Exception on loading large PPTX files

Is there a limitation on PPTX file size? I am receiving this error with relatively small sizes, from 32MB-1GB
 Error: The page was not displayed because the request entity is too large.

Is it related to temporary licensing, or a limitation of the product?

Thanks.

Update: It seems to be related to IIS, but good to know if there is a limit, in theory it should be able to handle 500mb pptx easily in memory.

@sth,

Can you please share source file along with sample code so that we may further investigate to help you out.