MRT allows for rendering to multiple texture targets in the pixel shader, but I'm not sure how many targets that is.
I'm currently using 3 render targets but I may need as much as 5 (though probably just 4). I think the Radeon 9500s are pretty much entry level ps/vs 2.0 cards but I'm really not sure how many render targets it actually supports besides the fact it supports them?
Thanks for any help!
Non definitive answer:
ATI R600 and above have up to 8 (Earlier cards, 9x00 and up also have MRT, but I'm not sure how many)
NVidia 6x00 and above have up to 4 (I thought G80+ was supposed to do 8, but mine says only 4)
The number for your current card is in the DX Caps member "NumSimultaneousRTs"
I's say 4 is probably the safe bet. If you need more you may want to consider rejigging/encoding the data till it fits in 4, since bandwidth is still always a worry :-)