math.BigInteger Performance

Discussion in 'Java' started by rmcnutt, Feb 3, 2004.

  1. rmcnutt

    rmcnutt Guest

    Does anyone know if the AMD Athlon 64 offers a significant performance
    increase for the BigInteger class? I'm currently using an Athlon XP
    2K which is faster than a comparable Intel for Integer and Floating
    Point. I'm wondering if the the 64 is worth the money.
    rmcnutt, Feb 3, 2004
    #1
    1. Advertising

  2. rmcnutt wrote:

    > Does anyone know if the AMD Athlon 64 offers a significant performance
    > increase for the BigInteger class? I'm currently using an Athlon XP
    > 2K which is faster than a comparable Intel for Integer and Floating
    > Point. I'm wondering if the the 64 is worth the money.


    I'm sorry, I thought you wrote "BigInteger" and "performance" in the
    same sentence. Oh, wait, you did! How bizarre.

    I don't actually know whether you would see an improvement with an
    Athlon 64, but my bet would be no -- until and unless you get a 64-bit
    JVM and a 64-bit OS to run it on. Perhaps you might get an overall
    boost from the general 32-bit mode performance of the '64, but for that
    you might also consider an Athlon XP 3K, or whatever they're up to now.
    You might even be able to use that in your current computer.


    John Bollinger
    John C. Bollinger, Feb 3, 2004
    #2
    1. Advertising

  3. John C. Bollinger wrote:
    > rmcnutt wrote:
    >
    >> Does anyone know if the AMD Athlon 64 offers a significant performance
    >> increase for the BigInteger class? I'm currently using an Athlon XP
    >> 2K which is faster than a comparable Intel for Integer and Floating
    >> Point. I'm wondering if the the 64 is worth the money.

    >
    >
    > I'm sorry, I thought you wrote "BigInteger" and "performance" in the
    > same sentence. Oh, wait, you did! How bizarre.
    >
    > I don't actually know whether you would see an improvement with an
    > Athlon 64, but my bet would be no -- until and unless you get a 64-bit
    > JVM and a 64-bit OS to run it on. Perhaps you might get an overall
    > boost from the general 32-bit mode performance of the '64, but for that
    > you might also consider an Athlon XP 3K, or whatever they're up to now.
    > You might even be able to use that in your current computer.
    >


    Are you aware that there IS a 64 bit JVM and 64 bit OS available NOW for
    the AMD64? (Blackdown and Linux respectively.)

    Mark Thornton
    Mark Thornton, Feb 3, 2004
    #3
  4. Mark Thornton wrote:

    > John C. Bollinger wrote:
    >> I don't actually know whether you would see an improvement with an
    >> Athlon 64, but my bet would be no -- until and unless you get a 64-bit
    >> JVM and a 64-bit OS to run it on. Perhaps you might get an overall
    >> boost from the general 32-bit mode performance of the '64, but for
    >> that you might also consider an Athlon XP 3K, or whatever they're up
    >> to now. You might even be able to use that in your current computer.
    >>

    >
    > Are you aware that there IS a 64 bit JVM and 64 bit OS available NOW for
    > the AMD64? (Blackdown and Linux respectively.)


    I was aware that 64-bit Linux was available for AMD64. I was not aware
    that Blackdown had a 64-bit optimized version of their JVM for that
    platform. That's pretty cool.

    It remains an open question whether that combination would be a
    satisfactory alternative for the OP, but in any event I am curious as to
    just what kind of performance differences one would see with it. Does
    Blackdown make any claims about it? Can anyone out there comment?


    John Bollinger
    John C. Bollinger, Feb 4, 2004
    #4
  5. John C. Bollinger <> writes:

    > Mark Thornton wrote:
    >
    >> John C. Bollinger wrote:
    >>> I don't actually know whether you would see an improvement with an
    >>> Athlon 64, but my bet would be no -- until and unless you get a
    >>> 64-bit JVM and a 64-bit OS to run it on. Perhaps you might get an
    >>> overall boost from the general 32-bit mode performance of the '64,
    >>> but for that you might also consider an Athlon XP 3K, or whatever
    >>> they're up to now. You might even be able to use that in your
    >>> current computer.
    >>>

    >> Are you aware that there IS a 64 bit JVM and 64 bit OS available
    >> NOW for the AMD64? (Blackdown and Linux respectively.)

    >
    > I was aware that 64-bit Linux was available for AMD64. I was not
    > aware that Blackdown had a 64-bit optimized version of their JVM for
    > that platform. That's pretty cool.
    >
    > It remains an open question whether that combination would be a
    > satisfactory alternative for the OP,


    It depends on what his code does. I've done a simple test with
    BigInteger::multiply(), the 64-bit VM was about 25% faster. But I
    wouldn't claim all BigInteger code will run 25% faster based on that
    single test.

    > but in any event I am curious as to just what kind of performance
    > differences one would see with it. Does Blackdown make any claims
    > about it? Can anyone out there comment?


    It's noticeably faster than the IA32 VM running on the same machine in
    _almost_ all benchmarks. The main reason is that you have more
    registers in 64-bit mode (16 vs 8 GPRs, 16 vs 8 SSE registers).
    Code using Java longs also benefits a lot (ie. more than other code)
    from having 64-bit wide registers.
    (These results are pretty much consistent with those of GCC benchmarks
    comparing 32-bit and 64-bit code on AMD64.)

    Note that the AMD64 VM is HotSpot-Server only. So if you do
    benchmarks against the 32-bit VM, make sure you compare it to the IA32
    Server VM (java -server ...).


    Juergen

    --
    Juergen Kreileder, Blackdown Java-Linux Team
    http://www.blackdown.org/java-linux/java2-status/
    Juergen Kreileder, Feb 4, 2004
    #5
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. nick
    Replies:
    0
    Views:
    898
  2. nick
    Replies:
    1
    Views:
    31,768
    Eric Sosman
    Oct 26, 2004
  3. j1mb0jay
    Replies:
    25
    Views:
    23,614
    Arne Vajhøj
    May 25, 2008
  4. Stefan Ram
    Replies:
    0
    Views:
    393
    Stefan Ram
    Jul 9, 2008
  5. VK
    Replies:
    15
    Views:
    1,161
    Dr J R Stockton
    May 2, 2010
Loading...

Share This Page