I've checked the latency on both the host side (nmon) and at the disk level (statit). I am pretty sure they are ok, reads never go higher than 4ms and writes are in the 1ms range (on disk) and from the AIX side it's not much worse except for a few specific file systems. I want the PAM  II cards for my VMs and shares (other controller) more than Oracle but I wanted to make sure I was not missing a glaring IO problem on the DB side before I got something that does not make any difference for writes.
 
The SATA disks holding my VMs are crying out for PAM relief and like you said it won't (shouldn't) hurt for Oracle. I want to make sure that I am doing due dilligance (as far as I can with out access to the data on the Oracle side anyways) so the folks who I provide storage to are comfortable I am making the right choice.
 
Thanks for all the feedback, I am learning a lot which is always good.

From: Romeo Theriault [mailto:romeotheriault@gmail.com]
Sent: Monday, February 22, 2010 1:39 PM
To: Page, Jeremy
Cc: toasters@mathworks.com
Subject: Re: PAM cards or disks and some questions about the impact of running with PAM



On Tue, Feb 23, 2010 at 1:35 AM, Page, Jeremy <jeremy.page@gilbarco.com> wrote:
I read that, unfortunately I am not at 7.3.2 yet, I do get the counters but the format is a bit old.
 
My disk utilization rarely goes above 25%
 
Here's what I see but since I'm not at 7.3.2 the numbers may be misleading, I don't know.
array01*> stats show -p flexscale-pcs
Instance    Blocks Usage   Hit  Miss Hit Evict Invalidate Insert
---
     ec0   4194304    90 11733  3479  77  1748         57   2236
     ec1   4194304    38  1203  2275  34   343        401   1748

I'm by no means an expert on any of this and it's the first time I really look at PCS data but it certainly seems like at least the first level of cache (ec0) would help things out with a 90% usage and 11,733 hits but on the other hand a max 25% disk utilization doesn't seem very high to me. You also mentioned to me that your cache age is a fairly good size too. So, I'm not really sure. It certainly doesn't seem like a PAM card would hurt, that's for sure.

If the only thing noticing a performance issue is the Oracle DB you might want to look at the latency on those volumes.

stats show -i 3 volume:*:avg_latency

or using Performance Advisor.

Romeo