high efficiency or high compatibility?

[fzxbeetle]

please have a look at this threat first.Thanks!
http://www.wilderssecurity.com/showthread.php?p=483648#post483648

What is the different between the two setting?

Why it seems high efficiency is more secure?

How can I remove the download windows when using high compatiblity as I using a slow internet connection.

Thanks for your reply.

[fzxbeetle]

just check Blackspear's setting threat. I can remove the windows now. Thanks