what is a hybrid crossfire?

[moroccan]

i have an hd 3450 pci-E 512 mb and i heard in a comment for the seem card graphic that a hybrid crossfire will improve it !!!!! can someone help to clear this for me ? and another question i used overdrive but after i do it a message told me that it is a little bit dangerous (that's what i understand from it ) can someone explain this overdrive thing too ? plzzzzzzzzzzzzzzzzzzzzzzz
if you need information about my pc just put this in google HP Pavilion Slimline s3422.uk

[ultima]

hybrid graphics was something ati came up with for use with intergrated
video, i had only seen it for AMD chipsets though, so i'm not sure
that combining your ati card with the nvidia chipset will work

http://www.anandtech.com/video/showdoc.aspx?i=3178

some charts

3450 alone , integrated alone and combined results
http://www.tomshardware.com/reviews/...t,1785-11.html