22-Oct-2007

Introduction

The processor architecture on the RTC is a 64 bit architecture (Itanium-2), referred to by the IA64 designation. Most desktop PCs are 32 bit architecture referred to as IA32, or more generically as x86 or x86-32. Newer 64 bit desktop systems are referred to as x86_64. The x86_64 systems will run 32 bit binary executables without the need to recompile. However, an IA64 system will not run x86 binaries with the following exception as described below.

32 Bit Emulation Mode

The RTC is running an IA64 (64 bit) version of the linux kernel. IA64 systems will not run x86 executable binaries. Binaries compiled on an x86 system will need to be recompiled to run on RTC. However, the login nodes of RTC have 32 bit emulation enabled. This will allow 32 bit x86 binaries to run on the login nodes. This will allow users to test the 32 bit version of their binaries on the RTC before recompiling into IA64 format. This emulation layer introduces a performance degradation and is therefore not enabled on the compute nodes. Anyone who needs to run their own binaries on RTC will need to compile them on RTC before submitting them to a job queue.

Getting Help with a 32 Bit Binary Executable

If it is impossible for you to recompile your binaries on the RTC (i.e. you only have the binary executable and not the source code), please inform the Help Desk. We will discuss with you whether or not we need to enable 32 bit emulation on the compute nodes for your jobs.