Hi John, I am with Joe regarding looking at the interrupts. >
That was one of my initial thoughts, too, but I haven't really dug into their states yet. I'm going to start keeping an eye on them now. > However, could this be a difference with the power management with the > Redhat kernel? > ie. when running on 8 cores you are tripping over some thermal threshold > and causing a throttle back to a lower C-state? > This is something I hadn't thought of but which makes a lot of sense, and in my reply to Joe, you'll see we've got a power-saving state selected for the PCIe ASPM. I'm going to see if our guys can turn that off and whether that helps, and I'll poke around some of the other tunable power options soon, too. I don't have root access and sit more on the application side so I'm a bit rusty on all the buttons and dials, but I'll investigate a bit and report back what I find. > Can you give the kernel versions for both setups? > The C5.5 kernel is 2.6.18-194 The R6.2 kernel is 2.6.32-220 There's a few more kernels in the mix now, but I'd like to check out a few other things before I add to the confusion. ;-) Thanks again, - Brian
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