vLLM
As of 1 Nov 2026, vLLM is the RightSignal pick for best inference serving.
Spheron's like-for-like H100 runs on Llama 3.3 70B FP8 (three-engine post published March 2026, two-engine June 2026, both refreshed 19 October 2026) put SGLang roughly 1-5% ahead of vLLM on unique-prompt traffic, a gap Spheron itself calls run-to-run variance.
Near-parity overall and faster on agentic/structured workloads, with major production adoption (xAI, AMD, LinkedIn, Cursor).
Why it’s the challengercurrent reign
held off
reigns
Why vLLM is the pick
- Spheron's like-for-like H100 runs on Llama 3.3 70B FP8 (three-engine post published March 2026, two-engine June 2026, both refreshed 19 October 2026) put SGLang roughly 1-5% ahead of vLLM on unique-prompt traffic, a gap Spheron itself calls run-to-run variance.
- Both stacks are now well out of date: they used vLLM v0.18.0 on the legacy model runner, before Model Runner V2 became the default for all dense models in v0.25.0 (11 July 2026) and for every model in v0.29.0 (9 September 2026), and SGLang v0.5.9, before breakable CUDA graphs became SGLang's default prefill path in v0.5.15.
- Pick vLLM for breadth, hardware coverage and release discipline rather than for any current throughput number.
Evidence
The sources behind this title’s record.
- vllm.ai/blog/2026-05-11-vllm-tops-artificial-analysis
- vllm.ai/blog/2026-07-16-keeping-vllm-production-quality
- pytorch.org/blog/pytorch-foundation-welcomes-vllm/
- vllm.ai/blog/2025-01-27-v1-alpha-release
- github.com/sgl-project/sglang
- vllm.ai/blog/2024-09-05-perf-update
- vllm.ai/blog/2023-06-20-vllm
Vendor numbers are treated as claims until independently reproduced — how we judge. Structured benchmark comparisons are on the roadmap.
Caveats & challengers
- Less of a two-horse race than it looks: in Spheron's three-engine H100 run on Llama 3.3 70B FP8, TensorRT-LLM led vLLM by 8-13% at 1-50 concurrent requests and about 16% at 100 once its engine was compiled, but it takes roughly 28 minutes to first request against about a minute for vLLM and SGLang.
- SGLang's edge is prefix-driven rather than general: with an 80% shared 512-token prefix it cut TTFT p50 by 37% at 50 concurrent requests, while on unique prompts the two sat within a few per cent, and enabling vLLM's --enable-prefix-caching narrowed the TTFT gap to roughly 15-18% at 10 concurrent requests, though at 50 Spheron still puts APC-on vLLM at 2,100 effective tok/s against SGLang's 2,550.
- Measure your own prefix overlap and re-run on current releases: those figures predate both vLLM's Model Runner V2 default (all dense models from v0.25.0, every model from v0.29.0, with v0.32.0 current) and SGLang's breakable CUDA graph default from v0.5.15.
Near-parity overall and faster on agentic/structured workloads, with major production adoption (xAI, AMD, LinkedIn, Cursor).
At a glance
- Title
- Best inference serving
- Licence
- Apache-2.0
- Pick since
- 20 Jun 2023
- Last reviewed
- 1 Nov 2026
- Title holders to date
- 1
- Official page
- github.com/vllm-project/vllm
Title history
Every change, on the record.
Spheron's like-for-like H100 runs on Llama 3.3 70B FP8 (three-engine post published March 2026, two-engine June 2026, both refreshed 19 October 2026) put SGLang roughly 1-5% ahead of vLLM on unique-prompt traffic, a gap Spheron itself calls run-to-run variance.
1230 daysas pick