Mistral 7B vs Gemma 2 9B for API Serving (Throughput): GPU Benchmark

Quick Verdict

Your API SLA says p99 latency must stay below 300 ms. Mistral 7B delivers 245 ms. Gemma 2 9B hits 269 ms. Both pass — but Mistral 7B passes with 55 ms of breathing room while Gemma 2 9B scrapes through with 31 ms. Under real traffic with bursty request patterns, that margin is the difference between a clean monitoring dashboard and a pager going off at 3 AM. On a dedicated GPU server, Mistral 7B’s 42% higher requests-per-second throughput (22.5 vs 15.8) cements it as the safer choice for production API endpoints — but Gemma 2 9B’s edge is less about speed and more about what it will not say.

For broader model comparisons, see our GPU comparisons hub.

Specs Comparison

API serving under load amplifies every architectural difference. Mistral 7B’s 1.5 GB VRAM advantage at INT4 translates directly into more concurrent request slots in the KV cache, while its sliding window attention handles longer request payloads more gracefully on self-hosted infrastructure.

For detailed VRAM breakdowns, see our guides on Mistral 7B VRAM requirements and Gemma 2 9B VRAM requirements.

API Throughput Benchmark

We tested both models on an NVIDIA RTX 3090 (24 GB VRAM) using vLLM with INT4 quantisation, continuous batching, and sustained concurrent request pressure. The goal was to find the throughput ceiling and tail latency behaviour under production-like conditions. For live speed data, check our tokens-per-second benchmark.

Mistral 7B wins on every API-relevant metric: higher throughput, lower p50, and lower p99. The 42% throughput advantage means that at any given traffic level, Mistral 7B is further from its saturation point — and GPU performance degrades non-linearly as you approach saturation. This makes Mistral 7B not just faster but more predictable under variable load. Visit our best GPU for LLM inference guide for hardware-level comparisons.

See also: Mistral 7B vs Gemma 2 9B for Chatbot / Conversational AI for a related comparison.

See also: LLaMA 3 8B vs Mistral 7B for API Serving (Throughput) for a related comparison.

Cost Analysis

For API serving, the cost metric that matters is cost per request, not cost per token. Mistral 7B’s 42% throughput advantage means 42% more requests served per pound of server rental on the same dedicated GPU server.

At scale, the throughput difference can mean provisioning one server instead of two. Use our cost-per-million-tokens calculator to model the economics at your projected request volume.

Recommendation

Choose Mistral 7B for any API endpoint where throughput, predictable latency, and cost efficiency are the primary concerns. The 22.5 req/s ceiling gives you significantly more headroom for traffic growth before needing to scale horizontally. Apache 2.0 licensing removes any commercial deployment friction.

Choose Gemma 2 9B for APIs that expose model output directly to end users in regulated or brand-sensitive contexts. Gemma 2 9B’s built-in content safety reduces the risk of serving harmful or embarrassing responses, which can be worth the throughput trade-off for customer-facing applications where a single bad output has outsized reputational cost.

Serve either model behind vLLM on a dedicated GPU server with continuous batching for optimal throughput per pound spent.