S3 GammaChromeS18 Graphics Processor Preview

S3 Graphics again reminded the market of itself, not only as the graphics chip developer, but also as a graphics card designer. They have just announced their new GammaChrome chip. Let’s see what has changed since the times of DeltaChrome.

by Anton Shilov , Anna Filatova
03/14/2005 | 07:34 AM

Introduction: a Bit of History

S3, the graphics chip maker, which used to be very well-known by almost every PC user, now is a subdivision of VIA Technologies. They have been trying to return to the desktop graphics market for quite a while now: the last attempt was undertaken on January 7, 2003 when they released their new DeltaChrome graphics processor (for more details see our article called The Return of S3: DeltaChrome Graphics Card Review).


This chip announced as a mainstream solution boasted pretty advanced technical specifications. In particular, it featured 8 pixel pipelines and supported extended DirectX 9 specifications. Besides that DeltaChrome was the first VPU featuring the programmable Chromotion engine capable of processing video streams in real time. It was possible to create an engine like that due to the implemented pixel shaders 2.0+ support. Since DeltaChrome also boasted pretty low power consumption and also supported YPbPr (HDTV) signal output format, it turned out an excellent solution for multi-functional multimedia PCs, which could also serve as home entertainment systems.

Unfortunately, graphics adapters based on S3G DeltaChromeS8 didn’t get very popular because of bblate market arrival and the lack of a North American launch. Of course, early drivers as well as the absence of well-established cooperation with large graphics card vendors also played a significant role here.

A few months later S3 Graphics followed up with the DeltaChromeS8 Nitro graphics processor, which differed from its predecessor by slightly higher working frequency. It works at 325MHz compared with the 300MHz of the S3 DeltaChromeS8.  However, the DeltaChromeS8 Nitro faced similar difficulties as the ‘standard’ S8 of market timing and early software.

Having an uphill battle to win the niche in the mainstream graphics market, S3G expanded into the Value segment and announced DeltaChromeS4 Pro graphics solution, which we have also reviewed on our site (for details please see our article called The DeltaChrome S4 Pro: S3 Graphics' Entry-Level Offspring). According to our tests, the graphics card based on this VPU turned out to be a pretty successful product and competed efficiently with GeForce FX 5200 and RADEON 9600 SE, at the same time boasting a number of unique features absent by the competitors’ solutions.

All in all, S3 Graphics’ attempts to win a worthy place in the desktop graphics market appeared to be a slow start. The solutions based on different DeltaChrome graphics processor modifications never actually hit the market in volume, except for Japan.

S3 Graphics’ Latest Attempt: This Time for PCI Express Platform

Right now the PC market is moving from AGP bus to PCI Express. Both graphics giants, ATI Technologies and NVIDIA Corporation have already managed to develop a whole bunch of solutions for this bus: starting from the budget ones, such as RADEON X300 and GeForce 6200, and finishing with the high-performance expensive ones, like RADEON X850 XT Platinum and GeForce 6800 Ultra SLI.

Of course, it is evident that S3 Graphics couldn’t stay uninvolved into this process, so on March 9, 2005 the company finally raised the curtain of mystery over their new offspring, The GammaChromeS18 graphics processor, which was initially scheduled to come into this world in Q3 2004. The newcomer inherited major architectural peculiarities of the DeltaChrome solution, but also acquired a number of new unique technologies, which are worth our special attention. We will discuss them in detail later in this preview, and in the meanwhile I would like to introduce the major technical specifications of the new S3G GammaChrome S18:

As you see, GammaChrome boasts very contemporary features although it belongs to relatively inexpensive mainstream solutions. Its major technical specifications, such as working frequency and number of pipelines correspond to those of ATI RADEON X600 XT. However, unlike the ATI product, the new solution from S3G boasts a number of additional attractive features.

S3 Graphics: New Chip Needs New Push

S3 Graphics changed the interface of their graphics chip and is now getting ready to start shipping five modifications of their new baby: GammaChromeS18 Ultra, GammaChromeS18 Nitro, GammaChromeS18 PRO, GammaChromeS18 VE and GammaChromeS18 ULP (Ultra Low Power, which will need no active cooling).

GammaChrome Model

Chip Working Frequency








To be announced


To be announced

The GammaChrome product family S3G will soon start shipping some of the models above soon.  The company will start shipping these solutions from online computer retailers in the US. As far as the availability of the GammaChrome based solutions in other markets in Asia, Europe and Africa is concerned, we haven’t got any details yet. However, according to company sources, they are sure to follow shortly.

At first, the GammaChromeS18 PRO graphics cards will retail for $139-$149. Other members of the newly born GammaChrome family are to arrive into the market a little bit later.

Judging by the way the business of new graphics cards vendors is developing in this market, both relatively new players here, S3 Graphics as well as XGI Technologies, are experiencing the same problems: they lack well-established cooperation with the larger graphics card makers. Of course, the actual graphics cards are still made by the same manufacturers, however, they don’t feel like selling those under their own brand name still.

GammaChrome Graphics Processor: Closer Look

PCI Express Interface

GammaChrome products employ a native PCI Express support which is fully compliant with the PCI Express 1.0A specification and can use 16, 8 and 1 lane interface configurations. The appropriate mode will be enabled automatically when the GammaChrome S18 based graphics accelerator is installed into any suitable PCI Express slot. In addition, the chip also supports a few power saving technologies, and features the ability to use a part of the system memory as a frame buffer, which has already become a common thing for most inexpensive graphics solutions. This certainly makes it a very economical and price-attractive choice.

I would like to stress that the PCI Express graphics interface of the S3G GammaChrome is implemented in such a way that the mobile versions of this graphics chip will be able to scale the number of lanes on the fly depending on the workload at the given moment, so that it will reduce the overall power consumption of the graphics subsystem. It is really important because only the PCI Express x16 bus already eats up to 2.5W of power. Although this feature is a typical characteristic of the standard, S3 Graphics claims that they have unique implementations of power management from their extensive history working with top OEM notebook customers.

Right now S3G is focusing on the proprietary implementation of their mobile PCI Express interface. However, it will undoubtedly require their partners to give up standardized MXM and AXIOM connectors since these types of sophisticated ‘built-in’ solutions are generally for ‘thin-and-light’ notebooks. Nevertheless, the company claims that there is a number of companies which expressed vital interest in this implementation. Moreover, the S3 Graphics representatives claim that they are already testing the MXM engineering samples of their GammaChromeXM18 solution.

ChroMAT Memory Controller

One of the new technologies introduced in the S3G GammaChrome is ChroMAT. Its working principles are very similar to the algorithms used by ATI HyperMemory and NVIDIA TurboCache, and the main idea behind this technology implies that it allows using system memory for the needs of the graphics adapter.

S3G ChroMAT technology allows GammaChrome graphics processor to address the system memory directly: write data into and read data from the system memory when necessary. Moreover, the size of the system memory assigned for the needs of the graphics adapter can be adjusted dynamically.

We wouldn’t call this technology new or revolutionary, because the first implementation of this idea in fact appeared together with the introduction of the AGP bus in 1997. It was exactly at that time that they first voiced out the concept of virtual extension of the local video frame buffer into system memory. This was achieved though an address translation and mapping technology referenced as GART. However, its flexibility still left much to be desired: the amount of memory assigned for the needs of the local frame buffer was fixed and was set during OS boot-up. The AGP data transfer rates also were a way too low. With the increase of the onboard graphics memory by the add-on graphics accelerators GART technology was little by little pushed into oblivion.

At present however, the idea to use a part of system memory for the video needs is picking back up, because the PCI Express bus boasts not only high data transfer rates, but also offers bi-directional transfer, unlike AGP interface. Such technologies as S3G ChroMAT, ATI HyperMemory and NVIDIA TurboCache allow making value graphics products even more affordable, because they will no longer need a lot of onboard graphics memory.

Just like in case of the two above mentioned graphics market leaders, the ChroMAT technology from S3 Graphics required a few changes in the memory controller, which has now acquired the ability to mask delays, to load the system memory interactively in order to optimize data reading and writing, and other similar technologies.

Vertex and Pixel Processors

Similar to its predecessor, S3G GammaChrome graphics processor supports extended DirectX 9.0 specifications and can process Pixel and Vertex Shaders 2.0+ with 24bit and 32bit precision respectively.

According to S3 Graphics, the same number of vertex and pixel processors (4 of each) guarantees better-balanced gaming performance. However, we wouldn’t take this statement for granted and will be checking it in real gaming applications before making any final conclusions. We are already running all necessary benchmarks and soon will offer you a detailed report of how balanced the gaming performance of the new GammaChrome actually is.

The list of additional new features acquired by the GammaChrome pixel and vertex processors is impressively long:

In the meanwhile S3 Graphics doesn’t reveal a lot of details about the innovations introduced in their GammaChrome S18 and S19 family. However, I suppose that the most serious changes have been made to the data caching system. We do not know exactly yet if the new S18 now have more execution units (although we are pretty much sure that it does), however, S3G claims that they eliminated a number of “issues” they used to have since the times of DeltaChrome. They also claim that they will make a number of additional improvements and optimizations to their upcoming S19 model, which will have 8 pixel pipelines.

The only thing that is evident so far is that the company is using 0.13micron manufacturing technology, which permitted to increase the working frequency of the chip. Higher core clock together with some architectural optimizations (supposedly higher number of ALUs per pipeline) allowed the four-pipeline GammaChrome S18 PRO to compete with ATI RADEON X600 PRO. As we all remember, DeltaChrome S8 with 8 pixel pipelines could hardly retain the parity with RADEON 9600 PRO featuring only 4 pixel pipelines.

Chromotion 2.0

The new S3G graphics processor also acquired a new version of the programmable Chromotion engine, which we have already discussed in detail in our article called The Return of S3: DeltaChrome Graphics Card Review. Chromotion 2.0 is fully compatible with DirectX-VA and can process any video formats: WMV, MPEG-2, MPEG-4/DivX, etc. The list of supported features for Chromotion 2.0 is pretty long:

The last three items are the most interesting ones, I should say, since these are brand new features, which didn’t exist in the old engine version. Let’s take a closer look at them now.

ChromoColor technology allows adjusting brightness, contrast, hue and saturation of the video playback with the help of special pixel shaders instead of using the Overlay Engine. This approach has certain advantages: the settings work for an unlimited number of video streams, while the traditional adjustment is usually limited by the number of overlay engines.

ChromoColor mode is enabled automatically when the S3G drivers detect the corresponding hardware in the system. The settings can be modified in the S3G Color Plus page:

The idea behind PureFlow Technology implies that the color data do not get transformed during video files playback or image display on the TV screen. PureFlow technology allows direct transmission of YUV data to the TV encoder. Without this technology the YUV data needs to be converted to RGB format inside the graphics processor before it is displayed onto a TV screen, even if the device connected to the TV-Out of the graphics card is working in the full-screen mode.

The conversion of YUV to RGB is a complex process involving floating-point calculations, which automatically results into certain errors during rounding operations and this inevitably tells on the quality of the final image. PureFlow technology allows skipping the conversion if the display device is working in the full-screen mode. This approach improves the image quality, because there are no errors resulting from inaccurate conversion procedures that affect the final image.

S3G PureFlow technology works with regular TV-sets as well as with HDTV devices, since YPbPr format is simply another variation of HDTV.

ChromoVision allows borderless video playback full screen on a TV or HDTV while windowed video plays on a fully functional desktop visible on another display device. ChromoVision can be enabled if two display devices are connected to the primary output port. The user can resize the window or move it on the PC monitor without any visible effects displaying on the TV screen or HDTV device. The Chromotion effects will however be displayed on both: PC monitor window as well as the full-screen video.


Besides the traditional TrueColor mode, S3G GammaChrome also supports DeepColor mode, which can display up to a billion colors. This mode works just like the Matrox GigaColor technology: it reduced the width of the alpha-channel to 2 bits thus increasing the precision of R, G and B color channels by 2 bits each. This way, DeepColor is configured as 10:10:10:2, while all traditional video modes use 8:8:8:8 formula. In other words, it uses 30 bits to display the color information against the traditionally used 24 bits.

It is known that most digital cameras and photo scanners produce images with 10bit+ color precision per component. However, since the standard PC video system is limited to 8bit per component, a lot of small details get lost when the image is displayed on the monitor. DeepColor allows avoiding this loss of information, because in this mode the color palette is 64 times larger than in the standard TrueColor mode.

In monochrome display mode DeepColor offers 1024 distinct shades of gray, which is 4 times more precise than what we can get in the standard mode. This feature makes DeepColor technology very efficient for the medical applications, such as X-Ray photographs for instance, where smallest details are all displayed in different shades of gray. S3G DeepColor technology will hardly be efficient for games, however, it undoubtedly has enormous potential in some other fields.

Hi-Def Experience

HDTV encoder built into the GammaChrome chip supports all existing standards including 1080p and has the following features:

Due to this broad functionality in terms of video playback and processing, as well as due to the CCIR656 and I2S interfaces support, S3G GammaChrome turns out an excellent solution for home entertainment systems using Windows XP Media Center Edition operating system.

Preliminary Conclusion

According to the above discussed technical data we can draw a pretty simple conclusion. GammaChrome is a well enhanced DeltaChrome, which can successfully compete with RV370 architecture from ATI Technologies in efficiency as well as performance, according to S3 Graphics. If S3G manages to release into the market their 8-pipeline GammaChromeS19 chip fast enough, then multimedia enthusiasts will undoubtedly get attracted to this product (if S19 turns out a worthy competitor to ATI RADEON X700 PRO type of solutions or better, of course).

The main question we ask today is; will the newcomer become popular or it will share the destiny of DeltaChrome? Well, it is all in the hands of S3 Graphics. If they ship the products to the market fast enough and if they succeed in partnering with some graphics card vendors, then why not? Also, we hope sincerely that the drivers for the new GammaChrome will be free from DeltaChrome’s early problems.

S3 Graphics claims that there is a number of companies interested in the mobile and desktop versions of their new GammaChrome chip. All in all, it is a very good sign, because no presence in the graphics market is the major difficulty such companies as S3 Graphics and XGI Technologies are facing right now. When there is no actual product in the market, the product developer gets caught in a vicious circle: the game developers do not want to test their software on a product which is not in the market, and the graphics card makers do not want to sell products, which haven’t been tested for compatibility in contemporary games.

Moreover, the company claims that they worked real hard on improving the drivers and compatibility of the new GammaChrome in the games. Of course, this will be another plus S3G scores, because no multimedia entertainment system can live without 3D games.

Right now we are finishing the tests of the new S3 GammaChrome graphics card in our lab. So hopefully very soon we will be able to estimate the performance of the newcomer in real games. However, right now we already feel confident to say that this is a very interesting chip with a number of truly unique features, which may make the products based on it a very good choice for your needs.