Basicly to even have the chance of modding a Rad9500 (non-PRO) to a 9700 is if your card has 128MB AND uses the old Rad9700 PCB (they now use a seperate dedicated PCB like the 9500PRO). You then have about a 25% chance of successfully enabling all 8 pipes which is all that seperates this from a true Rad9700 as the 9700PCB with 128MB enables 256bit RAM and obviously the clocks are the same for 9500, 9500PRO and 9700. HOWEVER there's a big chance that EVEN with a 9500 with 128MB on 9700PCB that you'll be left with only 4 pipes, and the perf hit of having only 4 pipes is VERY BIG! At stock speeds the Rad9500 is SLOWER than a GF4TI4200 and unless you enable full AA & AF (GF4TI aren't designed to run with this) the 9500 stays formly behind, considering how little a Rad9500PRO costs it makes sense not to trust to luck ESP since all 9500's now reportedly use their own PCB.
A Rad9500PRO is about GF4TI4400 speeds but obviously much faster with full AA &AF, even with a GF4TI4600 using medium AA & AF the 9500PRO is still faster with FULL AA & AF. JFYI a Rad9500 128MB with 256bit RAM modded & o/c'ed to 400/310 (9700PRO is 325/310) BUT still with only 4 pipes is significantly SLOWER than the lower clocked Rad9700PRO, like 40%. My advice would be NOT to chance to luck with a 9500_128MB but to grab a Rad9500PRO or 9700 and o/c them. The 9500PRO can hit 9700 speeds once o/c'ed and the 9700 often hits 9700PRO speeds when o/c'ed! If you want good perf without risks on a budget look no further than a GF4TI4200 or a 4800SE if the price is right.