On Thursday 08 September 2005 10:49, Tony Schreiner wrote: > What is the maximum number of AMD64 cores supported by CentOS 4? > > The RedHat page https://www.redhat.com/software/rhel/configuration/ > > suggests that RHEL 4 AS supports up to 8 AMD64/EM64T logical cpus. Is > that accurate and does it apply to CentOS 4? > > I see a few vendors offering boxes with 8 (dual core) CPU sockets. > IWILL for one. The suggestion of 8 was made mostly because there was no larger x86-64 platform available at that time. Also, the main reason for the limit is scalability. With more cpus comes more communications overhead, more congestion on the bus, less memory bandwidth for each cpu and so on. How much that effects you depends on your application. I remember in the good old days when smp was first added to the kernel, people said 2cpu was the max you can have... we ran a few 4way systems back then very effectivly simply because our application had only a low volume of communications. Peter.