AMD-64 systems and Java performance

Discussion in 'Java' started by Dean Schulze, Sep 7, 2004.

  1. Dean Schulze

    Dean Schulze Guest

    Does anyone have any comparisons or benchmarks for compiling and running
    Java programs on AMD-64 systems compared to 32-bit Intel systems?

    I'm considering buying an AMD-64 notebook which will run Windows XP Pro.
    I believe the 64-bit support for XP was just released (or release is
    imminent). I haven't seen a 64-bit JDK for the AMD-64 based systems
    yet, though so initially I'll be using the 32-bit JDK.

    I'm wondering if the 32-bit based javac and java run as a function of
    clock-speed only or if they can take advantage of some features of the
    64-bit hardware. Since the AMD-64's CPU clock-speed is slower than
    comparable Intel CPUs I worry that the AMD-64 based systems may actually
    be slower for compiling and running Java programs than comparable 32-bit
    Intel hardware.

    Thanks.
     
    Dean Schulze, Sep 7, 2004
    #1
    1. Advertising

  2. Dean Schulze

    Frank Guest

    Dean Schulze wrote:
    > Does anyone have any comparisons or benchmarks for compiling and running
    > Java programs on AMD-64 systems compared to 32-bit Intel systems?
    >
    > I'm considering buying an AMD-64 notebook which will run Windows XP Pro.
    > I believe the 64-bit support for XP was just released (or release is
    > imminent).


    Don't know about that.. There's a beta out, but it's ridden with bugs
    and driver support is abysmal.

    > I haven't seen a 64-bit JDK for the AMD-64 based systems
    > yet, though so initially I'll be using the 32-bit JDK.


    There's AMD-64 support in Java 1.5, check out RC1. I have no idea how it
    performs, though, don't have the balls (or time) to dig up a 64-bit
    linux platform and check it out.

    > I'm wondering if the 32-bit based javac and java run as a function of
    > clock-speed only or if they can take advantage of some features of the
    > 64-bit hardware. Since the AMD-64's CPU clock-speed is slower than
    > comparable Intel CPUs I worry that the AMD-64 based systems may actually
    > be slower for compiling and running Java programs than comparable 32-bit
    > Intel hardware.


    The main advantage of 64-bit CPUs on any sane platform is getting access
    to more than 2-4GB RAM, which doesn't help much atm except for on pretty
    large servers.

    X86 is a shitty piece of architecture, though, and the AMD64 does a
    little mending to the worst x86 deficiency, namely doubling the number
    of general purpose registers which was merely 8 before, while anything
    else has had at least 32 for decades.

    It also doubles the amount of simd registers, effectively deprecating
    the silly stack based fpu.

    I've heard the changes will yield anything from 0% to 50% performance
    improvement compared to the same code compiled for 32-bit mode, but
    never saw any actual benchmarks.. 20-30% seems a reasonable estimate IMO.

    There are a few other neglible improvements as well, but these are
    likely to be eaten up by for instance the 10% increased code size of
    64-bit apps, which means you'll have more cache misses and so on.

    I wouldn't be concerned about clock speeds. Current AMD CPUs outperform
    intel's offerings, even at significantly lower frequencies.

    -Frank
     
    Frank, Sep 7, 2004
    #2
    1. Advertising

  3. Dean Schulze

    Dean Schulze Guest

    The only thing I've been able to find is this:

    http://www.manageability.org/blog/stuff/java-64-bit-amd-opteron

    Looks like the extra registers help even with a 32-bit JVM. There also
    seems to be quite a bit of potential once a 64-bit JDK is available with
    good 64-bit support in the OS.



    Frank wrote:
    > Dean Schulze wrote:
    >
    >> Does anyone have any comparisons or benchmarks for compiling and
    >> running Java programs on AMD-64 systems compared to 32-bit Intel systems?
    >>
    >> I'm considering buying an AMD-64 notebook which will run Windows XP
    >> Pro. I believe the 64-bit support for XP was just released (or
    >> release is imminent).

    >
    >
    > Don't know about that.. There's a beta out, but it's ridden with bugs
    > and driver support is abysmal.
    >
    >> I haven't seen a 64-bit JDK for the AMD-64 based systems yet, though
    >> so initially I'll be using the 32-bit JDK.

    >
    >
    > There's AMD-64 support in Java 1.5, check out RC1. I have no idea how it
    > performs, though, don't have the balls (or time) to dig up a 64-bit
    > linux platform and check it out.
    >
    >> I'm wondering if the 32-bit based javac and java run as a function of
    >> clock-speed only or if they can take advantage of some features of the
    >> 64-bit hardware. Since the AMD-64's CPU clock-speed is slower than
    >> comparable Intel CPUs I worry that the AMD-64 based systems may
    >> actually be slower for compiling and running Java programs than
    >> comparable 32-bit Intel hardware.

    >
    >
    > The main advantage of 64-bit CPUs on any sane platform is getting access
    > to more than 2-4GB RAM, which doesn't help much atm except for on pretty
    > large servers.
    >
    > X86 is a shitty piece of architecture, though, and the AMD64 does a
    > little mending to the worst x86 deficiency, namely doubling the number
    > of general purpose registers which was merely 8 before, while anything
    > else has had at least 32 for decades.
    >
    > It also doubles the amount of simd registers, effectively deprecating
    > the silly stack based fpu.
    >
    > I've heard the changes will yield anything from 0% to 50% performance
    > improvement compared to the same code compiled for 32-bit mode, but
    > never saw any actual benchmarks.. 20-30% seems a reasonable estimate IMO.
    >
    > There are a few other neglible improvements as well, but these are
    > likely to be eaten up by for instance the 10% increased code size of
    > 64-bit apps, which means you'll have more cache misses and so on.
    >
    > I wouldn't be concerned about clock speeds. Current AMD CPUs outperform
    > intel's offerings, even at significantly lower frequencies.
    >
    > -Frank
     
    Dean Schulze, Sep 9, 2004
    #3
  4. Dean Schulze

    Frank Guest

    Dean Schulze wrote:

    >
    > The only thing I've been able to find is this:
    >
    > http://www.manageability.org/blog/stuff/java-64-bit-amd-opteron
    >
    > Looks like the extra registers help even with a 32-bit JVM.


    Nah, it doesn't have access to the fancy new stuff unless it's running
    64-bit programs on a 64-bit os.

    It's just performing really well on plain 32-bit code too.

    > There also
    > seems to be quite a bit of potential once a 64-bit JDK is available with
    > good 64-bit support in the OS.


    Yup :) Last comment in your link suggested a 100% speed increase over
    the 32-bit vm (however the 32-bit jvm was running on a 64-bit os, which
    may or may not cause some overhead due to task switching..)

    Done some searching myself, but I'm not finding anything authoritative..

    What I do know is that amd64 offers the best bang for the buck, even
    today, and once you switch to 64-bit there will be a nice speed up.

    -Frank
     
    Frank, Sep 9, 2004
    #4
    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. Larry Doolittle

    Re: OT: EDA tools on AMD-64?

    Larry Doolittle, Aug 1, 2003, in forum: VHDL
    Replies:
    0
    Views:
    966
    Larry Doolittle
    Aug 1, 2003
  2. Chris Roe
    Replies:
    1
    Views:
    351
    Wee Jin Goh
    Jun 11, 2004
  3. Mike
    Replies:
    2
    Views:
    668
  4. Henry Stock

    Silverlight and AMD processors

    Henry Stock, Jul 27, 2010, in forum: ASP .Net
    Replies:
    2
    Views:
    1,126
    Hillbilly
    Aug 18, 2010
  5. Roland Mösl
    Replies:
    0
    Views:
    125
    Roland Mösl
    Dec 9, 2003
Loading...

Share This Page