Temperature

Temperature scales the model’s logits (unnormalized probabilities) before sampling. Lower temperature sharpens the distribution toward the most likely token; higher temperature flattens it, making rare tokens more competitive.

Quick reference
Type float
Default 0.7
Range 0.0 and above (typical 0.0 – 1.5)
Category Core sampling
Field on SamplerParameters.Temperature

What it does

Each generation step produces a vector of logits — one value per vocabulary token. The engine divides every logit by Temperature before applying softmax:

  • At Temperature = 1.0, the softmax is unchanged; the model samples from its native distribution.
  • Below 1.0, differences between logits are magnified. The top tokens become more likely; rare tokens are suppressed. At the limit Temperature = 0.0, the engine picks the single highest-logit token every step (greedy decoding).
  • Above 1.0, logits flatten. The top token’s advantage shrinks; tail tokens gain relative probability. At high temperatures, output becomes increasingly random.

Temperature runs before all downstream filters (TopP, TopK, MinP). A combination of low temperature and tight TopP produces very deterministic output; high temperature with wide filters produces creative, unpredictable output.

When to change it

Scenario Value
Fully deterministic, reproducible output 0.0 (greedy; Seed becomes irrelevant)
Precise tasks — code, structured data, classification 0.1 – 0.3
General-purpose chat (default balance) 0.7
Creative writing, brainstorming 0.8 – 1.0
Maximum variety, risk of incoherence > 1.0

Temperature trades accuracy for variety. On factual questions, high temperature increases hallucination rate. On creative tasks, low temperature produces dull, repetitive output.

Example

using Aspose.LLM;
using Aspose.LLM.Abstractions.Parameters.Presets;

var preset = new Qwen25Preset();
preset.SamplerParameters.Temperature = 0.2f; // precise, low-variety output

using var api = AsposeLLMApi.Create(preset);
string reply = await api.SendMessageAsync("List three primes under 20.");
Console.WriteLine(reply);
// Output: 2, 3, 5.

For a fully reproducible run:

preset.SamplerParameters.Temperature = 0.0f;
preset.SamplerParameters.Seed = 42; // seed is ignored when Temperature == 0

Interactions

  • TopP — applies after temperature to trim the tail.
  • TopK — hard cap on candidate count after temperature.
  • MinP — minimum relative probability after temperature.
  • Seed — irrelevant when Temperature = 0.
  • Mirostat — when active, adaptively adjusts entropy and bypasses Temperature tuning.
  • DynatempRange — dynamically varies Temperature per step based on entropy.

What’s next

TopP