Hi Ramiro, these for me:
7900GT (the wr card)
7950GT (the wr card)
8500gt 1gb (wr card)
x1950xtx512mb
x1950xt 256mb
1900xtx 512mb
7900gs (samsung) very rare (WR card)
40MHz I think. Didn't tried any bios or timing adjustment.
I had problem at the beginning, at gt2 and gt3 got at last seconds low fps than expected. At gt1 and gt4 had full speed.