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 How
fast is Fractal Forge?
Notes by Uberto Barbini.
I wrote this when I released True Mandel 1.6:
It's very difficult to understand the speed of a fractal program. I evaluated a lot of programs both for Windows and for Mac. Most are very fast because they use very poor precision algorithms. Besides they don't always show all the parameters you need to compare the drawings among them.
Another problem is the kind of optimization; I know three types. First there are "adjacent colors based" algorithms. They can greatly decrease execution time when large spots of a single color characterize the images. True Mandel uses two algorithms of this kind. You can choose them from optimization combobox. Normal is a good choice (I think it's the same as FractInt), Turbo is faster but it lacks in precision, especially where nearly round areas touch.
The second kind is based on the behavior of the iteration coordinates. It's worth it for a very high iteration value only (greater than 1000). I didn't include it because it doesn't work in most cases, and is slow in others.
The third type is based on pre-calculated zones. It consists in checking if every point lies in an area mathematically defined as belonging to Mandelbrot Set. Another similar algorithm is based on the symmetry of Real axis of the Mandelbrot Set. I didn't include any of them because they speed up only low magnified images or special zones.
You can also improve calculation code for a specific processor (I worked a lot on Pentium).
But every month someone announces a new wonderful fractal algorithm...
Fractal Witchcraft uses a very interesting new algorithm (synchronous orbits) that in some cases improve speed from 10 to 100 times... I'll try to implement it in future versions.
However I'm looking for a parallel multi-tasking algorithm to use all Windows NT features. Can you imagine fractal generation on a four 200 MHz Pentium Pro system? (The fastest PC you that can buy at the moment).
My computer is a Pentium 100Mhz with 16 Mb ram chipset Triton, 256k writeback cache, Advance Logic 2302 video card with a 1 Mb Dram PCI, hard disk WD Caviar 850Mb.
I tested WinFract 18.21 FractInt 19.2 and Fractal Witchcraft (rumored as the fastest fractal program) with these values:
Dimension: 640 x 480 pixel
Ora 53" con Bounds nota + dell'incremento matematico
Min - max X (real part): -1.16235 -1.16227
Min - max Y (imaginary): 0.22726 0.22732
Iterations: 10000
WinFract 18.21 (floating point and 16bit values on, other parameters as default) 7' 29".
FractInt 19.2 (floating point on, other parameters as default) 6' 22".
Fractal Witchcraft (edge on, warp on) 5' 01".
Fractal Witchcraft (edge on, warp off) 8' 08".
Fractal Witchcraft (edge off, warp off) 10' 28" (Warp on decrease precision).
True Mandel 1.5 (priority High, optimization Normal) 5' 00".
True Mandel 1.5 (priority Very high, optimization Turbo) 3' 54".
True Mandel 1.6 (priority High, optimization Normal) 4' 06".
True Mandel 1.6 (priority Very high, optimizationTurbo) 3' 14".
Dimension: 640 x 480 pixel
Min - max X (real part): -0.5510313972380302 -0.55103139721913384
Min - max Y (imaginary): 0.6271333416120786 0.6271333415748123
Iterations: 12000
FractInt 19.2 (floating point on, other parameters as default) 6' 10".
Fractal Witchcraft (edge on, warp on) 1' 07".
Fractal Witchcraft (edge on, warp off) 1' 21".
True Mandel 1.5 (priority High, optimization None) 5' 16".
True Mandel 1.6 (priority High, optimization None) 4' 31".
True Mandel is the fastest now! It's due to 32 bits code and Pentium optimization fpu routines.
But in some cases Fractal Witchcraft seems fly...
Note that Fractal Witchcraft edge detection method doesn't reduce precision.
Note also that 24 bit graphics is slower than 8 bit...
Now (December 1999) the situation is very similar. Fractal Witchcraft has been abandoned and no other program uses its algorithm. Anyway, it seems to be better in only a few cases. The best fractal program right now seems to be UltraFractal (www.ultrafractal.com), but I still think Fractal Forge is easier to use.
I didn't do very detailed tests, but Fractal Forge appears to be a little faster than UltraFractal (on similar conditions), and significantly faster than any other fractal program. Anyway, UltraFractal is by far more powerful and customizable than Fractal Forge.
And Fractal Forge is freeware ;-)
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