LOSTCIRCUITS

Summary

With the RADEON 9800 family, ATI has released an evolutionary step towards higher performance based on a modified R300 core renamed as R350 with the main improvement of featuring the additional F-Buffer. Otherwise, there are some cosmetic changes in the card layout, that is, an improved fan, a different power connector and slightly changed VRM. Under the hood, we still have the same 150 nm process.

So where are the differences in performance? Does the card overclock as well as e.g. the Tyan Tachyon 9700 did? We had no problems in 3DMark2001SE to push way beyond the 20,000 points score but what else is new?

Somehow I like these gargoyles

Even in the best of all scenarios for nVidia's launch of the nV30, that is, with a tape-out in June instead of September, ATI would have had a few months of undisputed leadership, since the R300 was launched in July 2002. That is, turning data into silicon, that is, generating a photo-mask set based on the actual design data and thence growing silicon on the wafers requires several weeks. If corrections become necessary, weeks can easily turn into months. Alas, the problems may have occurred much earlier, that is, on the level of the actual design.

Whoever expects some finger pointing here, rest assured, it won't happen. Finishing up a design is an incredibly complex undertaking with a huge amount of manual design first which is then run through a design rule check followed by several steps including Net List Extraction and finally a Layout vs. Schematics comparison. Every error, including shifting of a single connection can proliferate and will generate multiple errors in the connecting nodes. Some, moreover, will cancel each other out until one is corrected. By the end of the day, a 1 million transistor device can easily take as much as 3 CPU days for a complete verification on a 3 GHz Intel P4 (which is not what is used normally but is a known performance entity).

Doubling the size of the chip will exponentially increase the difficulties and run-times, therefore, weeks of missed deadlines for tape out are often enough the results of a few tiny misses. In all the turmoil about the delayed nV30, it was pretty much overlooked that the scenario described above is the norm, rather than the exception, of course, nobody will admit that, just like everybody has perfectly functioning alpha-0 silicon, at least, if you hear them talking ....

In light of the above it is even more impressive that ATI was able to deliver the R300 on time and it paid off with almost 9 months of rather undisturbed reaping of the high-end market until the first production specimens of the GeForce FX5800 surfaced. DX-9 compliance including 128 bit floating point color precision and a number of other features covered in our RADEON 9700 launch article have become the cornerstones of the high end gaming industry as well. Yet, there were a few small blemishes, lets call them freckles, in the R300 concept.

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