Improvements in Java 7.0, Java 7.1, and Java 8

Java 7.0 uses hardware instructions that were introduced in the IBM zEnterprise 196 (z196) and the IBM zEnterprise EC12 (zEC12) machines. When running on a zEC12, the JVM also uses the new transactional memory capabilities of the hardware.

Java 7.1 extends the zEC12 exploitation by using technologies, such as IBM z Systems Data Compression (zEDC) for zip acceleration. Java 7.1 SR3 introduces improved zIIP-offload characteristics, which can reduce cost for Java applications in CICS.

Java 8 introduces the use of hardware instructions that were introduced in the IBM z13 machine. Also used are technologies, such as single instruction multiple data (SIMD) instructions and improved cryptographic performance that uses Crypto Express5S and CP Assist for Cryptographic Function (CPACF).

The IBM Java Crypto Engine (JCE) in Java 8 SR1 automatically detects and uses an on-core hardware cryptographic accelerator that is available through the CPACF. It also uses the SIMD vector engine that is available in the IBM z13 to provide industry-leading security performance. CPACF instructions are used to accelerate the following cryptographic functions:

• Symmetric key algorithms (AES, 3DES and DES with CBC, CFB and OBF modes)
• Hashing (SHA1 and SHA2)

Optimized routines accelerate the popular P256 NIST Elliptic Curve (ECC) Public Key Agreement. SIMD instructions are used in these routines to further enhance performance.

Java 8 SR2 also introduces the same improved zIIP-offload characteristics as seen in Java 7.1 SR3.