Java 7 update 5 GC

Question

My java application (high-volume, low-latency on-line transaction betting system) needs to accomplish the least GC pause while to keep acceptable throughput. When I read java 7 G1GC and thought this is what I really want (I also investigated Azul Zing but stop somewhere in the middle of my study).
I got a strange result when I ran a test with java 7 update 5 and compared it with java 7.0 of same test though.
The java commands associating to GC in my test is not complicate. I only specified several of them and let GC to determine the rest for best performance. The GC options are:
java -Xms12288m -Xmx12288m -verbose:gc -XX:+PrintGCDetails -XX:+PrintGCApplicationStoppedTime -XX:+PrintCommandLineFlags -XX:+UseG1GC -XX:MaxGCPauseMillis=100 \
The java 7.0 result as following:
java version "1.7.0"
Java(TM) SE Runtime Environment (build 1.7.0-b147)
Java HotSpot(TM) 64-Bit Server VM (build 21.0-b17, mixed mode)
[INFO] total GC times:199
[INFO] C:/Users/Chris/Documents/My Projects/citibet-2nd/support/matchspace/GC performance/XX_UseG1GC_MaxGCPauseMillis100.txt average GC:0.067739 second
[INFO] app stops:206, average seconds:0.065926
[DEBUG] [0.006688, 0.007678, 0.008537, 0.014192, 0.021206, 0.023098, 0.023628, 0.026924, 0.028749, 0.029012, 0.030648, 0.031663, 0.031704, 0.031743, 0.033121,
0.035534, 0.036437, 0.037418, 0.038571, 0.039253, 0.040569, 0.041807, 0.042169, 0.042459, 0.043335, 0.043797, 0.045504, 0.046178, 0.046337, 0.050747, 0.051332,
0.052527, 0.052614, 0.052623, 0.054945, 0.055021, 0.05538, 0.055595, 0.055836, 0.05586, 0.056101, 0.056134, 0.056167, 0.056181, 0.056243, 0.056648, 0.056803,
0.057133, 0.057656, 0.057689, 0.058021, 0.058613, 0.058964, 0.059164, 0.059424, 0.059438, 0.059456, 0.059853, 0.060354, 0.06064, 0.060972, 0.060999, 0.061141,
0.061157, 0.061163, 0.061305, 0.061444, 0.061567, 0.061594, 0.061923, 0.06215, 0.062252, 0.063147, 0.063149, 0.063159, 0.063563, 0.063885, 0.064047, 0.064882,
0.064975, 0.065076, 0.065228, 0.065311, 0.066254, 0.066435, 0.066572, 0.067084, 0.067206, 0.067543, 0.067919, 0.067973, 0.068015, 0.068042, 0.068397, 0.068797,
0.0691, 0.069626, 0.069885, 0.070051, 0.070063, 0.070077, 0.070625, 0.071117, 0.071127, 0.071257, 0.071372, 0.071453, 0.071647, 0.071703, 0.072027, 0.072058,
0.072275, 0.072301, 0.07234, 0.072363, 0.072513, 0.072575, 0.072679, 0.07305, 0.073061, 0.073326, 0.073482, 0.073607, 0.073888, 0.073949, 0.074562, 0.074604,
0.074644, 0.075278, 0.075352, 0.07547, 0.075543, 0.075581, 0.076057, 0.076445, 0.076514, 0.076599, 0.076967, 0.076991, 0.077079, 0.077112, 0.077192, 0.077519,
0.077547, 0.077881, 0.078351, 0.078416, 0.078975, 0.079444, 0.079986, 0.080327, 0.080342, 0.080568, 0.080884, 0.081912, 0.081916, 0.082134, 0.082136, 0.082305,
0.082722, 0.082755, 0.082992, 0.083276, 0.083517, 0.083989, 0.084839, 0.084884, 0.085197, 0.08552, 0.085662, 0.08599, 0.085999, 0.086837, 0.087184, 0.087367,
0.08745, 0.087659, 0.087908, 0.088478, 0.089203, 0.089498, 0.090376, 0.09044, 0.092862, 0.093084, 0.093279, 0.093361, 0.097381, 0.098379, 0.100322, 0.100868,
0.10163, 0.103446, 0.104192, 0.105727, 0.108074, 0.108931, 0.113103, 0.152951]
[INFO] Minimum=11419, Maximum=121219, Total=5204830, Count=66, Average=78861. (total elapsed nano:67824103252)
[INFO] memory in usages after test 101 ends:4111938008, total memory:12884901888, max memory:12884901888 with total 5280000 bets
This test result meets G1GC specified (more GC times but smaller GC pause). While comparing to the test result of java 7 update 5, the result is quite surprised me:
java version "1.7.0_05"
Java(TM) SE Runtime Environment (build 1.7.0_05-b06)
Java HotSpot(TM) 64-Bit Server VM (build 23.1-b03, mixed mode)
[INFO] total GC times:8
[INFO] C:/Users/Chris/Documents/My Projects/citibet-2nd/support/matchspace/GC performance/XX_UseG1GC_MaxGCPauseMillis100_java7u5.txt average GC:0.730325 second
[INFO] app stops:18, average seconds:0.325045
[DEBUG] [0.433048, 0.712155, 0.725535, 0.73903, 0.765341, 0.774686, 0.833398, 0.859405]
[INFO] Minimum=11504, Maximum=175425, Total=5220946, Count=40, Average=130523. (total elapsed nano:43241336678)
[INFO] memory in usages after test 101 ends:5626027848, total memory:12884901888, max memory:12884901888 with total 5280000 bets
The throughput does increase but the GC pause-time does not meet the minimum requirement (< 100 millisecond) quite a big difference!
Again, both runnings use same command GC options. System shows to me like:
-XX:InitialHeapSize=12884901888 -XX:MaxGCPauseMillis=100 -XX:MaxHeapSize=12884901888 -XX:+PrintCommandLineFlags -XX:+PrintGC -XX:+PrintGCApplicationStoppedTime -XX:+PrintGCDetails -XX:+UseCompressedOops -XX:+UseG1GC
Do I miss something secrets when using java 7 update 5 for GC specific issues?

Answer 1

I think this is less about the JRE and more about the browser and its settings. Refer to the Microsoft documentation for more information about how, why, and when the info bar will appear. Here is one example:
http://windows.microsoft.com/en-US/windows7/Internet-Explorer-Information-bar-frequently-asked-questions
Refer to the section that is titled +"When will I see the Information bar?"+ Here are some relevant points from that section which explain when the bar will appear:
<blockquote>•If a website tries to install an ActiveX control on your computer or run an ActiveX control in an unsafe manner.
•If you started Internet Explorer with add-ons disabled.
•If you need to install an updated ActiveX control or add-on program.</blockquote>
Here are more granular details about how the info bar works:
http://technet.microsoft.com/en-us/library/cc782271(v=ws.10).aspx