RAC or Large SMP...?

I support an OLTP application which handles 2 million transactions per day and is running on 10gR2 EE on RHEL 4 x86_64.

I am investigating scaling options for the application and I'm trying to decide between 2 large SMP servers or a multi-node RAC configuration.

As far as I can tell, the highest number of cores available in an x64_64 server is 24. This would only allow us to handle 6 times the current workload, and realistically we need to be able to support up to 20 times the load.

Has anyone had any experience of comparing the 2 approaches with respect to cost, manageability, performance, etc. Can you offer any advise and/or pointers to resources to help out with this investigation.

Specifically I'm interested in:

What is the most powerful x86_64 machine available..? Can Oracle scale well on NUMA based architectures (as some of the high end x64_64 based servers seem to be)..?
Is the cost difference between '2 x large SMP' and 'multi-node RAC' large enough to justify the extra complexity of administering a cluster environment...?

Any assistance on this would be greatly appreciated.

Thanks Received on Mon Oct 06 2008 - 19:40:46 CDT