IDL performance and FFTs (was: call external speed) [message #12887] |
Wed, 16 September 1998 00:00  |
roy.hansen
Messages: 8 Registered: September 1998
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Junior Member |
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Hi,
In article <Pine.SO4.4.03.9809141531430.9709-100000@sukak>,
Karl Krieger <kak@ipp.mpg.de> wrote:
>
> It really depends on the application. I wrote a LINKIMAGE wrapper for the
> FFTW package ( http://theory.lcs.mit.edu/~fftw ) and compared the speed to
> IDL's native FFT routine. The speed gain for single precision
> real->complex 2d transforms is about 2.5 on a SUN Ultra/170 and about 2.3
> on a Pentium/133 under WinNT, so it's really worth the effort if you want
> to do FFT of large data sets.
>
We did a small comparison of the FFT performance in IDL 5.1.1
compared with the Matlab 5.2 version for a PII-400 with Win-NT,
and found that Matlab was approx 4 times faster. We also found
that the FFT in IDL 5.1.1 was faster than in IDL 5.1 on an other
PII-400 with Win95.
This raises a few questions:
- Does there exist any optimized versions of IDL for the PII and
PPro with W95 and Win-NT?
- Does anybody know what the performance gain is using an optimized
version compared to the standard version?
- Is the IDL performance operating system dependent for the INTEL
platform?
- What's the main differences of version 5.1.1 and 5.1 ?
- Are there any benchmarks of numerical performance for IDL
compared to other software packages, like Matlab?
- If the FFTW (which is free) outperforms the native FFT in IDL,
why don't RSI use that implementation? Is this a silly question?
- RoyH
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