right signal
Pick Best inference serving

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.

Current pick
since 20 Jun 2023
1230
days as pick
Next best (challenger)
SGLang

Near-parity overall and faster on agentic/structured workloads, with major production adoption (xAI, AMD, LinkedIn, Cursor).

Why it’s the challenger
Reign history
1230days
current reign
1challenge
held off
20 JUN 2023became pick
0previous
reigns
Last reviewed: 1 Nov 2026 Reviews are continuous. This pick can change when the evidence changes.

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  • Both stacks are now well out of date: they used vLLM v0.18.0 on the legacy model runner, before Model Runner V2 became the default for all dense models in v0.25.0 (11 July 2026) and for every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.
Judged on throughput benchmarks · day-0 model support · ecosystem · operational maturity

Evidence

The sources behind this title’s record.

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.
Challenger SGLang

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.

View full changelog
Pick 20 Jun 2023 – presentvLLM Current

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 days
as pick