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From Peter Ondruška <peter.ondruska+de...@kaibo.eu>
Subject Re: performance issue on 64 bit JVM
Date Fri, 03 Jun 2011 08:54:50 GMT
Unless you need to address heap over 32bit JVM limits use 32bit JVM.
Just my EUR .02 :-)

2011/6/3 Arnaud Masson <amasson@gmail.com>:
> 64-bit uses more memory,
> so if your Xmx is too small,
> the 64-bit version may have more GC overhead.
>
> You can increase Xmx
> or activate "compressed-pointers" to have a better memory usage.
>
> (Also the max heap size must fit in physical memory, otherwise the swap
> on disk could kill perfs.)
>
>
> Le 03/06/2011 04:09, QA Wang Yang a écrit :
>> Dear Derby
>>
>> Could you tell me how tuning the performance issue?
>>
>> This is running sample query to fetch data from Derby database
>>
>> On my dual-core XP x-32 laptop the Corporate Overview takes 406(ms).
>> But we saw on the dual quad core it took 22973 (ms).
>>
>> I don't know why the performance became bad on my powerful machine.
>>
>> This is my test detail
>>
>> Query:
>> select * from Customer;
>> select * from product;
>> select * from order;
>> select * from Customer1;
>>
>> Dual-core XP SP3 32 bit,JDK1.6.0_25 32 bit,
>> Dual quad core Windows 2008 64 bit, JDK1.6.0_25 64 bit,
>>
>>
>> *32 bit Dual core
>> Fetched record size: 1413
>> Fetch record time: 250 (ms)
>> Fetched record size 8
>> Fetch record time: 15 (ms)
>> Fetched record size: 6
>> Fetch record time: 0 (ms)
>> Fetched record size: 1413 records
>> Fetch record time: 141 (ms)
>> ====total 406 ms
>>
>> **64 bit Dual quad core
>> Fetched record size: 1413
>> Fetch record time: 11483 (ms)
>> Fetched record size 8
>> Fetch record time: 3 (ms)
>> Fetched record size: 6
>> Fetch record time: 4 (ms)
>> Fetched record size: 1413
>> Fetch record time: 11484 (ms)
>> ====total 22973 ms
>>
>> Thanks a lot
>>
>>
>>
>> Wangyang
>> QA Group
>> Jinfonet Software, Inc.
>>
>> www.jinfonet.com
>> 2nd floor on the east of BEC Theatre
>> 135 Xi Zhi Men Wai Street, Xicheng District Beijing, China 100044
>> yang.wang@support.jinfonet.com
>> 86-10-68316633
>>
>> JReport
>> Embedded Reporting for Java Applications
>>
>>
>>
>
>

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