Mikey’s thoughts on Xgrid

8 09 2007

This started off as a small question and ended up being informational, sorry for the ramble. 😉

So i’ve been messing around with Xgrid a bit this morning, seeing what two macbooks (one black, one pro) can do to increase the speed of video conversion.

Took a while to get setup, there doesn’t appear to be any config tool out there. I used the instructions from [url=http://www.macgeekery.com/gspot/2006-06/setting_up_an_xgrid_controller_in_tiger]this[/url] page.

As a speed test, i used visualhub to transcode some video from Mpeg-1 to H.264 (reduces the size by about half).

First run took 29 minutes or therabouts, with Xgrid disabled.
The Xgrid took 11:10 seconds, with a Macbook Pro 2.2Ghz & Macbook 2.0Ghz as Agents.

So quite a considerable increase. 8)

Apparently VisualHub works better on dual core processors with Xgrid enabled, so lastly i gave that a go with only the Macbook Pro assigned to the grid. The time taken was 13:04 – wtf? i had to run this conversion twice to see if it was limited to what i was converting.

Using the same files, the Xgrid made 10.37. Maybe i thought, this is because it’s being done over wireless, but nope, actually a worse result over ethernet.

So theres definitly some overhead involved, as the macbook pro was working hard while the macbook was idle for at least part of the time. In windows it would be termed priority, what is it on a mac? I think the Xgrid controller that’s dishing out jobs has to have a higher priority than the Xgrid agent doing the work, but i’m not sure how to change this. Any ideas?

If you want to do it yourself :
I found a program that allows you to avoid the command line bs .. [url=http://edbaskerville.com/software/xgridlite/]here[/url]. It ads a system preferences pane to allow you to start / stop / set passwords, which IMHO should be able to be done by Xgrid Admin. Seems strange to leave it out.

You’ll also want the [url=http://www.apple.com/support/downloads/serveradmintools1047.html]server admin tools[/url] if you want to monitor what your xgrid is doing.

What strikes me as strange is that if i select “Agent accepts tasks only when this computer is idle”, the tasks dont start, because i believe the macbook thinks it’s not idle, as there’s still background processes running.

Works fine when i’ve got it set to ‘agent always accepts tasks’, though 🙂




Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: