Performance compared to Java Types

Performance comparison with Java BigDecimal and double (primitive)

The purpose of this performance test is to measure how big is the penalty for using Decimal against BigDecimal, and how does it relate to primitives.

The short summary, out of many executions I have found that

Decimal takes 1.18 times longer than BigDecimal
Decimal takes 84.69 times longer than Double

If you are interested, read on…

Execution environment:

Processor Name: Intel Core 2 Duo
Processor Speed: 2.4 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 3 MB
Memory: 4 GB
Bus Speed: 1.07 GHz

java.runtime.name : [Java™ SE Runtime Environment]
java.specification.version : [1.6]
java.version : [1.6.0_15]
java.runtime.version : [1.6.0_15-b03-226]
java.vm.vendor : [Apple Inc.]
java.vm.name : [Java HotSpot™ 64-Bit Server VM]
java.vm.version : [14.1-b02-92]
java.vm.specification.vendor : [Sun Microsystems Inc.]
java.vm.info : [mixed mode]
java.class.version : [50.0]
sun.arch.data.model : ⁶⁴
sun.management.compiler : [HotSpot 64-Bit Server Compiler]
Operating system: [Mac OS X x86_64][10.5.8]
Available processors: 2

Simple test, minimum requirements, no gc calls.

-mx=256 -mX=512

Summary:

Class	Mean	Std. Deviation
Decimal	1.599 μs	1.083 μs
BigDecimal	1.145 μs	637.803 ns
Double	23.314 ns	7.223 ns

Delta from Java types

Decimal Delta	Mean	Std. Deviation
BigDecimal	454.096 ns	445.203 ns
Double	1.576 μs	1.076 μs

Increased memory size, and gc calls between tests.

Performing a System.gc() call and waiting for 2 seconds in between each test revealed that only in the case of division, the memory usage seems to increase, while performing almost 30% faster.

-mx=256 -mX=1024

Summary:

Class	Mean	Std. Deviation
Decimal	1.095 μs	309.101 ns
BigDecimal	689.357 ns	275.052 ns
Double	15.613 ns	6.013 ns

Delta from Java types…

Decimal delta	Mean	Std. Deviation
BigDecimal	405.288 ns	34.049 ns
Double	1.079 μs	303.088 ns

Output:

Performance tests for Quantify: Sun Oct 04 14:47:44 BST 2009
Creating dataset with 1000000 random numbers:
Finished creating data, sleeping…
Ready to start!

BigDecimal operation: Plus
613.063 ns
Memory allocated: 277.545 mb
Memory free: 50.892 mb
Delta: 226.653 mb
BigDecimal operation: Minus
599.455 ns
Memory allocated: 399.286 mb
Memory free: 105.216 mb
Delta: 294.071 mb
BigDecimal operation: Multiply:
1.143 μs
Memory allocated: 399.286 mb
Memory free: 10.181 mb
Delta: 389.105 mb
BigDecimal operation: Divide:
401.713 ns
Memory allocated: 542.429 mb
Memory free: 153.543 mb
Delta: 388.886 mb
Decimal operation: Plus:
762.157 ns
Memory allocated: 542.429 mb
Memory free: 223.206 mb
Delta: 319.223 mb
Decimal operation: Minus:
833.229 ns
Memory allocated: 542.429 mb
Memory free: 189.769 mb
Delta: 352.660 mb
Decimal operation: Times:
1.508 μs
Memory allocated: 542.429 mb
Memory free: 110.508 mb
Delta: 431.921 mb
Decimal operation: By:
1.276 μs
Memory allocated: 585.196 mb
Memory free: 154.888 mb
Delta: 430.308 mb
Double operation: Plus:
14.358 ns
Memory allocated: 585.196 mb
Memory free: 319.853 mb
Delta: 265.343 mb
Double operation: Minus:
10.852 ns
Memory allocated: 585.196 mb
Memory free: 392.076 mb
Delta: 193.119 mb
Double operation: Times:
11.471 ns
Memory allocated: 585.196 mb
Memory free: 392.223 mb
Delta: 192.972 mb
Double operation: divide:
25.772 ns
Memory allocated: 585.196 mb
Memory free: 392.320 mb
Delta: 192.875 mb

Without GC between tests

Summary:

Class	Mean	Std. Deviation
Decimal	1.260 μs	331.063 ns
BigDecimal	730.944 ns	318.733 ns
Double	24.010 ns	11.663 ns

Delta from Java types…

Decimal diff	Mean	Std. Deviation
BigDecimal	528.698 ns	12.330 ns
Double	1.236 μs	319.399 ns

Output:

Performance tests for Quantify: Sun Oct 04 22:48:38 BST 2009
Creating dataset with 1000000 random numbers:
Finished creating data, sleeping 15 seconds…
System load average: 55.57%
Ready to start!
BigDecimal operation: Add:
Execution finished in 629.410 ns
Memory allocated: 316.314 mb
Memory free: 93.962 mb
Delta: 222.352 mb
BigDecimal operation: Subtract:
Execution finished in 530.287 ns
Memory allocated: 316.314 mb
Memory free: 29.307 mb
Delta: 287.006 mb
BigDecimal operation: Multiply:
Execution finished in 1.276 μs
Memory allocated: 423.662 mb
Memory free: 13.303 mb
Delta: 410.358 mb
BigDecimal operation: Divide:
Execution finished in 488.257 ns
Memory allocated: 469.275 mb
Memory free: 7.888 mb
Delta: 461.387 mb
Decimal operation: Plus:
Execution finished in 923.894 ns
Memory allocated: 545.755 mb
Memory free: 15.403 mb
Delta: 530.352 mb
Decimal operation: Minus:
Execution finished in 947.733 ns
Memory allocated: 615.944 mb
Memory free: 4.688 mb
Delta: 611.256 mb
Decimal operation: Times:
Execution finished in 1.680 μs
Memory allocated: 783.061 mb
Memory free: 26.437 mb
Delta: 756.624 mb
Decimal operation: By:
Execution finished in 1.487 μs
Memory allocated: 855.806 mb
Memory free: 20.755 mb
Delta: 835.051 mb
Double operation: Plus:
Execution finished in 10.895 ns
Memory allocated: 855.806 mb
Memory free: 20.755 mb
Delta: 835.051 mb
Double operation: Minus:
Execution finished in 26.570 ns
Memory allocated: 855.806 mb
Memory free: 20.755 mb
Delta: 835.051 mb
Double operation: Times:
Execution finished in 16.839 ns
Memory allocated: 855.806 mb
Memory free: 20.755 mb
Delta: 835.051 mb
Double operation: Divide:
Execution finished in 41.734 ns
Memory allocated: 855.806 mb
Memory free: 20.755 mb
Delta: 835.051 mb

System load average: 77.69%
Execution finished in 8.120 s

Without storing the results in arrays

Summary:

Class	Mean	Std. Deviation
Decimal	233.683 ns	98.245 ns
BigDecimal	154.565 ns	44.101 ns
Double	2.658 ns	0.095 ns

Delta from Java types…

Decimal diff	Mean	Std. Deviation
BigDecimal	79.118 ns	54.144 ns
Double	231.025 ns	98.150 ns

Decimal takes 1.51 times longer than BigDecimal
Decimal takes 87.91 times longer than Double

System load average: 39.06%
Execution finished in 1.637 s

Performance tests for Quantify: Sun Oct 04 23:32:02 BST 2009
Creating dataset with 1000000 random numbers:
Finished creating data, sleeping 15 seconds…
System load average: 39.06%
Ready to start!
BigDecimal operation: Add:
Execution finished in 151.630 ns
BigDecimal operation: Subtract:
Execution finished in 140.417 ns
BigDecimal operation: Multiply:
Execution finished in 224.036 ns
BigDecimal operation: Divide:
Execution finished in 102.177 ns
Decimal operation: Plus:
Execution finished in 141.804 ns
Decimal operation: Minus:
Execution finished in 169.173 ns
Decimal operation: Times:
Execution finished in 228.883 ns
Decimal operation: By:
Execution finished in 394.872 ns
Double operation: Plus:
Execution finished in 2.612 ns
Double operation: Minus:
Execution finished in 2.724 ns
Double operation: Times:
Execution finished in 2.527 ns
Double operation: Divide:
Execution finished in 2.770 ns