The 4850 uses lower bandwidth due to 256 bit-wide + GDDR3 and frequency, so that should imply on a lower performance than 4870. The 4850 probably could not have shaders being disabled due to performance issues and competition. The best bet was to keep its design and performance being controlled by its bandwidth and frequency. A 4850 overclocked with a GDDR5 would be interesting.
Metroid.





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