Help deciding on laptop A8 vs i5

Hi,
so i am getting confused whilst trying to decide what laptop to go for. I was almost decided on this http://www.very.co.uk/lenovo-lenovo-z585-amd-a8-processor-8gb-ram-1tb-hard-drive-156-inch-laptop---metal/1186038623.prd;jsessionid=5DB1A1E243DDF3E023F2FD3C7D055A4B.fts02d:-9?browseToken=%2fb%2f4294951190 which is running an AMD A8

but then i looked up processor benchmarks and the i5 on this one http://www.pcworld.co.uk/gbuk/hp-pavilion-g6-2212sa-15-6-laptop-18093448-pdt.html scored better.

So i know there is always intel vs amd views but those aside what would work better for me.

So i am a web designer, which means i use graphics programs like photoshop CS5.5 or GIMP and i've just started using Blender 3D which is rather intensive. I have access to a powerful desktop if i really need to but this laptop would be my main machine (yes i know they aren't the best money can buy but thats my budget right now)

I would probably keep windows 8 on there but look at dual boot with ubuntu a lot of the time.

i've read a lot of forums comparing the 2 but they haven't swayed me one way or the other.

I read that the A8 is not a true quad core? confused. Also i had a feeling i read that some programs run better on a fast dual core than on a quad core as they can't use all the cores? is that right? and if so with the types of things i will be doing is dual or quad better.

thanks