Dose - Dosage Sizes

[noreason41]

Swim will generally snort his speed (Australian), and after being on it for a month, still doesn't have the best idea of doses.

Swim normally does small lines (between .05 and .1 grams)...and gets a high after a few minutes, however the energetic effect doesn't last more then 30-60minutes.

Swim is wondering whether its because he takes too little (Swim tried doing .05g every 40min, and it didn't work wonders for him), or is speed just not what Swim was expecting?
Swim is also wondering what the maximum amount he can snort at once, and have it all be absorbed, and what the amount required to get 'high' for a period of at least 4 or 5 hours.