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Re: Java 7 vs 8 speed issues on Win7?

From Knute Johnson <nospam@rabbitbrush.frazmtn.com>
Newsgroups comp.lang.java.programmer
Subject Re: Java 7 vs 8 speed issues on Win7?
Date 2014-11-05 20:00 -0800
Organization A noiseless patient Spider
Message-ID <m3erpb$qt5$1@dont-email.me> (permalink)
References (1 earlier) <ac6k5ahi1h95romsnq52kus20rvbi3psel@4ax.com> <m3ditj$8bd$1@dont-email.me> <m3dus5$q4d$1@news.albasani.net> <m3ej2t$9ae$1@dont-email.me> <m3emtc$bd2$1@dont-email.me>

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On 11/5/2014 18:37, Eric Sosman wrote:
> On 11/5/2014 8:32 PM, Knute Johnson wrote:
>> On 11/5/2014 11:47, Jan Burse wrote:
>>> A fundamental change in one of the newer JDKs
>>> is a changed semantics for substring(int, int).
>>
>> For better or worse?
>
>      "Yes, probably."
>
>      (Given the amount of data provided, that's really all the
> answer one can offer -- and all that's deserved.  C'mon, Knute:
> No description of the application, no hint about its hot spots,
> no profiling data, not even *one* measurement of any kind at
> all ... How in the world can you expect useful feedback when
> you've not fed forward?)
>

I think we are talking about two different things here.

Unfortunately I can't give any good details because I was working on 
this 250 miles away with VNC.  The customer had a failed computer and we 
had to get it running without any delays.

It is not code that was stretching the previous machine with a single 
processor running XP and Java 6 but when we configured a new computer 
with a multi-core processor, Win7 and Java 7 the code barely ran.  It 
was so slow that it was no longer usable.  Put in Java 8 and it is back 
to its old self, tuning along just fine.  I haven't been able to 
duplicate it in my shop and we can't stop the customer's computers to 
play with them.

As to Jan's comments, there isn't a single call to String.substring() in 
the code anywhere and it runs fine with Java 8, so I don't think that is 
the cause.  But I am still curious about what the "changed semantics" 
are and how they might impact performance.

Thanks,

knute...

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Thread

Java 7 vs 8 speed issues on Win7? Knute Johnson <eternal@knutejohnson.com> - 2014-10-22 10:18 -0700
  Re: Java 7 vs 8 speed issues on Win7? Silvio <silvio@internet.com> - 2014-10-24 11:10 +0200
  Re: Java 7 vs 8 speed issues on Win7? Roedy Green <see_website@mindprod.com.invalid> - 2014-11-05 04:36 -0800
    Re: Java 7 vs 8 speed issues on Win7? Knute Johnson <nospam@rabbitbrush.frazmtn.com> - 2014-11-05 08:23 -0800
      Re: Java 7 vs 8 speed issues on Win7? Jan Burse <janburse@fastmail.fm> - 2014-11-05 20:47 +0100
        Re: Java 7 vs 8 speed issues on Win7? Knute Johnson <nospam@rabbitbrush.frazmtn.com> - 2014-11-05 17:32 -0800
          Re: Java 7 vs 8 speed issues on Win7? Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-11-05 21:37 -0500
            Re: Java 7 vs 8 speed issues on Win7? Knute Johnson <nospam@rabbitbrush.frazmtn.com> - 2014-11-05 20:00 -0800
              Re: Java 7 vs 8 speed issues on Win7? Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-11-05 23:32 -0500
                Re: Java 7 vs 8 speed issues on Win7? Robert Klemme <shortcutter@googlemail.com> - 2014-11-06 08:48 +0100
                Re: Java 7 vs 8 speed issues on Win7? Jan Burse <janburse@fastmail.fm> - 2014-11-06 15:09 +0100
                Re: Java 7 vs 8 speed issues on Win7? Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-11-06 09:50 -0500
                Re: Java 7 vs 8 speed issues on Win7? Jan Burse <janburse@fastmail.fm> - 2014-11-06 18:21 +0100
                Re: Java 7 vs 8 speed issues on Win7? Jan Burse <janburse@fastmail.fm> - 2014-11-06 18:34 +0100
                Re: Java 7 vs 8 speed issues on Win7? Jan Burse <janburse@fastmail.fm> - 2014-11-06 23:03 +0100
                Re: Java 7 vs 8 speed issues on Win7? Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-11-06 17:21 -0500
                Re: Java 7 vs 8 speed issues on Win7? Jan Burse <janburse@fastmail.fm> - 2014-11-07 00:07 +0100
                Re: Java 7 vs 8 speed issues on Win7? "Bob(but not" THAĊ˘ "Bob)" <nobody@nowhere.net> - 2014-11-07 08:48 +0000
                Re: Java 7 vs 8 speed issues on Win7? Jan Burse <janburse@fastmail.fm> - 2014-11-08 11:28 +0100
        Re: Java 7 vs 8 speed issues on Win7? Roedy Green <see_website@mindprod.com.invalid> - 2014-11-20 03:12 -0800
          Re: Java 7 vs 8 speed issues on Win7? Silvio <silvio@internet.com> - 2014-11-20 13:24 +0100
            Re: Java 7 vs 8 speed issues on Win7? Robert Klemme <shortcutter@googlemail.com> - 2014-11-20 19:06 +0100
              Re: Java 7 vs 8 speed issues on Win7? Silvio <silvio@internet.com> - 2014-11-20 22:54 +0100
                Re: Java 7 vs 8 speed issues on Win7? Brixomatic <brixomatic@yahoo.com> - 2014-11-22 08:54 +0100
                Re: Java 7 vs 8 speed issues on Win7? Brixomatic <brixomatic@yahoo.com> - 2014-11-22 09:19 +0100
    Re: Java 7 vs 8 speed issues on Win7? Fredrik Jonson <fredrik@jonson.org> - 2014-11-29 07:44 +0000

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