I have a simple about page being rendered with the content of only one entry and some Low Variables bits. It's rather slow (3.8806 seconds according to the Output Profiler), and the Template Debugging shows that all possible snippets are being loaded 6 times in each page load. The only number I could correlate with that is the number of templates being rendered in the page (aside from the main page, there's embedded template partials for the header and footer, scripts, etc). Am I correct in assuming that all snippet content is being loaded for every time a template is loaded? Is there any way to make it not do that?
The snippets are not actually "loading" - they are simply bits of text being stored in memory (much like global variables). They aren't actually processed until they're called. So they're not an overhead problem.
You'll see these being "loaded" each time you run the template engine - which means the primary template, and then each embed.