Java 8 vs Java 17 – Performance
- Garbage Collection: Java 17 adds ZGC, Shenandoah, and improved G1 GC.
- Heap Scalability: Java 17 supports terabyte-scale heaps; Java 8 is limited.
- Startup Time: Java 17 offers faster application startup than Java 8.
- JVM Optimizations: Java 17 includes better JIT compilers and monitoring tools.
- Language Features: Java 17 introduces pattern matching and records for efficiency.
Java 8 vs Java 17 – Performance

Java has evolved significantly over the years, with each new release introducing enhancements that improve performance, scalability, and developer productivity. Java 8, released in 2014, was a revolutionary update that brought major changes, including lambdas, the Stream API, and default methods.
Java 17, released in 2021, builds on these foundations with various modern improvements, especially in performance. These advancements address critical areas like garbage collection, JVM optimizations, language features, and hardware compatibility, making Java 17 far more robust and efficient than Java 8.
This article highlights the key performance differences between Java 8 and Java 17, focusing on garbage collection, JVM optimizations, and language enhancements.
1. Garbage Collection Improvements
Garbage Collection (GC) plays a critical role in Java’s performance by automatically managing memory. Java 17 introduces advanced GC mechanisms that significantly outperform the options available in Java 8, addressing issues like pause times, scalability, and heap fragmentation.
Java 8 Garbage Collectors:
- Parallel GC (Default): Optimized for throughput but can lead to long pause times during major garbage collection cycles.
- Concurrent Mark-Sweep (CMS): Provides low-latency performance by performing concurrent tasks but suffers from heap fragmentation and frequent Full GC cycles.
Java 17 Garbage Collectors:
- G1 GC (Default): Focuses on balancing low latency and high throughput using a region-based collection strategy, reducing stop-the-world events.
- Z Garbage Collector (ZGC): Delivers sub-millisecond pause times and supports massive heaps, scaling to terabytes.
- Shenandoah GC: Reduces pause times by performing concurrent heap compaction, making it suitable for latency-sensitive workloads.
Performance Impact:
- Java 17’s garbage collectors provide more predictable pause times and better scalability for modern, large-scale applications. For example, ZGC can efficiently handle terabyte-scale heaps, a capability beyond Java 8’s CMS or Parallel GC.
- Shenandoah and ZGC’s concurrent compaction ensures consistent application performance, making Java 17 a superior choice for real-time systems.
2. JVM Optimizations
Between Java 8 and Java 17, the Java Virtual Machine (JVM) significantly improved, resulting in better runtime performance, enhanced monitoring capabilities, and reduced overhead for large applications.
Key JVM Enhancements in Java 17:
- Improved JIT Compilers: The Just-In-Time (JIT) compiler in Java 17 incorporates better optimizations, resulting in faster execution times for complex computations and loop-intensive operations.
- Enhanced Monitoring Tools: Java Flight Recorder (JFR) and new JFR events in Java 17 provide improved diagnostics with minimal performance impact.
- Sealed Classes and Records: These additions help the JVM optimize memory usage and streamline execution paths by reducing runtime checks for class hierarchies.
Performance Impact:
- Applications running on Java 17 experience faster startup times, reduced CPU usage, and better memory utilization. The enhanced JIT compiler optimizes code paths dynamically, improving runtime efficiency for diverse workloads.
- Developers can identify bottlenecks more effectively using JFR, ensuring smoother application performance.
Read a comparison of Java 8 and Java 17 with garbage collections.
3. Language and API Enhancements
While JVM-level changes drive performance improvements, language and API enhancements also play a pivotal role in improving coding efficiency and runtime behavior.
Java 8 Features:
- Lambda Expressions: Simplify functional programming but may introduce overhead in large-scale lambda-heavy applications due to limited optimization in earlier JVM versions.
- Stream API: Speeds up collection processing but can lead to performance bottlenecks if misused.
Java 17 Features:
- Pattern Matching for Instanceof: Simplifies type checks, making code more concise and improving runtime efficiency.
- Text Blocks: Streamlines handling multi-line strings, reducing computational overhead from concatenation.
- Compact Number Formatting: Optimizes numeric operations by reducing the processing time for formatting and localization.
Performance Impact:
- Java 17’s streamlined language features enable developers to write cleaner, more efficient code, reducing computational overhead and improving maintainability. These changes indirectly boost runtime performance by reducing unnecessary processing.
4. Improved Native Interfacing
Java 17 introduces the Foreign Function and Memory API (Preview) to improve interaction with native code, offering a modern alternative to the outdated Java Native Interface (JNI).
Performance Benefits:
- Faster and more direct access to native memory compared to JNI, reducing overhead for memory-intensive operations.
- Enhanced cross-language integration support enables performance-critical applications to seamlessly interface with C libraries or other native codebases.
5. Security Enhancements
Improved security mechanisms in Java 17 indirectly contribute to better performance by reducing runtime vulnerabilities and the overhead of patching.
Key Improvements:
- Stronger Cryptography Algorithms: Optimized cryptographic functions reduce processing delays in security-sensitive applications.
- Context-Specific Deserialization Filters: Prevent vulnerabilities while maintaining efficient object deserialization.
Performance Impact:
- Applications benefit from better runtime security with minimal impact on processing speed, ensuring a balance between safety and efficiency.
6. Better Support for Modern Hardware
Java 17’s JVM has been optimized to leverage modern hardware architectures, including multi-core processors and systems with large memory capacities.
Performance Benefits:
- Improved multi-threading capabilities enable efficient parallel processing for high-throughput workloads.
- Optimized memory allocation ensures better utilization of large-scale memory systems, minimizing latency and maximizing application scalability.
Comparison Table: Java 8 vs Java 17 Performance
Feature | Java 8 | Java 17 |
---|---|---|
Default GC | Parallel GC | G1 GC |
Low-Latency GC Options | CMS | ZGC, Shenandoah |
Heap Scalability | Medium-sized heaps | Terabyte-scale heaps |
Language Features | Lambdas, Streams | Pattern Matching, Records |
JVM Monitoring | Basic Tools | Enhanced JFR, Flight Recorder |
Native Interfacing | JNI | Foreign Function and Memory API |
Startup Time | Moderate | Faster |
Security | Basic cryptography | Advanced cryptography and filters |
Conclusion
Java 17 delivers significant performance improvements over Java 8 by introducing modern garbage collectors, advanced JVM optimizations, and language features that enhance runtime efficiency and developer productivity.
For businesses and developers managing large-scale, latency-sensitive, or resource-intensive applications, upgrading to Java 17 offers substantial benefits. Transitioning from Java 8 to Java 17 is a strategic move to harness the latest advancements in Java technology, ensuring better scalability, lower latency, and improved application performance.
FAQ: Difference Between Java 8 and Java 17 – Performance
What is the default garbage collector in Java 8 and Java 17?
Java 8 defaults to Parallel GC, while Java 17 defaults to G1 GC, which offers better predictability of pause time.
Does Java 17 support low-latency garbage collection?
Java 17 includes ZGC and Shenandoah for ultra-low latency applications, absent in Java 8.
Which version handles larger heaps more efficiently?
Java 17 supports terabyte-scale heaps, making it far superior to Java 8 in scalability.
How has the JVM improved in Java 17?
Java 17 features better JIT compilers, enhanced diagnostics with JFR, and improved runtime performance.
What are the key language differences between Java 8 and Java 17?
Java 17 introduces pattern matching, text blocks, and records, enabling cleaner and faster code than Java 8.
Is the startup time faster in Java 17?
Java 17 offers faster startup times due to JVM optimizations and improved garbage collectors.
How do garbage collection pauses compare between Java 8 and Java 17?
Java 17 provides significantly lower and more predictable pause times than Java 8, thanks to ZGC and Shenandoah.
What role does the Foreign Function and Memory API play in Java 17?
It replaces the outdated JNI, offering faster and more efficient native memory access.
Is Java 17 more secure than Java 8?
Java 17 includes stronger cryptographic algorithms and context-specific deserialization filters for improved runtime security.
Can Java 17 handle modern multi-core processors better than Java 8?
Yes, Java 17 is optimized for modern hardware, leveraging multi-threading and better memory allocation.
What makes Java 17 better for real-time systems?
The introduction of ZGC and Shenandoah allows Java 17 to handle real-time workloads with minimal latency.
Does Java 17 support better monitoring tools than Java 8?
Java 17 enhances Java Flight Recorder and introduces more JFR events for better application diagnostics.
How do the language features improve performance in Java 17?
Pattern matching and records in Java 17 reduce runtime checks and improve code execution efficiency.
Is it worth upgrading to Java 17 from Java 8 for performance?
Java 17 offers improved garbage collection, scalability, and modern features that significantly enhance performance.
What industries benefit most from Java 17\u2019s improvements?
Industries managing large-scale, latency-sensitive, or real-time applications will benefit most from Java 17’s advancements.