If you've never done DMT it's far more difficult to point out how different they are, the only describable difference is that DMT leaves you with an incredible feeling of peace for the rest of the day while salvia has a jarring comedown that can often leave you feeling shaken and anti-social.

Both gave me a feeling of deja vu which created in me the belief that I was not exploring some strange realty but returning to somewhere I've been before and had forgotten about. It may just be a random side-effect of the chemical make-up of them, and I figured this about salvia for a long period of time until I tried DMT and realized there was so much more going on in the mind/universe than I even thought possible.