What Happens Inside an LLM Server
Then I gave a few friends the URL, and a question came up that I could not answer: what does the server do when all of them press send at once?My guess was simple. These are my notes on why.Short answer: A GPU running an LLM spends most of its time reading the model from memory, not doing math. Once the weights are read for a step, making a token for ten people costs little more than making one.
- ▪Then I gave a few friends the URL, and a question came up that I could not answer: what does the server do when all of them press send at once?My guess was simple.
- ▪These are my notes on why.Short answer: A GPU running an LLM spends most of its time reading the model from memory, not doing math.
- ▪Once the weights are read for a step, making a token for ten people costs little more than making one.
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| Original publisher | Muhammad Raza |
| Canonical URL | https://muhammadraza.me/2026/what-happens-inside-an-llm-server/ |
| Publication time | Wed, 30 Sep 2026 15:39:09 +0000 |
| Retrieval time | 2026-09-30T15:52:01.974Z |
| Last seen | 2026-09-30T15:52:01.974Z |
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| Summary source text | contentText |
| Citation coverage | Summary is a WeSearch-generated derivative; primary citation is the original publisher URL. |
| Cluster | 9tJfYWH0dx5l · 1 stories |
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| Ranking reason | Story pages are not engagement-ranked. Hub feeds use recency, with optional source-diversified chronological ordering (cap consecutive stories per source). No personalized ranking. |
| Publisher visit | Yes — open original |
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| Indexing | May the item be indexed (stored, ranked, made findable)? | Allowed |
| Snippet | May a short excerpt of the publisher's text be shown? | Allowed |
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| Retrieval / RAG | May the content be exposed for third-party retrieval-augmented generation? | Not asserted |
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| Commercial reuse | May the content be reused commercially? | Not permitted |
Basis: Derived from the published RSS/Atom feed. Contact: [email protected]. Reviewed: 2026-07-24.
Opening excerpt (first ~120 words) tap to expand
aiWhat Happens Inside an LLM Server When 10 People Send a PromptWhat an LLM server does when ten people send a prompt at once: prefill, decode, the KV cache, continuous batching, PagedAttention, and more, with animations.MR Muhammad Raza September 30, 2026 · 9 min read #ai#llm#devopsI have been running models on my own machine for a while. Then I gave a few friends the URL, and a question came up that I could not answer: what does the server do when all of them press send at once?My guess was simple. One person gets about 60 tokens per second. Ten people split that, so each one gets 6. That guess is wrong. These are my notes on why.Short answer: A GPU running an LLM spends most of its time reading the model from memory, not doing math.
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