Fong Vang <sudoyang at gmail.com> wrote: > What exactly is different between the 32 and 64-bit version > of CentOS 4.2? The kernel (drivers, file system, etc.) is > probably compiled to support 64-bit and probably glibc. It's all about memory models. For more, see my blog: http://thebs413.blogspot.com/2005/10/what-is-x86-64-long-mode-memory-model.html Almost _everything_ in a Linux/x86-64 distro is PAE52 -- 52-bit Processor Address Extensions (PAE) aka "Long Mode." The kernel, GLibC, all /lib64, /usr/lib64, etc... The PAE52 kernel can also still run PAE36 (36-bit PAE) and 32-bit applications. Hence why a few 32-bit libraries are still included under /lib, /usr/lib, etc... But PAE52 programs cannot use PAE36 or 32-bit libraries and vice-versa. That's where the issues arise. That's also why we include a few 32-bit libraries, for the few 32-bit programs you might want to run. > What're some important differences between the 32 and 64-bit > version? I'm just trying to get a deeper understanding. It's all about memory models. -- Bryan J. Smith Professional, Technical Annoyance b.j.smith at ieee.org http://thebs413.blogspot.com ---------------------------------------------------- *** Speed doesn't kill, difference in speed does ***