The refresh rate was set to 1.
I have just done everything that LaserBack said at 640*480 reslution and with Speedometer 4.02 i still have 8 bits graphic results equal to 0.174 Quadra 605 with CardTrickEVD and only 0.125 with Picasso96 driver.
It's a bit better than my previous results in 800*600.
Maybe your system is using motherboard ram (very slow) and that is slowing it down?