Jonathan Ryshpan wrote:

Configuring the kernel I came across a choice between generic-x86_64 processors, and the Opteron/Athlon/Hammer/K8 processors. My system has a 4-core Phenom processor. Questions:

 1. Is the Phenom compatible with the Opteron/etc?  I.e. if I
    configure for the Opteron, will my kernel be reliable?  (This is
    not as easy to find out as I thought.)

To my knowledge, yes. It's certainly compatible with the Athlon. I run a Phenom quad-core as well, but I just use the off-the-shelf x86_64 kernel. Works fine.

 2. How much of a performance advantage is there to configuring for
    the Opteron as against the generic?

I don't know that you'd notice any significant difference with a normal work load. If you were doing heavy I/O or number crunching, then you might see some difference, but not enough to really bother making a custom kernel.

That's just my opinion, of course. ---------------------------------------------------------------------- - Rick Stevens, Systems Engineer ricks@nerd.com - - AIM/Skype: therps2 ICQ: 22643734 Yahoo: origrps2 - - - - The light at the end of the tunnel is really an oncoming train. - ----------------------------------------------------------------------

Jonathan Ryshpan wrote:

 2. How much of a performance advantage is there to configuring for
    the Opteron as against the generic?

These options relate to the equivalent gcc options: http://gcc.gnu.org/onlinedocs/gcc/i386-and-x86_002d64-Options.html

“Generic” will change over time: it’s supposed to provide generally good performance on most current processors.

I understand that the Athlon 64 / Opteron / Sempron / Phenom processors are pretty good at making the best of whichever optimisations they get, and there isn’t much difference between the generic optimisations and the AMD-specific ones.

I would expect any performance advantages to fall well within the limits of experimental uncertainty.

Hope this helps,

James.