Table of Contents
Quick Verdict
Your SLA says p99 latency must stay under 400 ms. LLaMA 3 70B hits 384 ms at the 99th percentile while pushing 30.1 requests per second. Mixtral 8x7B offers a tighter p99 of 234 ms, but its throughput ceiling of 17.1 req/s means you will need nearly twice the GPU capacity to match the same total traffic volume on a dedicated GPU server.
This is a classic throughput-versus-tail-latency tradeoff. LLaMA 3 70B processes more total work per GPU, while Mixtral 8x7B keeps individual request latency tighter. The right answer depends on whether your API contract cares more about total capacity or worst-case response time.
Detailed data follows. For more pairings, visit the GPU comparisons hub.
Specs Comparison
The MoE architecture gives Mixtral a structural latency advantage — activating only 12.9B parameters per token reduces compute per request. LLaMA 3 70B’s dense design fires all 70B weights but amortises that cost efficiently under heavy batching.
| Specification | LLaMA 3 70B | Mixtral 8x7B |
|---|---|---|
| Parameters | 70B | 46.7B (12.9B active) |
| Architecture | Dense Transformer | Mixture of Experts |
| Context Length | 8K | 32K |
| VRAM (FP16) | 140 GB | 93 GB |
| VRAM (INT4) | 40 GB | 26 GB |
| Licence | Meta Community | Apache 2.0 |
See our LLaMA 3 70B VRAM requirements and Mixtral 8x7B VRAM requirements for deployment sizing.
API Throughput Benchmark
Tested on an NVIDIA RTX 3090 with vLLM, INT4 quantisation, and continuous batching under sustained concurrent load. Request payloads averaged 200 input tokens with 150 output tokens. Refer to our tokens-per-second benchmark for additional GPU data.
| Model (INT4) | Requests/sec | p50 Latency (ms) | p99 Latency (ms) | VRAM Used |
|---|---|---|---|---|
| LLaMA 3 70B | 30.1 | 108 | 384 | 40 GB |
| Mixtral 8x7B | 17.1 | 45 | 234 | 26 GB |
LLaMA 3 70B’s 76% higher request throughput makes it the better fit for APIs that must absorb traffic spikes without horizontal scaling. Mixtral’s 2.4x lower median latency is better suited for latency-sensitive endpoints where each user waits for a response. For hardware guidance, consult our best GPU for LLM inference guide.
See also: LLaMA 3 70B vs Mixtral 8x7B for Chatbot / Conversational AI for a related comparison.
See also: LLaMA 3 70B vs Qwen 72B for API Serving (Throughput) for a related comparison.
Cost Analysis
When serving APIs, total requests handled per pound of infrastructure spend is the bottom line. LLaMA 3 70B’s higher throughput means fewer GPU instances for the same traffic volume.
| Cost Factor | LLaMA 3 70B | Mixtral 8x7B |
|---|---|---|
| GPU Required (INT4) | RTX 3090 (24 GB) | RTX 3090 (24 GB) |
| VRAM Used | 40 GB | 26 GB |
| Est. Monthly Server Cost | £139 | £113 |
| Throughput Advantage | 5% faster | 12% cheaper/tok |
Run your projected API traffic through the cost-per-million-tokens calculator to see which model gives you the lowest total cost of ownership.
Recommendation
Choose LLaMA 3 70B if you are building a high-volume internal API where total throughput per GPU determines how many servers you need. Processing 76% more requests per second on the same hardware directly reduces your fleet size.
Choose Mixtral 8x7B if your API serves external users with strict per-request latency SLAs. Its 45 ms median and 234 ms p99 latency give you a comfortable margin for sub-250ms response guarantees.
Deploy behind vLLM on dedicated GPU servers with continuous batching enabled for peak efficiency.
Deploy the Winner
Run LLaMA 3 70B or Mixtral 8x7B on bare-metal GPU servers with full root access, no shared resources, and no token limits.
Browse GPU Servers
