Well, of course increasing the core frequency alone is not enough for a successful product and the developer went further and equipped the Chrome S20 series with a new memory controller that supports all existing types of graphical DRAM, from DDR to GDDR3. The size of the caches and the number of the chip registers has also been increased. In other words, the Chrome S20 can execute longer instructions. We are talking about the internal instructions the GPU actually executes because, just like in ATI’s and NVIDIA’s solutions, the GPU is supplied the instructions by the driver’s software compiler which performs on-the-fly translation of the original shader code into the native code of the graphics architecture the compiler is optimized for. Quoting S3 Graphics representatives, the efficiency of the shader compiler in the new driver that supports the Chrome S20 has been increased, but we are yet to discover how efficient it really is.
Coupled with 8 pixel and 4 vertex processors and GDDR3 memory clocked at 700 (1400) MHz, this should help the new graphics card be competitive in its category. Since the new product is architecturally a direct descendant of the DeltaChrome and GammaChrome, it can only work with Shader Model 2.0. More exactly, the chip and its predecessors support the extended specification Shader Model 2.0+ (do not confuse it with Shader Model 2.0b), but this is of no practical use to us since these extensions are totally ignored by game developers.
Among other innovations we want to single out the support of S3 MultiChrome technology, similar to ATI’s CrossFire and NVIDIA’s SLI. S3 Graphics being a subdivision of VIA Technologies, MultiChrome-compatible graphics cards are expected to be mostly used on the recently announced VIA K8T900 platform which supports the PCI Express x8 + x8 formula. S3 claims that there are no obstacles to joining two S3 Chrome S27 cards into one graphics subsystem on other platforms, but we can’t yet check this out because we have only one sample of the card.
The S20 series also features the updated video engine Chromotion which is already version 3.0. It supports all HDTV standards, including 1080i/p, and offers some thrilling features like scaling a standard 4:3 image to fill a widescreen 16:9 display. The video engine supports hardware WMV9 decoding, including the WMV HD standard, but the H.264 codec is not supported, and RADEON X1000 remains the only graphical architecture to offer hardware decoding of the new HDTV format.
Another new technology, AcceleRAM, is available only in the Chrome S25 and is similar to NVIDIA’s TurboCache and ATI’s HyperMemory. Easy to guess, its point is in using some of the computer’s system memory to store graphical data. Of course, there are no hardware restrictions against using AcceleRAM with the Chrome S27 which is architecturally the same as the Chrome S25, but the higher-performance Chrome S27 comes already equipped with enough of onboard memory, either 128 or 256MB. We won’t discuss AcceleRAM for long since this review is about the S3 Chrome S27. Suffice it to say that this technology was made possible by the new memory controller which makes its debut in this new GPU series.
We are now going to verify that S3 Graphics has got rid of the deficiencies of its earlier products and to estimate the performance of the Chrome S27 in today’s applications. Let’s have a closer look at the new graphics card.