SEO implications of moving from https to http

[BlueAcorn]

We're considering moving from 100% https to http to improve performance.  What, if any, SEO implications are there?  Do search engines need redirects when changing from https to http pages?

[HalogenDigital]

I've done this exact thing before, and overall it was a breeze. I used the following code in my HTACCESS file, and assuming you're using a standard Apache install this should work for this task nicely:

Options +FollowSymlinks
RewriteEngine on
RewriteCond %{SERVER_PORT} ^443$
RewriteRule ^(.*)$ http://www.yourdomain.com/$1 [R=301,L]

As far as SEO is concerned, this of course means that any existing links will be redirected to the HTTP version, but in my case the knock in rankings was minor at best.

Of course, make sure to update your internal links to make sure you're not redirecting unnecessarily.