Introduction

New details emerge on DeltaChrome

It has been well over six months since we first brought you details of S3’s DeltaChrome graphics core. If you recall the original article, DeltaChrome marks S3’s return to desktop graphics, a market it exited approximately three years ago.

DeltaChrome is a DX9 part targeted at the value, mainstream, and performance segments of the 3D market. Unlike ATI and NVIDIA however, S3 plans to service all three segments with roughly the same core architecture. All DeltaChrome chips are built on TSMC’s 0.13-micron manufacturing process (with copper interconnects), with the key differentiating factors being clock speed and the number of pixel pipelines within the chip.

Formula One graphics from S3

For the mainstream and performance segments, S3 relies on an eight-pixel pipeline architecture (with one texture unit per pixel pipeline), with four vertex shaders backing them up, just like ATI’s RADEON 9700/9800 family. Two parts will service the performance market: the F1 and the F1 Pole. S3 is shooting for core clock speeds in the 350MHz-400MHz range for F1 Pole, which would compare favorably to ATI’s RADEON 9700 PRO at 325MHz. Unfortunately the graphics core will only have a 128-bit interface to its memory, which is half the width of ATI and NVIDIA’s equivalent. With the 350-400MHz clock frequency S3 is shooting for F1 Pole’s DDR memory, this equates to up to 12.8GB/sec of peak memory bandwidth, putting the F1 Pole at an extreme disadvantage to its competitors in this category.

DeltaChrome F1 and S8 chips

Just below the F1 Pole is S3’s “F1” DeltaChrome variant. The key distinguishing factor between F1 Pole and F1 is clock speed: S3’s target frequencies for F1 are 50MHz lower on the core and memory clock frequencies than F1 Pole. This is essentially the part S3 briefed us on at the beginning of the year.

From a technology perspective S3 has all their bases covered with DeltaChrome. This is a true DX9 part with full support of floating-point data formats and like ATI’s 9700/9800, its pixel shaders can handle up to 96 bits of precision. The really cool part that really drew lots of attention in our first preview wasn’t the 3D architecture of DeltaChrome but its integrated HDTV encoder. It supports all the major resolutions, 480i, 480p, 720p, 1080i, and 1080p, making it the perfect solution for small form-factor setups.

For cleaning up video, S3’s pixel shaders can be used. They can also be used to add effects to video signals, this is supported by all video formats. ATI has similar technology in its 9700 and 9800 chips.

S3 is quick to point out that the F1 family is not about winning benchmarks in the segment it’s serving, as it obviously lacks the memory subsystem to accomplish this, instead it’s about delivering a part with the lowest cost, and highest value. S3 plans to undercut ATI and NVIDIA in pricing, which we estimate would put the F1 in the $200-$250 range. If S3 goes any higher than that, they run the risk of pricing their chips too closely to ATI and NVIDIA, who have their products already out on the market today.