Not quite Crashman, the 9800 (R350) chip is heavily based on the 9700 (R300) chip, but there are slight optimizations to the shader units that removed some limitations, from what I understand.
Still, it doesn't make much of a difference in performance at all.
And yes, video card memory is DDR... double data rate, which means some companies will list it at it's "true" rate, and some will list it at it's "effective" doubled rate, but it's the same thing.
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Radeon 9500 (modded to PRO w/8 pixel pipelines)
AMD AthlonXP 2000+
3dMark03: 3529