If you train first thing, timing your caffeine right matters more than how much you have.
Caffeine generally takes 20-45 minutes to start being felt, depending on the format. Have it too early and it's already fading by the time you're warming up; too late and it hasn't kicked in yet for your first sets.
For an early session, that means having it right as you wake up if you're drinking coffee, or a bit closer to your warm-up if you're using a faster-absorbing format like gum.
Neuchu's chewed format tends to be felt sooner than a swallowed coffee, which is why some morning gym-goers use it to line caffeine up closer to when they actually start training. You can find it here.