Templates are cached in memory for quick rendering speed. Each template consumes approximately 10 KB.
Similar to the virtual search server cache, templates remain cached in memory until a period of inactivity has elapsed. The template is then dynamically removed from memory until its next use. The first time a template is accessed, therefore, is normally the slowest.
HINT: Too many templates in the template cache can consume a great deal of memory. Try to share templates across sites to minimize the impact on system memory resources.