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RC4 Code Achieves 319 MB/s On AMD64 Opteron

Posted by timothy on from the even-more-thingy dept.

Marc Bevand writes "This recent paper is about optimizing RC4 for AMD64 processors. A working implementation is provided. Its encryption/decryption throughput reaches 319 MB/s on a single AMD Opteron x44 processor running at 1.8 GHz. This makes it, as of today, the world's fastest RC4 symmetric cipher implementation for general purpose CPUs. As the author of this work, I would like to point out that many CPU-hungry applications have not been optimized for AMD64 yet. In other words: such speedups can be expected in other areas." An anonymous reader adds some figures for the old implementation: "Opteron 244 1.8 GHz (32-bit) 163 MB/s; Opteron 244 1.8 GHz (64-bit) 135 MB/s."

5 of 177 comments (clear)

  1. Optimisation is definately the key by datajack · · Score: 5, Informative

    I was initially disappointed with the performance of my Athlon64. CPU intensive 64bit code often seemed much slower than it's (heavily optimised) 32bit counterpart.

    Every now & then I come across some code optimised for 64bit processors, and it just flies - as more & more stuff gets the treatment, it will be like upgradingin for free :)

    1. Re:Optimisation is definately the key by Savage-Rabbit · · Score: 5, Funny

      it will be like upgradingin for free :)

      Just don't get too excited. One of my coworkers made this same discovery a while back. Now he runs around the office wearing an "I love Opteron" T-Shirt and starts shouting"Intel is history - Power PC is dead!" everytime somebody mentions the words Opteron or AMD in a sentence. Worst of all he attacks anybody who disagrees and tries to bite them. We tried to knock him out with a dart gun after he savaged a visiting IBM sales rep but even heavy duty veterinary tranqulisers don't seem to have any effect.

      :-D

      --
      Only to idiots, are orders laws.
      -- Henning von Tresckow
  2. Re:Somewhat OT, but... by mczak · · Score: 5, Informative
    AFAIK, the VIA's *only* do AES, as they're designed to make good VPN endpoints. This is cos some hefty AES subroutines are built into the hardware (with software drivers doing the rest).
    True. VIA padlock (as they call it) can currently only do AES in hardware (and it can also generate true random numbers). The next VIA chip called C7 (C5J Esther) however should be able to also do SHA-1, SHA-256 and parts of RSA in hardware (I think it should be available first half of 2005). That's of course still a limited set of encryption algorithms, but it's certainly an improvement.
  3. Re:until by RupW · · Score: 5, Informative

    Sorry it's not immediately obvious to me. Who are they?

    AFAICR AMD paid SuSE to do the original work. I think the main developers were Jan Hubicka, the current x86-64 maintainer, and Andreas Jaeger. SuSE have a few more well-known GCC contributors: look at MAINTAINERS.

  4. Re:Does this change anything for rc5? by RupW · · Score: 5, Interesting

    Will the optimized AMD64 rc4 code provide any boost to those crunching rc5 on an AMD64?

    No, they're entirely different. For a start, RC4 is a stream cipher whereas RC5 is a block cipher. They just share the same inventor, hence the names.

    AFAICR, the RC5 effort uses the register width to try and crack many keys in one go anyway - a different approach to this, which is using the register width to generate more of a single stream in one go.