noidea_77 :
Try this: http://en.community.dell.com/support-forums/desktop/f/3514/t/19329296.aspx
I remember this post from long time ago, I was looking as well for the same answer, however
czarsun never provided any proof, he just said that it is possible and that is it.
Unfortunately, I seen many people say things like this everywhere, without any proof and as soon as I am finding proof of the opposite, they just disappear.
So, the idea is - try to find the actual proof of someone stated that he/she achieved this or that with Dual CPU on GX620, otherwise OP might get nice paperweight!