Download more than 2 images at a time

[viv@spotbyte.com]

Hello,

I have a website which is a bit slow:
http://www.webpagetest.org/result/111027_FY_20H6C/

As you can see, there are a lot of images and they are loaded 2 by 2... Is it possible to load them 4 by 4 or more ? What is controlling this ?

Also, the page start rendering before downloading everything, but is it possible to know more or less when ? Well more or less my question is "how to reduce the time before the page start rendering?"

Thanks for your help