RE: Upgrade existing machine or buy new?

Hi James,

First you need to understand why it is slow. When it runs, are you 100% CPU,
or is it idle and you are 100% RAM?

What is the load target for your web application? Is this a 100 user app,
1000 user app, or 10,000 user app?

The older 940x series had pretty slow CPUs in them. I saw some with sub-1Ghz
CPUs in there, which you don't want for PHP. PHP is an interpreted
environment, even with Zend optimizer. That means it will be partially CPU
bound, but like most web applications, it is memory bound.

Without knowing more, you need to:

1. Increase RAM to 1 GB or higher
2. Increase your disk to 100 GB
3. Purchase an IOP card for gigabit Ethernet
4. Upgrade your LAN switch to gigabit throughput

I don't know what comes in the 9406-170, so if you have some of this
already, then good.

Web applications are almost ubiquitously network-i/o bound. Understand how
much data you need to push on your network for each user, and then you will
know if you are network bound, ram bound, or cpu bound.

-- Jake


-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of James Rich
Sent: Monday, February 22, 2010 10:20 AM
To: midrange-l
Subject: Upgrade existing machine or buy new?

Hi everyone,

I have a customer that has a 9406-170 with 256MB main storage and 25.770GB
disk storage. This system is fine for the 25 or so concurrent users most
of the time. Now we are going to install a web application using Zend.
When we run our web app on that system, it is too slow. The customer is
considering a new System i for this reason. What would be the best use of
their money, buy a new System i or upgrade the RAM and add more disk?

They currently are as near as makes no difference to 100% disk usage. The
daily close and backup is taking about 40 minutes longer than they would
like. They are on v5r3m0. An important software factor when considering
v6 and beyond is that they are heavy users of WRKQRY and that isn't going
to change.

Best suggestions?

James Rich

if you want to understand why that is, there are many good books on
the design of operating systems. please pass them along to redmond
when you're done reading them :)
- Paul Davis on ardour-dev