I am trying to fix a high PostgreSQL CPU use problem. We are using PostgreSQL 8.0.9 and when our JEE web application (in JBoss) is used in certain load increase conditions, top shows a slow increase in processes for PostgreSQL. When the problem occurs, there are approximately 12-15 PostgreSQL processes all showing SELECT on the far right of the process information and approximately 6-7% CPU usage each and then the app slows down a lot.
JBoss version: JBoss (MX MicroKernel) 4.0.3
Operating system: CentOS Linux 5.5
Kernel and CPU: Linux 2.6.18-194.26.1.el5 on x86_64
Processor information: 2 x Intel(R) Xeon(R) CPU E5420 @ 2.50GHz, 8 cores
Currently, our thought is to throw more hardware at it. If we do this, would the best option be something like Option A below or Option B?
Option A: 4 x AMD Opteron™ 6100 Series Processors each with 12 Cores
Option B: 4 x Intel® Xeon® 7500 series Processors each with 8 Cores
Is it correct to assume that CentOS Linux 5.5 with PostgreSQL 8.0.9 will scale proportionately with the addition of this many processors and cores (Ex. 4 processors each with 12 cores)? Is there something else I should consider in terms of throwing more hardware at it?