is it a PCI card?
it means, that the PCI clock is 33Mhz and Data Through Put of 133MB/s
where the AGP 4X (your board must have at least) is clocked at 266Mhz and peak throughput of 1GB/s data.
see the difference your self.
I think it can be installed in both AGP and PCI slots (a little confution on ATi's own site, as they mentioned (OR) )
see as if it can be installed into AGP, (if the PCI version isnt seperately made). else get rid of it and get the AGP version.
are you having the tiny PC? as small form factors like Dell Dimension 4700C series comes in PCI slots only. (I have a similar thin IBM Netvista at home, with no AGP slot)