Inference configuration parameters of an LLM

Summary

  1. When?: Configuration parameters are invoked at inference time - the decision making time of the output text.
  2. Why?: They help us decide - How creative of an output do we want?
  3. What?: Let’s discuss what options do we have and what are the advantages and disadvantages of each of them.
  4. Types:
    1. Max new tokens: cap of how many tokens to be generated
    2. Greedy vs Random weighted sampling
    3. Top-k & Top-p
    4. Temperature
  5. Let’s dive into each of them in detail:

I. MAX_NEW_TOKEN

  1. Cap on how many tokens to be generated
  2. How short or long do we want our output text
  3. Advantages: As concise or as few words or the opposite we want it to be.
  4. Disadvantages: Can cut short the output

II. Greedy and Random-weighted sampling

  1. Greedy - select words with highest probability

Prob

Word

0.20

cake

0.10

donut

0.02

banana

0.01

apple

…

Word/ token with highest probability is selected

  1. Disadvantages:
    1. Repetitive words
    2. Computer language - not human sounding
  2. Random weights are applied to the probabilities of words

Prob

Word

0.20

cake

0.10

donut

0.02

banana

0.01

apple

…

Banana with lower probability was selected

III. Top-k and Top-p

  1. Top-k: More sensible output
    1. Top ‘k’ words with highest probabilities are selected.
    2. Then random-weighted sampling is applied to the selected words.
    3. Example:
  2. Top-p:
    1. p = cumulative probability
    2. Top words whose cumulative probability is equal to ‘p’ are selected.
    3. Then random-weighted sampling is applied to the selected words.

IV. Temperature

  1. Lower/ cooler (<1)
    1. Strongly peaked probability distribution
    2. Most likely word selected
  2. Higher (>1)
    1. Broader/ flatter probability distribution
    2. Less likely words become more likely to be selected
    3. This bring more randomness

Todo:

  1. [ ] Diagrams
  2. [ ] Examples
  3. [ ] More resources/ examples from the resources collected.