2026-10-15
ChatGPT Chat, Work, and Dot
2026-10-15 ~ 2026-10-15

The blog is generated by ChatGPT.

OpenAI’s ChatGPT has evolved beyond a conversational AI assistant. It now offers three distinct experiences: Chat, Work, and Dot, each designed for a different way of interacting with AI.

At a high level:

  • Chat: Think with AI.
  • Work: Delegate tasks to AI.
  • Dot: Pursue long-term goals with AI.

These experiences illustrate a broader evolution in AI systems: from answering questions, to executing tasks, to pursuing ongoing objectives.

1. Chat vs. Work vs. Dot — At a Glance

DimensionChatWorkDot
Primary roleAI assistantTask-execution agentPersistent agent
Main objectiveAnswer and assistComplete delegated tasksAdvance ongoing goals
Interaction styleConversationalTask-orientedGoal-oriented
ReasoningYesYesYes
Tool useSupportedSupportedSupported
Computer useNot its primary interfaceCloud/local computerDedicated cloud computer
MemoryChatGPT MemoryProject/task contextPersistent, evolving memory
Background executionThrough supported tasksYesYes
Scheduled executionSupportedSupportedSupported
Proactive behaviorLimited, task-dependentPrimarily instructed or scheduledCore design goal
Typical outcomeAnswers and insightsFinished deliverablesOngoing progress

These distinctions are conceptual rather than absolute. Chat can perform sophisticated research, Work can execute recurring tasks, and Dot can answer ordinary questions.

2026-05-07
Cache Hits in LLMs
2026-05-07 ~ 2026-10-15

The note is generated by Gemini.

Overview

In the context of Large Language Models (LLMs), a Cache Hit occurs when the inference engine identifies that specific data (tokens, KV pairs, or full responses) from a previous request is already stored in memory.


🚀 Key Types of Cache Hits

1. KV (Key-Value) Cache Hit

  • Level: Inference Engine (e.g., vLLM, TensorRT-LLM).
  • Mechanism: During the “Prefill” stage, the model stores the Key and Value tensors of the attention mechanism.
  • The Hit: Reuses stored tensors for identical prefixes.
  • Result: Drastically reduces Time to First Token (TTFT).

2. Semantic Cache Hit

  • Level: Application Layer.
  • Mechanism: Uses Vector Embeddings to compare queries.
  • The Hit: Returns a saved answer if the meaning is the same.
  • Result: Zero GPU cost and near-zero latency.

📊 Comparison Table

MetricCache HitCache Miss
ComputationLow (Retrieval)High (Full Forward Pass)
LatencyMillisecondsSeconds
CostNegligibleFull Token Usage

Tip

Maximizing your Cache Hit Ratio is the most effective way to scale LLM apps.