How big are the PDF files you're getting?
Because the biggest file I have is 95 MB and my laptop can still open it and scroll through it without any delay. (Then again I do have an Intel Core i7)
But like what was previously said, always look up what others have to say about hardware parts, like this would be a CNET review on that CPU you were looking at:
http://reviews.cnet.com/processors/amd-a8-3850/4505-3086_7-34843944.html
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