Articles: Graphics

Bookmark and Share


Table of Contents

Pages: [ 1 | 2 ]

Silicon Integrated Systems is mostly known for its excellent chipsets, but the company also produces graphics chips. Graphics chips from SiS always featured very moderate pricing, and also moderate performance. The company has been rapidly progressing, though. Soon after the launch of SiS315 (see our SiS315 Graphics Chip Review) there appeared a new graphics chip family aka SiS Xabre (see Xabre The Brave: New 3D Hero from SiS).

These chips support DirectX 8.1, multi-display configurations, TV-Out… To cut it short, they have the entire range of features required in an up-to-date graphics card of the mainstream, rather than value level.

The announcement also disclosed the fact that Xabre is the name of a whole family of chips that are based on the same architecture, but have different performance and price:

  • Xabre400 - 250MHz/500MHz (250MHz DDR) frequencies, 128bit DDR SDRAM memory;
  • Xabre200 - 200MHz /333MHz (166MHz DDR) frequencies, 128bit DDR SDRAM memory;
  • Xabre80 - 200MHz /166MHz frequencies; 128bit SDRAM memory.

These are not the all members of the Xabre family. The roadmap we saw at the time of Xabre400/200/80 announcement shows one more, and the fastest, of the Xabres: the Xabre600 that was going to enter the market a bit later:

Xabre600 hit the market in a much more discouraging situation than its predecessors. It's no secret that manufacturers of graphics chips and graphics cards make most money on mainstream and value solutions, which are mass products and are more popular than high-end expensive ones. The leaders in the gaming 3D chips field didn't waste their time and by the time Xabre600 arrived, there had appeared NVIDIA GeForce4MX440-8x and ATI RADEON9000/9000 PRO based cards targeted at the same price range. So, these graphics cards are the immediate rivals to SiS Xabre600.

Now, let's see what the fastest member of the brave Xabre family is like.

Closer Look

First of all, the SiS Xabre600 is made with a finer manufacturing technology than its predecessors. The transition to the 0.13micron tech process allowed to raise the frequencies above the planned 275MHz/300MHz (600MHz DDR). In the Xabre600 announcement (by the way, it's the first graphics chip to be manufactured with this technology) we read that its frequencies would be 300MHz/600Mhz (300MHz DDR). The clear minds of marketing men from SiS even coined a new word: "Duo300" that is supposed to reflect the power, which brings an imminent ruin to all the competitors.

The frequencies of the sample we had at our disposal are even higher: 315MHz/630MHz (315MHz DDR). We can't tell why they turned to be like that. Maybe all off-the-shelf cards based on SiS Xabre600 will have frequencies like that. But it also may be that the frequencies were only raised in samples, so that the Xabre600 could be in an advantageous position in benchmarks and during the comparison with competitors.

The press release dedicated to the launch of the Xabre600 graphics chip mentions some new features that are not present in other members of the family. So, Xabre600 features not only Pixelizer Engine, Frictionless Memory Control (FMC), Jitter Free Anti-Aliasing and MotionFixing Video processor, which are typical of the entire Xabre family, but also some features, which are supported only by Xabre600. Let's dwell upon the innovations:

Vertexlizer Engine

Vertexlizer Engine is a "hardware optimized" technology that can split vertex processing work between the graphics chip and the CPU. This should lead to more effective vertex processing with less workload laid on the graphics chip.

In other words, vertex shaders are still executed by the software. The CPU calculates the transformations parameters, while the T&L unit of Xabre600 performs the actual vertex transformations. By the way, this technology is not a unique feature of the Xabre600. Our tests showed that it could be activated in Xabre400, too. All you need is to install Xminator II, the new driver from SiS that supports this optimization.

Xmart Technology

Xmart Technology is actually a combination of three "smart" technologies that increase Xabre600 efficiency in graphics applications:

  • XmartAGP automatically determines the AGP port working mode and sets the maximum data transfer rate.
    Actually, this is a requirement for any up-to-date graphics card. The AGP 3.0 specs require all these actions as obligatory.
  • XmartVision adjusts brightness and contrast in 3D applications, automatically evaluating the necessity of these adjustments and the level of gamma correction needed.
    This technology can indeed be of help in "dark" games that don't allow adjusting picture brightness and contrast manually.
  • XmartDrive automatically determines the need to switch the card into top-performance mode and, when a 3D application starts up, sets the graphics chip clock-rate to the maximum. In all the other applications the clock-rate is lowered, thus the power consumption and heat dissipation get reduced.

SiS Xabre600 Based Reference Graphics Card

So, let's examine the reference-card based on the SiS Xabre600 graphics chip. The graphics card is equipped with D-Sub, DVI-I and TV-Out connectors. By the current fashion, it's built on a black-lacquered PCB:


As you can see in the snapshot, the design of the Xabre600 based graphics card differs a lot from Xabre400 based ones. The first thing to catch our eye is the memory chips that are now in BGA packages. They are chips from Hynix with 2.8ns access time.

Under the cooler we found a new graphics chip from SiS: the Xabre600. Like Xabre400, it carries a metal shim to transfer heat from the die to the cooler:

The frequencies of the graphics core and graphics memory of the reference-card are 315MHz/630MHz (315MHz DDR) by default.

Although the graphics core frequency is rather high, its heat dissipation is low (the bottom of the card right under the graphics chip is just a bit warm to the touch when the card works). That's why the card features not a very big cooler:

As in Xabre400 based cards, the Xabre600 reference-card has a SiS301 companion chip onboard providing image output onto a secondary display device: a TV-set or a display with either digital or analogous interface:

The most interesting feature of the card is hardware monitoring implemented via a W83L785R chip from Winbond:

This chip keeps track of two temperature values (through thermal diodes), four voltages and also allows measuring and changing the rotation speeds of two fans.

By the way, in the snapshot of the fan installed on the SiS Xabre600 reference-card you can see a third wire, which transfers the signal from the rotation speed sensor.

So, the reference-card features hardware monitoring options, which are only typical of some "exclusive" graphics cards. It's rather nice. There is only one thing left: we should now check how well the software works with these options.

Drivers and Utilities

The Xminator driver set for graphics cards from SiS has grown to version 3.07 with the launch of the Xabre600 and is now called Xminator II. Let's find the differences and see what is good about the new drivers from SiS.

After we had plugged in SiS Xabre600 based card and installed the software from the CD, the Display Properties dialog box showed a new properties page:

This page in Xminator II v.3.07 doesn't differ from the same page in the first Xminator for the Xabre400. As there is nothing new here, let's take just a brief walk through the menu items:

Here you can adjust the color gamma of the output image. You can change the "gamma" level of every of the three color components independently as well as the overall Brightness, saturation (Enhance Color) and color balance (TINT).

This dialog box allows adjusting the overlays color gamma. In the preview window there is a test overlay, which of course didn't get onto the screen-shot: you see a pink box instead.

The Product and File Information page tells you that there is really a SiS Xabre600 based card installed in the system :), shows its revision number, clock-rates, memory type, driver version…:

…and also the version of each file from the SiS' driver set:

TV-Out and multi-display configurations can be set up in the Driver Mode Settings page:

Regrettably, unlike ATI and NVIDIA, SiS still doesn't want to place the most interesting things - the 3D settings of the card - in the Display Properties. There is a special utility for it: 3D Wizard, which you can start by clicking the icon next to the clock:

The drop-up menu lists all the items known since the times of SiS Xabre400 and there is nothing new except the item to run the 3D Wizard. This utility did change in Xminator II and became much more functional.

Let's run through the pages here as well:

The 3D Stereo name speaks for itself: here you can try to enable the stereoscopic mode.

Interesting, on marking the Enable Stereo button, the list of stereo modes available gets limited by one item only: "Shuttle class stereo (Wireless)". Since such glasses didn't come with the graphics card we received, we just couldn't test the Xabre600 in stereo modes.

In this page you can set non-nominal clock-rates for the graphics card. It's pleasant that SiS doesn't hide overclocking options like NVIDIA and ATI do. Of course, it's no great task to overclock cards based on graphics chips from ATI or NVIDIA with the help of third-party utilities, but it's really nice when the manufacturer himself makes overclocking easy with a "native" utility.

The "D3D" page allows configuring Xabre600 for work in Direct3D. The "Performance - Quality" slide-bar has three positions and controls texturing quality. When it's in "Performance" or middle (let's call it "Normal") positions, the TexTurboMode=3 is turned on. It provides highest texturing speed at minimum quality. (More details on turbo-texturing modes by SiS Xabre and the image quality in each of them are available in our SiS Xabre400 Review).

In the TexTurboMode=3 Xabre600 uses a horribly-looking approximation with a fewer texture samples instead of bi-linear filtering. Tri-linear filtering is not performed in this mode at all.

In the "Quality" position, the TexTurboMode=1 is enabled, where both bi-linear and tri-linear filtering are performed all right, but the textures level of detail (LOD) is much lower than the default LOD by the graphics chip from ATI and NVIDIA.

It's characteristic that the TexTurboMode=0 mode is not available at all. In this mode the chip from SiS provides about the same texturing quality as graphics chips from ATI and NVIDIA, but such "honest" and correct texture rendering results in a big performance drop.

This page also features the "Performance - Quality" slide-bar and full-screen anti-aliasing options.

The FSAA by SiS Xabre is implemented as supersampling and, as such, simply kills the card's performance. That's why we didn't test Xabre600 with enabled anti-aliasing.

Well, there are a number of games that don't demand much from the graphics card in terms of performance. So, even the slow anti-aliasing from Xabre can be of some value in such a game.

This page serves to set up the XmartVision mode and activate XmartDrive. XmartVision automatically "raises" the color gamma in games, when it considers the gamma to be too dark to play comfortably. The XmartDrive technology automatically reduces the graphics core and memory frequencies when there are no 3D applications running and the maximum performance is not necessary.

Overall, the 3D Wizard utility from the Xminator II driver set has become much more useful. But it still lacks a lot.

For example, there are no pages dedicated to hardware monitoring. As we have already said, these options are implemented in Xabre600 on the hardware level, but Xminator II seems to know nothing about them. It's a pity.

It is interesting that 3D Wizard has now lost the opportunity to enable "semi-transparent" and "wireframe" modes in 3D applications. Did SiS software guys simply consider these options unnecessary or was it the "gaming community" that protested against this kind of "cheating"?

Pages: [ 1 | 2 ]


Comments currently: 0

Add your Comment