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DeltaChrome in the chips—and cards
DeltaChrome is a chip, or more properly, a line of chips like ATI's R3x0 or NVIDIA's NV3x. The primary DeltaChrome chip is an 8-pipe design with one texture unit per pipe. Its little brother is a 4-pipe version of the same thing. S3 plans to introduce the eight-pipe chip first as a mid-range product, with high-end cards to follow. (S3 is designing entire graphics card solutions for its partners, by the way, not just chips.) The mid-range card will be called DeltaChrome S8, and S3 will offer two flavors of this card, the plain-jane version and the "Nitro." Think NVIDIA's Ultra or ATI's PRO, and you've got Nitro nailed.

Similarly, S3's low-end cards will be based on the 4-pipe chip. They'll be called DeltaChrome S4 and S4 Nitro. The S4 line will have the distinction, if nothing big changes between now and then, of being the first value segment product with four DX9-capable pixel pipelines. The S8 should be the only 8-pipe mainstream part, too, now that the Radeon 9500 Pro has been put out to pasture. Eventually, the 8-pipe DeltaChrome should make its way on to higher-end cards dubbed F1 and F1 Pole.


How DeltaChrome models are positioned. Source: S3 Graphics.

Nevertheless, S3 Graphics is humble about its prospects. The company says it's aiming to deliver a well-balanced part with decent 3D gaming and decent everything else, not a pure benchmark-burner. (For what it's worth, S3 told me current A0 silicon, which isn't running at full speed, currently turns in 3DMark scores between NV31 and NV34. I believe that's 3DMark2001, though.)

S3 has two different reference board designs, a six-layer board for higher speed cards, and a four-layer board for the more affordable stuff. The chip clock speed target for the six-layer board is 315MHz, while the target for the mainstream board is 275MHz. If S3 hits anywhere near those targets, the mid-range DeltaChromes should have fill rates roughly comparable, at least in theory, to a Radeon 9500 Pro. As for memory bandwidth, I don't have exact numbers, but the DeltaChrome memory interface is 128 bits wide. For budget parts, the chips can also accommodate a 64-bit-wide path to RAM.

In order to achieve these speeds, DeltaChrome chips will be fabbed at TMSC on a 130nm process. A move to the use of low-K dielectrics could come later without too much extra effort. Also, the DeltaChrome's pixel pipelines have been kept on a strict diet. I don't have precise numbers, but to give you some idea, the transistor count on the S4 chip should be about 75% that of the S8, which seems like a surprisingly small drop-off for a transition from eight pipes to four. S3 is aiming for low heat output so the cards can survive with small heat sinks, and DeltaChrome includes fine-grained power management capabilities for mobile use.


This 6-layer card is intended for high-performance versions of DeltaChrome


The 4-layer version of S3's reference design was in action when I visited