1. An Empirical Analysis of Java Performance Quality
Simon Chow

2. Objectives
See if we can enhance the performance of Java applications without modifying the Java code directly
Perform test runs with SPECjvm benchmarks to determine the performance quality of the computer

3. SpecJVM and its Benchmarks
A benchmark suite that measures a computer system’s performance through its Java Runtime Environment
Serial Benchmark
Derby Benchmark
Sunflow benchmark
Each benchmark has a warmup and iteration phase

4. Parameters Used For SpecJVM Runs
Adjusting Memory Heap Size:
–Xmx1g
-Xmx2g
–Xmx3g
For tuning garbage collection:
G1GC
ConcMarkSweep
Parallel

5. Serial Performance vs Heap Memory Size Data
Performance (op/min)
Java Parameter
Trial 1
Trial 2
Trial 3
Average
None
86.51
87.37
94.46
89.45
"-Xmx1g"
85.82
98.74
79.45
88.00
"-Xmx2g
83.70
97.67
75.86
85.74
"-Xmx3g
86.06
96.94
95.67
92.89

7. Derby Performance vs Heap Memory Size Data
Performance (op/min)
Java Parameter
Trial 1
Trial 2
Average
None
267.99
257.27
262.63
"-Xmx1g"
230.48
265.54
248.01
"-Xmx2g
225.02
241.62
233.32
"-Xmx3g
210.65
260.13
235.39

9. Garbage Collection Types With Serial Benchmark
Performance (op/min)
Java Parameter
Trial 1
Trial 2
Trial 3
Average
None
94.31
96.20
91.49
94.00 G1
94.18
87.69
96.59
92.82
MarkSweep
90.00
96.28
94.73
93.67
Parallel
96.26
98.52
94.66
96.48

10. Garbage Collection Types With Derby Benchmark
Performance (op/min)
Java Parameter
Trial 1
Trial 2
Trial 3
Average
None
282.95
299.14
284.41
288.33 G1
303.54
298.83
312.73
305.03
MarkSweep
285.29
259.12
275.20
273.20
Parallel
253.10
284.79
275.78
271.22

11. Garbage Collection Types With Sunflow Benchmark
Performance (op/min)
Java Parameter
Trial 1
Trial 2
Trial 3
Average
None
46.76
47.73
46.93
47.14 G1
47.19
49.93
51.09
49.40
MarkSweep
50.05
46.99
43.16
46.73
Parallel
44.31
41.80
43.33
43.15

12. Conclusions
Modifying the memory heap size parameter seems to have little to no effect on the Java performance
For the garbage collection options, it appears that the G1 garbage collection is faster than both Parallel and MarkSweep

13. Next Steps Test lower heap memory sizes (i.e 500 MB)
Perform further analysis on the garbage collection data to better observe their differences in performance

14. Questions ?