Why isn't this laptop as fast as previous laptop

I used to use a HP G56 3gb 2,1ghz laptop and it ran source games pretty well, minecraft ran quite well as well I played on normal render distance with no problem. 

I am using my friends laptop which is a Acer 4gb 2,4ghz, it does not play games very well, I assumed it would because it is better in pretty much every aspect as my laptop, minecraft runs very slowly, insurgency (very low performance game) runs very badly at lowest graphics, the battery setting is on high performance but does anyone know how to get this laptop running well?

Can you please give the model numbers of the laptops so we can have a more indepth look?

agreed

Aspire 5742

It's not an old laptop either it's not even a year old.

must have gone from discrete graphics to onboard

On minecraft I get 10 - 15 fps on normal render distance, this is ridiculous it has 4gb of ram my 3gb laptop could nearly run on far settings.

yea the Aspire doesn't have a discrete graphics card. 

Doesnt have a discrete card for sure.

Agreed

Ok, but does anyone have any idea why this is happening? I just dont get it, does 'not having a discrete graphics card' cause this much perfomance loss, or is it something  else? 

onboard is good in some situations but bad in others

When you play games your graphics card is the most import piece of hardware in your computer. I dare say it's the bottle neck in 90% of the cases. And descrete graphics is really bad for gaming basically although it's starting to come around on entry models because of apu's and such, but you don't need to bother about that! in short it's your graphic card as has been said.