New SQRT real fast !

Kai Schuetz (kais@Yttrium.Informatik.RWTH-Aachen.DE)
Mon, 15 Jan 1996 16:23:48 +0100


Hi all !

Yesterday we tested some new srqt functions. First I tried a quick
hack after the suggested newton-approximation algorithm and it was three
times as fast as the builtin function.

Next we tested the function Linus suggested. The result was really astonishing:
It seems to be thirthy (in numbers: 30) times as fast as the bultin function.

Next we tried to recompile POVray, which's performance on teh ALPHA was
slightly disappointing in comparison to intel-based machines.

And, _WOW_, it's twice as fast on the JENSEN as with the bulting sqrt.
(fish13.pov 320x200 -q9 ~141s usertime on JENSEN with 150MHz 21064)
Now it's approx. twice as fast as my 486DX4-100.

POVray seem to use sqrt _really_ heavily.

BTW.: We used POVray with the upcoming SVGALIB for JENSEN by Stephan Kanthak.

-- 
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|\ai

--
Kai Schuetz
kais@i6.informatik.rwth-aachen.de