Benchmarking LLM Inference: vLLM vs SGLang vs Ollama on NVIDIA Blackwell

TL;DR: We benchmarked three popular LLM inference backends—vLLM, SGLang, and Ollama—running Llama 3.1 8B on an NVIDIA RTX PRO 6000 Blackwell Max-Q GPU (96GB VRAM).

Key Takeaways:

  • The Speed King: vLLM using NVIDIA’s NVFP4 quantization hit 8,033 tokens/second, the highest throughput recorded.
  • The Efficiency Winner: When comparing identical model formats (GPTQ-INT4), SGLang beat vLLM by 17%, reaching 6,395 tokens/second.
  • The Local Option: Ollama remains the easiest to use but is significantly slower for production, topping out at 484 tokens/second (approx. 10x slower than dedicated servers).
  • Reliability: Only vLLM and SGLang maintained 100% success rates at 128 concurrent requests; Ollama broke down under this load.

The Setup

Choosing the right backend can make or break your AI application. We pushed three contenders to their limits on a beastly NVIDIA Blackwell workstation.

The Hardware

  • GPU: NVIDIA RTX PRO 6000 Blackwell Max-Q Workstation Edition (96GB VRAM)
  • CPU: Intel Core Ultra 7 (96GB RAM)
  • OS: Ubuntu Linux 24

The Contenders

  • vLLM: The production standard, tested with both NVFP4 (NVIDIA’s optimized quantization) and GPTQ-INT4.
  • SGLang: LMSYS’s structured generation engine, tested with GPTQ-INT4.
  • Ollama: The local development favorite, tested with standard llama3.1:8b (INT4).

The Results

1. Peak Throughput Comparison

The raw power difference is stark. vLLM with NVFP4 dominates, but SGLang puts up an impressive fight against vLLM’s standard GPTQ implementation.

Peak Throughput Comparison

Figure 1: Maximum throughput achieved at peak concurrency. vLLM (NVFP4) leads the pack, but SGLang outperforms vLLM when using the same GPTQ format.

2. Apples-to-Apples: SGLang vs. vLLM (GPTQ)

When we level the playing field by using the exact same GPTQ-INT4 model, the dynamic shifts. SGLang consistently outperforms vLLM across almost all concurrency levels.

Throughput Scaling

Figure 2: Throughput scaling. SGLang maintains a lead over vLLM as concurrency increases, widening the gap to 17% at 128 requests.

3. Time to First Token (TTFT)

Latency is critical for user experience. We measured TTFT at concurrency=1:

Backend Model Avg TTFT
vLLM GPTQ-INT4 10.7ms
vLLM NVFP4 13.8ms
SGLang GPTQ-INT4 14.2ms
Ollama INT4:Q4_K_M 65.0ms

Table 1: Time to first token after warmup. vLLM (GPTQ) is the fastest at 10.7ms—6x faster than Ollama.

4. Reliability Under Load

At 128 concurrent requests, vLLM and SGLang both maintained 100% success rates. Ollama broke down.


Deep Dive: Why the Differences?

vLLM’s Hardware Advantage

vLLM’s victory with NVFP4 isn’t just about software; it’s about hardware synergy. NVIDIA’s FP4 quantization packs more parameters into memory, and vLLM’s CUDA graph support on Blackwell processors allows it to extract maximum throughput.

SGLang’s “Apples-to-Apples” Efficiency

SGLang’s architecture is highly optimized. It won 6 out of 8 concurrency levels against vLLM when using the same model.

Note: We had to run SGLang with --disable-cuda-graph due to a compatibility issue with the Blackwell SM-120 architecture. We used the lmsysorg/sglang:blackwell container, and despite multiple internet sources claiming NVFP4 support, we were unable to get it working. Once SGLang patches this, we expect its performance to jump even higher.

Ollama’s Trade-off

Ollama optimizes for Developer Experience (DX), not raw server throughput. Its single-command setup is unbeatable for prototyping, but it lacks the sophisticated batching required for high-load production.

Ollama’s TTFT of 65ms is slower than vLLM/SGLang but still responsive for interactive use.


Final Verdict

If you need… The Winner is…
Maximum Production Throughput vLLM (with NVFP4)
Broad Model Support & Efficiency SGLang (with GPTQ)
Rapid Prototyping / Local Dev Ollama

Our Hybrid Approach

We have decided to use vLLM with NVFP4 for our high-throughput production inference and keep Ollama for local development and model switching.


Benchmarks conducted January 2026. Llama 3.1 8B. Request pattern: “Write a 1000 word story about {animal}” with varying animals across concurrent requests.