Reducing Latency in AI Applications Using Groq and Promptster
By Promptster Team · 2026-04-14
When you're building a real-time AI feature -- autocomplete, chatbots, inline suggestions, streaming UIs -- the difference between a 200ms response and a 3-second response is the difference between a feature users love and one they abandon. Latency isn't a secondary metric. For many applications, it's the primary metric.
Groq has made this their entire bet. Their custom LPU (Language Processing Unit) hardware is purpose-built for inference speed, and the benchmarks show it. But how fast is it really, and how do you decide when speed is worth the tradeoffs? We ran the numbers.
Why Groq Is Fast
Most AI providers run inference on GPUs -- hardware designed for parallel floating-point operations across many use cases. Groq took a different approach. Their LPU is a custom ASIC designed specifically for sequential token generation, the core operation in large language model inference.
The result is dramatically lower latency and higher throughput on supported models. Where a GPU-based provider might deliver 50-80 tokens per second, Groq regularly exceeds 500 tokens per second on smaller models.
This isn't marketing. We measured it.
Our Latency Benchmarks
We ran identical prompts across seven providers using Promptster's multi-provider comparison. Each prompt was tested 10 times to account for network variance. All tests used the same configuration: temperature 0.7, max tokens 1,000.
Short Response (Simple Q&A, ~100 tokens output)
| Provider | Model | Avg Latency | Tokens/sec |
|---|---|---|---|
| Groq | Llama 3.3 70B | 0.6s | 580 |
| Cerebras | Llama 3.1 8B | 0.4s | 620 |
| Fireworks AI | Llama 3.1 70B | 1.4s | 145 |
| Together AI | Llama 3.1 70B | 1.8s | 112 |
| OpenAI | GPT-4o mini | 1.9s | 105 |
| Gemini 2.5 Flash | 1.7s | 120 | |
| Anthropic | Claude Haiku 4.5 | 2.1s | 95 |
Medium Response (Analysis task, ~500 tokens output)
| Provider | Model | Avg Latency | Tokens/sec |
|---|---|---|---|
| Groq | Llama 3.3 70B | 1.1s | 545 |
| Cerebras | Llama 3.1 8B | 0.9s | 590 |
| Fireworks AI | Llama 3.1 70B | 3.8s | 138 |
| Together AI | Llama 3.1 70B | 4.5s | 115 |
| OpenAI | GPT-4o mini | 4.2s | 122 |
| Gemini 2.5 Flash | 3.6s | 142 | |
| Anthropic | Claude Haiku 4.5 | 4.9s | 105 |
Long Response (Detailed explanation, ~1,000 tokens output)
| Provider | Model | Avg Latency | Tokens/sec |
|---|---|---|---|
| Groq | Llama 3.3 70B | 1.9s | 530 |
| Cerebras | Llama 3.1 8B | 1.7s | 600 |
| Fireworks AI | Llama 3.1 70B | 7.2s | 140 |
| OpenAI | GPT-4o mini | 8.1s | 125 |
| Gemini 2.5 Flash | 6.8s | 148 |
The pattern is clear. Groq and Cerebras are in a different league on raw speed. As output length increases, the gap widens because tokens-per-second throughput compounds over longer responses.
The Speed-Quality-Cost Trilemma
Here's the honest part: speed comes with tradeoffs. You can optimize for any two of speed, quality, and cost -- but rarely all three simultaneously.
| Priority | Best Choice | Tradeoff |
|---|---|---|
| Speed + Quality | Groq (Llama 3.3 70B) | Higher cost than smaller models |
| Speed + Cost | Cerebras (Llama 3.1 8B) | Lower quality on complex tasks |
| Quality + Cost | OpenAI GPT-4o mini | Higher latency |
| Quality (max) | Anthropic Claude / OpenAI GPT-4o | Highest cost and latency |
For real-time applications, we've found that Groq running a 70B parameter model hits the best balance. You get sub-2-second responses even for longer outputs, with quality that holds up for production use cases like chat, summarization, and code generation.
Cerebras deserves special mention as another speed leader. Their inference speeds on smaller models rival or beat Groq's, and for use cases where an 8B model is sufficient (simple classification, extraction, routing), Cerebras is hard to beat.
When Speed Matters Most
Not every AI application needs sub-second responses. Here's where latency optimization delivers the most impact:
Real-time chat and conversational AI. Users expect near-instant responses. Anything above 2-3 seconds breaks the conversational flow and increases abandonment.
Autocomplete and inline suggestions. The value of a suggestion drops to zero if it arrives after the user has already typed past it. Target under 500ms for this use case.
Streaming UIs. Even when total response time is longer, getting the first token fast creates a perception of speed. Groq's time-to-first-token is consistently under 200ms.
Agentic workflows. When an AI agent makes multiple sequential calls (tool use, chain-of-thought, multi-step reasoning), latency compounds at each step. Cutting per-call latency from 3 seconds to 0.5 seconds turns a 30-second agent workflow into a 5-second one.
How to Benchmark Your Own Use Case
General benchmarks are useful as a starting point, but the only numbers that matter are the ones you measure with your own prompts. Provider latency varies based on prompt complexity, output length, time of day, and current load.
Here's a practical workflow using Promptster:
- Select your candidate providers. Include Groq and at least 2-3 others you're considering.
- Use your actual production prompts. Don't benchmark with toy examples -- use the real system prompt and user inputs your application handles.
- Run multiple times. A single test captures a snapshot. Run 5-10 iterations to see variance. High variance is itself a signal -- it means the provider's latency is unpredictable.
- Check quality alongside speed. Use Promptster's evaluation scoring to ensure you're not sacrificing accuracy for milliseconds. A fast wrong answer is worse than a slow right one.
- Set up scheduled tests. Provider performance changes over time. A weekly benchmark test keeps you informed if your chosen provider's latency degrades.
Putting It Into Practice
If you're building a latency-sensitive application and haven't benchmarked Groq yet, you should. The speed advantage is real and significant. But don't take our word for it -- or anyone's benchmarks.
Open Promptster, select Groq alongside your current provider, paste in a real prompt from your application, and see the response times side by side. In 30 seconds, you'll know whether the speed difference matters for your use case. That's faster than reading another benchmark article.