Layer 3 · self-hosting reality check
What it actually takes to self-host SGLang
The docs say 16 GB system. In practice you want 24 GB VRAM for useful production serving. Here is the honest version — real requirements, real monthly cost, what you will be maintaining, and the one thing that catches people out.
Usually reached from Replicate alternatives, where SGLang is one of the picks.
| RAM — documented minimum | 16 GB system |
|---|---|
| RAM — what it really needs | 24 GB VRAM for useful production serving |
| CPU | 8 vCPU alongside the GPU |
| Disk | Model weights |
| Monthly cost | $300–900/mo for a rented A100 or L40S |
| Setup time | A day including CUDA |
| How you install it | pip install plus a server command; exposes an OpenAI-compatible endpoint |
| Ongoing maintenance | Moderate. CUDA and driver versions are the recurring pain, not SGLang itself. |
| Where it stops scaling | Thousands of concurrent requests per GPU, and further than vLLM on prefix-heavy workloads. |
The thing that catches people out
Its advantage is RadixAttention, which reuses shared prompt prefixes across requests — so it is dramatically faster on agents, chat and structured extraction, and roughly ordinary on one-shot prompts that share nothing. Benchmark it on your real traffic shape. Teams adopt it expecting a universal speedup, measure independent single prompts, and conclude the published numbers were exaggerated.
When not to self-host SGLang
Your workload is one-shot prompts with no shared context. vLLM is the more mature choice there.
Every guide here carries this section. A site that only ever tells you to self-host is selling something — the useful answer is sometimes no.
Other Layer 3 self-hosting guides
Common questions
- How much RAM does SGLang actually need?
- 24 GB VRAM for useful production serving in practice. The documented minimum is 16 GB system, which is the figure at which the process starts rather than the figure at which it works under real use. 8 vCPU alongside the GPU alongside it.
- What does self-hosting SGLang cost per month?
- $300–900/mo for a rented A100 or L40S This is commodity VPS pricing and excludes your time, which is the larger cost for most people — budget for moderate. CUDA and driver versions are the recurring pain, not SGLang itself.
- How long does it take to set up SGLang?
- A day including CUDA, via pip install plus a server command; exposes an OpenAI-compatible endpoint.
- When should I NOT self-host SGLang?
- Your workload is one-shot prompts with no shared context. vLLM is the more mature choice there.
- What is the most common mistake when self-hosting SGLang?
- Its advantage is RadixAttention, which reuses shared prompt prefixes across requests — so it is dramatically faster on agents, chat and structured extraction, and roughly ordinary on one-shot prompts that share nothing. Benchmark it on your real traffic shape. Teams adopt it expecting a universal speedup, measure independent single prompts, and conclude the published numbers were exaggerated.