Performance with XEON

[Paul Sladen]

On Wed, 24 Nov 2004, David Walker wrote:

[Moved over from  ubuntu-devel@  to here]

Hello David,

> I have recently installed Ubuntu on my XEON based machine.  But, I have 
> been having problems recently.  For an unknown reason the machine is not 
> performing well at all.

Could you describe how it is 'not performing well'.  Is there any particular
task that you can time and compare it to any other machines.

For instance, does bootup take 18minutes?

> I do not know why, I did the same install of warty as my other machines
> (using P4, and AMD).

Are the other machines exactly identical.  What's different about
them---it's quite likely that I/O limitations, or only having 32MB of RAM is
more likely to make a difference than the CPU.

Have you looked at  'top'  to see the CPU usage, or had a look at the system
logs to see if there are any timeouts or other problems reported:

  sudo tail -f /var/log/messages

> I am wondering if there is a known problem why it should not be
> performing well.

I do not believe so, if you've found something, we'd like to track it down.

As somebody else suggested, you sometimes get a small (5%-10%) increase in
raw CPU performance if you're running multiple programs and can make sure of
the Hyper-Threading (HT) in the Xeon chips.

You'll need in install the SMP (Multi-processor) kernel for this, but the
difference is generally so small that if you notice it's appearing slow you
won't be able to notice the gain.

	-Paul
-- 
Is there no safe way to travel?  Nottingham, GB