The 9800se's are clocked much higher than the 9500s, so they have a performance advantage.
Either one can be softmodded to enable the dormant 4 pixel pipelines, with about a 50% failure rate.
The 9500 can be modded to a 9500 PRO or 9700 depending on the memory configuration.
The 9800se can be modded to a 9500 PRO equivalent or a 9800, depending on the memory configuration.
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Radeon 9500 (hardmodded to PRO, o/c to 322/322)
AMD AthlonXP 2400+ (o/c to 2600+ with 143 fsb)
3dMark03: 4055