October 17 2001, retrieved January 9 2006
* [http://www.beyond3d.com/misc/chipcomp/?view=chipdetails&id=13&orderby=release_date&order=Order&cname= "ATI R200 Chip Details"] by Beyond3D, retrieved January 9 2006
* [http://www.beyond3d.com/misc/chipcomp/?view=chipdetails&id=16&orderby=release_date&order=Order&cname= "ATI RV250 Chip Details"] by Beyond3D, retrieved January 9 2006
* [http://www.beyond3d.com/misc/chipcomp/?view=chipdetails&id=17&orderby=release_date&order=Order&cname= "ATI RV280 Chip Details"] by Beyond3D, retrieved January 9 2006