Questions about Smarty template efficiency

Smarty template efficiency issues! Recently I used the Smarty template and found that file_exists is often used. does this increase the I/O burden? is this inevitable ?, It will not affect the efficiency of the includ Smarty template. the server is much more robust than you think because it needs to translate your template file into a php program!
Recently I used the Smarty template and found that file_exists is often used. does this increase the I/O burden? is it inevitable?

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The server is much stronger than you think.
Because he needs to translate your template file into a php program, include it when using it
So of course, you need to check whether the file exists. In addition, he also needs to check whether your template file has been changed. if so, he will re-translate it into a php program.
If you enable caching, you also need to check whether the cached file exists and whether it is too old. In this way, Jiuding directly uses the cached file or re-generates the cached file.
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Network-related IO, such as echo without buffering