Apr 16 2006

Intel Integrated Performance Primitives Bewilderment

Published by at 1:26 pm under Technology   

I’ve been evaluating Intel’s Integrated Performance Primitives, a set of libraries for low-level signal processing and image manipulation. These appear to be very well engineered at the lowest levels, but the packaging is a mess, as I’ll describe below. The point of these libraries is that they use the various enhanced CPU instruction sets (MMX, SSE, SSE2, SSE3, are there more?) of the various Intel processors. Such enhancement are very useful if you are processing a lot of images in a hurry… such as in a video stream.

Big gripe: nearly all of the CPU enhancements that these libraries use, are also available on AMD hardware; but being Intel libraries, these don’t auto-detect and use these things on AMD CPUs. Therefore an off-the-shelf, simple benchmark will show AMD radically slower. Apparently with the right tweaks, the AMD stuff can be used well also, and works fine. Now I can see why Intel would do this, but it has the side effect of making them look scared. Looking scared is not good marketing. I believe it would have been better for them to support AMD seamlessly, and let the benchmarks show that the Intel stuff is a bit faster… if indeed that is what they show.

Now for the bewildering deployment model: These libraries arrive as a large pile of DLLs, with most of them in several flavors, once for each processor family.  But rather than putting the “which logic to load” code in a DLL, that code is supplied only in a .lib file – so it’s quite amenable to use from C code, and much less so from non-C code.

Next bewilderment: To the “rest of us”, getting a machine with a 64-bit processor (Intel EM64T, AMD64) is no big deal, it’s just another CPU family.  But to Intel the IPP developers, it’s a separate product version, with a separate way to invoke it, and no clear example code to show how to auto-load the right libraries (and of the 32-bit, any of the 64-bit) as needed depending on CPU type.  Apparently it did not occur to them that this could have been seamless.

Next bewilderment: Until a few years ago, the “Intel JPEG Library” was a popular, free, and very fast JPEG compression / decompression library.  It’s not free anymore, it is now part of IPP.  I have no objection to that, IPP is a very good value at $200 per developer.  The bewilderment is that rather than supply the working “Intel JPEG Library” as part of IPP, they instead supply it only as example code.  The deveoper than compiles the sample code to get an IGL DLL that runs on top of IPP, with all of the deployment issues mentioned above.  Again, this could have been trivial, and would meet a lot of developers’ needs, but is instead a mess of accidental complexity.  IPP provides a large number of low-level functions useful to write a JPEG compressor / decompression, but a lot of us (myself and this fellow, for example) don’t want to learn the inner working of JPEG; it seems as though IPP could benefit greatly from some higher level API calls.

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