Blizzard PPC card operate best from a single OSC,so one of my cards has a single 75Mhz OSC this is my third modifyed card.
68060 can be clocked higher around 80Mhz but the Bvision will not work under OS3.x at this speed,but works fine under OS4.0. so you will have a 40Mhz PCI bus speed under OS4.0.
my fastest card looks as if its going to get faster than 83Mhz bus (334Mhz),and FFTdemo times should inprove. also note 40ns or faster dram chips are needed to overclock at or above 75Mhz with 256Mb max ram in mind.
another important factor about my ram module is track layout/length of the track plays a critical roll and makes a difference between a Blizzard card booting at 80Mhz+. so even if you have the right dram chips iv found it does not always work due-to track layout/length.
FFT Demo test
Speed test for FFT + iFFT: (float)
time needed 15333ms for 413696 samples, => .305904299020767x speed @44100Hz/stereo
Speed test for FFT + iFFT: (integer)
time needed 12874ms for 413696 samples, => .364333599805831x speed @44100Hz/stereo
Speed test for FFT + iFFT: (integer handoptimized 68K ASM)
time needed 10394ms for 413696 samples, => .451263308525085x speed @44100Hz/stereo