Apache Configuration HTTPS

IE8 often pop up such warning window, Baidu to the information said configuration under IE on line, in the end is not my HTTPS configuration problem?
and is https consuming more resources than HTTP? It feels much slower than before to configure HTTPS.

Reply to discussion (solution)

... What about people?

This warning box is generated by the browser
In the absence of a certificate, this warning is issued when you move from an HTTPS page to an HTTP page

Can HTTPS be optimized? It feels like the website is much slower than before ....

HTTPS needs to do security verification, but also to do encrypted transmission, slow is normal

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