Most modern browsers default to two simultaneous threads per hostname. This leads to overhead and latency as the browser will only grab two objects at a time. One of the biggest pitfalls of vBulletin (especially 4.0) is the amount of graphics and javascript served from the same hostname. Setting up parallel hostnames is fairly simple and I’ll outline the steps on a cPanel installation and vBulletin 4.0 stylevars system. The entire process doesn’t take more than 15 minutes even for novice users, and you can easily do more to further optimize your vBulletin.

I’ll assume you’ve got vBulletin 4 installed and configured already. Lets get started then…

First login to cPanel for your domain and go to the subdomains section.

cpanel-subdomains

Setup a new subdomain. You can set the subdomain name to anything you want. In my example I just use images1 images2 etc. You could use a more descriptive subdomain name to keep things easy to remember (ex: clientscript.domain.com). For the document root, point it to your images directory you want to serve from a different subdomain. In the example I’ve used the images/cms folder for this one.

subdomain-cms-vbulletin

Next you’ll need to login to your adminCP for vBulletin 4, click on Styles & Templates -> Style Manager -> {Your Skin} from the drop down menu select “StyleVars”

vbulletin-stylemanage-stylevars

Once your in the new StlyeVars system, click on “Image Paths” over on the left. It’s easier if you also check the hide variables so you can find it easier.

stylevars-imagepaths

Once you’re there you’ll notice all the different folders that serve images. I suggest creating a subdomain for each folder that serves images, in the picture above you can kinda see that I have a few already setup. The next step is to enter the newly created subdomain as the full path for the image directory. Since I created the images5.domain.com and pointed it to the cms folder of images, I enter that into the cms field.

stylevars-imagepaths-vbulletin-parrel

You simply repeat this for each image directory and you’ll have your vBulletin 4 optimized and little overhead due to objects on the page.  You can see that I’ve got a few already setup and it improved my google page load score from a 66 to almost 79 by adding all the image directories this way.

cpanel-subdomain-list

BONUS TIP:

You can futher optimize by following the above by doing the same for the clientscript folder. As shown above I created clientscript.subdomain.com and pointed it to the clientscript folder. Then I modifed the headinclude template and changed the location of the clientscript call.