To be clear – are you talking about the actual TTFB or are you talking about the full page load?
If you’re talking about the TTFB – usually a delay that long means you’re running a complex script, such as WordPress with many plugins and no caching. If you’re talking about the page loading – 1 second is totally reasonable depending on how much data you’re sending to the browser.
More information about your site and hosting would be helpful to make a more informed recommendation rather than random guesses that may or may not apply.