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Hardware Tips

Looking for Zing? The Azul Zing Virtual Machine is now Azul Zulu Prime Builds of OpenJDK and part of Azul Platform Prime. Learn more.

Consider the following recommendations related to the Azul Platform Prime hardware requirements.

Limitation

Description

Recommendation

Processor support insufficient for Azul Platform Prime (constant_tsc support required)

Azul Platform Prime requires a specific feature of modern X86 chips in order to function properly. This feature, constant_tsc, provides a reliable, fast time-source even in the presence of power-saving operations performed by modern processors. This reliable time source is required by Azul Platform Prime.

Solution:

Run Azul Platform Prime on a processor supporting constant_tsc. Nearly all server-class X86 processors made in the last five years have this feature. See the Azul Platform Prime System Requirements and Compatibility References for a list of supported processors.

Known Intel chip errata can cause spurious system-wide delays.

Recent Intel chips in combination with some aggressive power-saving driver techniques are known to cause sporadic system lockups, up to a minute long. This is an issue which can occur with or without Azul Platform Prime present but can be more noticeably manifest in the high-performance, low-latency applications commonly deployed in Azul Platform Prime environments.

This issue appears with RedHat Enterprise Linux 6.1 and its integrated Intel Idle Driver. The Intel Idle Driver aims to improve power efficiency but can lead to system lockups when run on some recent Intel CPUs (some Nehalems and Westmeres have been reported to have problems). Note that this issue does not occur on all Nehalem and Westmere processors.

Solution:

To solve the issue, you can simply boot your system with the Intel idle driver disabled. To do so, modify your kernel boot parameters and add the argument intel_idle.max_cstate=0 to the boot line. See Disabling the Intel Idle Driver for directions on RHEL, SUSE, and Ubuntu systems.