Do you have any settings which throttle your download speeds? I know Steam has this, I presume Origin also does.
Your ISP could also be throttling you for downloads like this - assuming they might want to limit bandwidth for customers to prevent impact to other users sharing local pipe.
However, Speedtests are just a generalization of what you could get, but is not an indication what you should get or will always get from every site. The fact remains that any given page could have different limitations as to how fast you can get data from them.