Java and RPi - continued

After I had installed both jdk (open and oracle's), I started wondering what is the difference between them, when it comes to performance. Recently I found some time in the evening and wrote simple tests, which are not very accurate, but give the general notion about performance.

Let's take a look into tests:
ArrayListAppendTest

List<Long> list = new ArrayList<Long>();
for (long l = 0; l <1000000; l++) {
   list.add(l);
}

ArrayListInsertMiddleTest

List<Long> list = new ArrayList<Long>();
for (long l = 0; l < 1000; l++) {
   list.add(l);
}
for (long l = 0; l < 10000; l++) {
   list.add(500, l);
} 

ArrayListSortTest

List list = new ArrayList();
for (int i = 100000; i > 0; i--) {
   String str = String.format("String nr %5s", i);
   list.add(str);
}
Collections.sort(list);

LinkedListAppendTest, LinkedListInsertMiddleTest, LinkedListSortTest are exactly the same as for ArrayList, but with subtle change...

DoubleAddTest

double val = 0.0;
for (int i = 0; i< 1000000; i++) {
   val += (double) i;
}

SinusTest

for(int i = 0; i < 1000000; i++) {
   double val = Math.sin((double) i);
}

StringAppendTest

String [] strings = new String[1000];
for (int i = 0; i < strings.length; i++) {
   strings[i] = String.format("Str %d", i);
}
String concat = "";
for (int i = 0; i < strings.length; i++) {
   concat += strings[i];
}

All tests *ISTest use various input streams, *OSTest - output streams.

When it comes to reflection tests, I tried to instantiate class using classe's newInstance method, in case of CallMethod test I'm calling one argument method using reflection. Simple...

For comparison I executed test on my ancient computer (Amd64 3500+). After that I compiled and run tests on Raspberry Pi using proper JDK.

And the resulst are... interesting (execution time is in ms):

Test name	JDK Oracle 1.7 @ AMD64 3500	Oracle JDK 1.8 ea @ RPi	Open JDK 1.7 @ RPi	Ratio
ArrayListAppendTest	348,6	2632	10965,1	4,2
ArrayListInsertMiddleTest	72,6	285,7	1024,7	3,6
ArrayListSortTest	19,6	292,9	2394,4	8,2
BufferedFileOS	12,2	45,4	856,4	18,9
DoubleAddTest	0,2	35,8	390,5	10,9
FileISTest	25,3	183,8	231,5	1,3
FileOSTest	96,8	524,9	1618,9	3,1
LinkedListAppendTest	636,1	3393,7	16634,3	4,9
LinkedListInsertMiddleTest	23,3	99,5	2159	21,7
LinkedListSortTest	44,8	270,9	2225,9	8,2
ReflectionCallMethodTest	116,3	803,2	3496,7	4,4
ReflectionNewInstanceTest	55,5	202,5	542,4	2,7
SinusTest	268,6	562,5	3722	6,6
StringAppendTest	49,3	254,4	489,1	1,9

As you can see Open JDK in those test is far behind oracle's (in column Ratio you can see, how much slower Open JDK was :/).
I think I stick to JDK 1.8 ea...