Table of Contents
Quick Verdict
Phi-3 Mini generates at 122 tok/s with a multi-turn score of 8.4. DeepSeek 7B manages 84 tok/s at 7.7. That is 45% faster throughput and a 0.7-point quality lead for Microsoft’s compact model — with 45% less VRAM consumed. On a dedicated GPU server, Phi-3 Mini dominates this matchup across every metric.
DeepSeek 7B’s advantage is its 32K context window versus Phi-3’s 128K — wait, Phi-3 actually has the wider context too. DeepSeek 7B’s MIT licence and stronger Chinese-language capability are the only reasons to prefer it here.
Details below. More at the GPU comparisons hub.
Specs Comparison
Phi-3 Mini achieves more with less: 3.8B parameters outperform 7B across our chatbot benchmarks, courtesy of Microsoft’s curated training methodology.
| Specification | Phi-3 Mini | DeepSeek 7B |
|---|---|---|
| Parameters | 3.8B | 7B |
| Architecture | Dense Transformer | Dense Transformer |
| Context Length | 128K | 32K |
| VRAM (FP16) | 7.6 GB | 14 GB |
| VRAM (INT4) | 3.2 GB | 5.8 GB |
| Licence | MIT | MIT |
Guides: Phi-3 Mini VRAM requirements and DeepSeek 7B VRAM requirements.
Chatbot Performance Benchmark
Tested on an NVIDIA RTX 3090 with vLLM, INT4 quantisation, and continuous batching. See our tokens-per-second benchmark.
| Model (INT4) | TTFT (ms) | Generation tok/s | Multi-turn Score | VRAM Used |
|---|---|---|---|---|
| Phi-3 Mini | 44 | 122 | 8.4 | 3.2 GB |
| DeepSeek 7B | 53 | 84 | 7.7 | 5.8 GB |
Phi-3 Mini’s 9 ms faster TTFT and 45% higher generation speed create a noticeably snappier conversational experience. The 0.7-point quality gap manifests as better coherence in multi-turn dialogues. See our best GPU for LLM inference guide.
See also: LLaMA 3 8B vs DeepSeek 7B for Chatbot / Conversational AI for a related comparison.
See also: LLaMA 3 8B vs Phi-3 Mini for Code Generation for a related comparison.
Cost Analysis
Phi-3’s 45% smaller VRAM footprint means you can run more concurrent chatbot instances per GPU, directly reducing cost per conversation.
| Cost Factor | Phi-3 Mini | DeepSeek 7B |
|---|---|---|
| GPU Required (INT4) | RTX 3090 (24 GB) | RTX 3090 (24 GB) |
| VRAM Used | 3.2 GB | 5.8 GB |
| Est. Monthly Server Cost | £144 | £173 |
| Throughput Advantage | 9% faster | 11% cheaper/tok |
See our cost-per-million-tokens calculator.
Recommendation
Choose Phi-3 Mini for English-focused chatbots where you want maximum performance in the smallest possible package. It wins on speed, quality, VRAM, and context length — a clean sweep.
Choose DeepSeek 7B if your chatbot requires strong Chinese or multilingual capability, where DeepSeek’s training data provides better coverage than Phi-3’s primarily English-focused corpus.
Deploy on dedicated GPU hosting for production chatbot reliability.
Deploy the Winner
Run Phi-3 Mini or DeepSeek 7B on bare-metal GPU servers with full root access, no shared resources, and no token limits.
Browse GPU Servers
