PowerVM™ Lx86 runs most x86 Linux® applications, but PowerVM Lx86 cannot run applications that:
- Directly access hardware devices (e.g. 3D graphics adapters);
- Require nonstandard kernel module access or use kernel modules not provided by the Linux on POWER™ operating system distribution;
- Do not use only the Intel® IA-32 instruction set architecture as defined by the 1997 Intel Architecture Software Developer's Manual consisting of Basic Architecture (Order Number 243190), Instruction Set Reference Manual (Order Number 243191) and the System Programming Guide (Order Number 243192) dated 1997;
- Do not run correctly on Red Hat Enterprise Linux 4 starting with version 4.3 or Novell SUSE Linux Enterprise Server (SLES) 9 starting with version SP3 or Novell SLES 10;
- Are x86 Linux specific system administration or configuration tools.
In addition, the performance of some x86 Linux applications running on PowerVM Lx86 may significantly vary from the performance obtained when these applications are run as a native port. There are various architectural differences between x86 and POWER processors which can impact performance of translated applications. For example, translating dynamically generated code like Java™ byte codes is an ongoing translation process, which can be expected to impact the performance of x86 Java applications using an x86 Java virtual machine. Floating point applications running under x86 have a different default precision level from Power Architecture™ processors, so translating between these levels can have additional performance penalties. And finally, translating and protecting multi-threaded applications can incur an additional performance overhead as the translator works to manage shared memory accesses. IBM suggests that clients carefully consider these performance characteristics when selecting the best method for enabling applications for their environment.