LLM Roofline
Phi · MIT · HF: microsoft/phi-4

Phi-4 14B — VRAM, KV Cache & Hardware Matrix

Serverless API Rate
$0.07 in / $0.14 out per 1M
Parameters
14.7B Dense
Attention
GQA (10 KV / 40 Q)
Layers × Hidden
40 × 5120
Max Native Context
16k tokens
MoE Experts
N/A (Dense)

Quantization Memory Footprint

Quantization BPW Weights Only Total @ 8k Ctx Total @ 32k Ctx Quality
FP16 16.00 27.93 GiB 30.94 GiB 32.51 GiB Lossless Reference
Q8_0 8.50 14.84 GiB 17.85 GiB 19.42 GiB Near-Lossless
Q6_K 6.57 11.47 GiB 14.48 GiB 16.05 GiB High Precision
Q5_K_M 5.69 9.93 GiB 12.95 GiB 14.51 GiB Balanced High
Q4_K_M 4.85 8.47 GiB 11.48 GiB 13.04 GiB Recommended 4-bit
MLX_4BIT 4.50 7.85 GiB 10.87 GiB 12.43 GiB Apple Silicon Optimized
IQ4_XS 4.25 7.42 GiB 10.43 GiB 12.00 GiB Compact 4-bit
Q3_K_M 3.91 6.83 GiB 9.84 GiB 11.40 GiB Aggressive Compression

Hardware Compatibility & Speed Leaderboard (Q4_K_M @ 16k Context)

Hardware Status Total / Limit Decode TTFT (4k) Max Safe Ctx Inspect
Cloud NVIDIA H200 SXM (141 GB) COMFORTABLE 13.0 / 140.4 GiB 324.0 tok/s 0.21s 16k Simulate →
Cloud NVIDIA H100 SXM (80 GB) COMFORTABLE 13.0 / 79.4 GiB 226.1 tok/s 0.21s 16k Simulate →
Cloud NVIDIA A100 SXM (80 GB) COMFORTABLE 13.0 / 79.4 GiB 134.3 tok/s 0.64s 16k Simulate →
NVIDIA RTX PRO 6000 Blackwell (96 GB) COMFORTABLE 13.0 / 95.0 GiB 121.0 tok/s 0.78s 16k Simulate →
NVIDIA RTX 5090 (32 GB) COMFORTABLE 13.0 / 31.0 GiB 118.1 tok/s 0.97s 16k Simulate →
NVIDIA RTX 4090 (24 GB) COMFORTABLE 13.0 / 23.0 GiB 66.4 tok/s 1.22s 16k Simulate →
NVIDIA RTX 5080 (16 GB) COMFORTABLE 13.0 / 15.0 GiB 63.3 tok/s 1.80s 16k Simulate →
NVIDIA RTX 3090 (24 GB Used) COMFORTABLE 13.0 / 23.0 GiB 60.2 tok/s 2.93s 16k Simulate →
NVIDIA RTX 5070 Ti (16 GB) COMFORTABLE 13.0 / 15.0 GiB 59.0 tok/s 2.30s 16k Simulate →
AMD Radeon RX 7900 XTX (24 GB) COMFORTABLE 13.0 / 23.0 GiB 58.6 tok/s 2.03s 16k Simulate →
Cloud NVIDIA L40S (48 GB) COMFORTABLE 13.0 / 47.4 GiB 56.9 tok/s 0.57s 16k Simulate →
Apple Mac Studio M3 Ultra (256 GB) COMFORTABLE 12.8 / 199.7 GiB 51.3 tok/s 3.82s 16k Simulate →
Apple Mac Studio M3 Ultra (512 GB) COMFORTABLE 12.8 / 399.4 GiB 51.3 tok/s 3.82s 16k Simulate →
2x NVIDIA RTX 3090 Rig (48 GB) COMFORTABLE 13.0 / 46.6 GiB 50.5 tok/s 3.59s 16k Simulate →
Apple Mac Studio M2 Ultra (192 GB) COMFORTABLE 12.8 / 149.8 GiB 50.1 tok/s 4.21s 16k Simulate →
Apple Mac Studio M4 Max (64 GB) COMFORTABLE 12.8 / 49.9 GiB 33.8 tok/s 5.80s 16k Simulate →
Apple Mac Studio M4 Max (128 GB) COMFORTABLE 12.8 / 99.8 GiB 33.8 tok/s 5.80s 16k Simulate →
NVIDIA RTX 5060 Ti (16 GB) COMFORTABLE 13.0 / 15.0 GiB 28.8 tok/s 4.37s 16k Simulate →
Apple MacBook Pro M3 Max (64 GB) COMFORTABLE 12.8 / 49.9 GiB 24.4 tok/s 7.76s 16k Simulate →
Apple MacBook Pro M3 Max (128 GB) COMFORTABLE 12.8 / 99.8 GiB 24.4 tok/s 7.76s 16k Simulate →
Apple Mac Mini M4 Pro (48 GB) COMFORTABLE 12.8 / 37.4 GiB 16.2 tok/s 11.96s 16k Simulate →
Apple Mac Mini M4 Pro (64 GB) COMFORTABLE 12.8 / 49.9 GiB 16.2 tok/s 11.96s 16k Simulate →
Ryzen AI Max+ 395 Strix Halo (128 GB) COMFORTABLE 12.8 / 96.0 GiB 15.2 tok/s 4.32s 16k Simulate →
Ryzen AI Max+ 395 Strix Halo (64 GB) COMFORTABLE 12.8 / 48.0 GiB 15.2 tok/s 4.32s 16k Simulate →
Apple Mac Mini M4 (24 GB) COMFORTABLE 12.8 / 18.0 GiB 6.9 tok/s 26.47s 16k Simulate →
Ryzen AI 9 HX 370 Mini-PC (64 GB) COMFORTABLE 12.8 / 48.0 GiB 6.8 tok/s 12.33s 16k Simulate →
NVIDIA RTX 3060 (12 GB) OOM 13.0 / 11.0 GiB OOM — 6k Simulate →
Apple Mac Mini M4 (16 GB) OOM 12.8 / 10.0 GiB OOM — 9k Simulate →

Interactive Phi-4 14B Simulator

14.7B Dense · GQA
1792 GB/s · 250 TFLOPS
3. Weight Quantization 4.85 bpw
4. KV Cache
32,768 tok
Compute Roofline
COMFORTABLE FIT Memory-Bandwidth Bound
Max Safe Ctx: 16k
Memory Allocation Footprint 16.17 / 95.00 GiB usable
Weights: 8.47 GiB KV Cache: 6.25 GiB Overhead: 1.45 GiB Headroom: 78.83 GiB
Decode Speed
95.3
tok/s (batch=1)
Prefill Speed
5470
prompt tok/s
TTFT Latency
0.78s
for 4,096 tok
Active Params
14.7B
of 14.7B total
llama.cpp Server Command
llama-server -hf microsoft/phi-4:Q4_K_M -ngl 99 -fa on -c 32768 --port 8080
Context KV Cache Total VRAM Decode Status
4k 0.78 GiB 10.35 GiB 151.6 tok/s COMFORTABLE
8k 1.56 GiB 11.48 GiB 139.8 tok/s COMFORTABLE
16k 3.13 GiB 13.04 GiB 121.0 tok/s COMFORTABLE

Buy-vs-Cloud-vs-API Monthly TCO Break-Even

USE SERVERLESS API
Own Hardware/mo
$163.99
46.3h active + power
Cloud GPU/mo
$98.46
@$1.85/hr spot/pod
Serverless API/mo
$5.60
API cheaper

Engineering FAQ — Phi-4 14B

How much VRAM does Phi-4 14B require in Q4_K_M?

Phi-4 14B weights occupy 8.47 GiB in Q4_K_M. Including 16k FP16 KV cache and runtime buffers, total memory is 13.04 GiB.

What is the cheapest local hardware that runs Phi-4 14B?

NVIDIA RTX PRO 6000 Blackwell (96 GB) (96 GB) runs Phi-4 14B Q4_K_M at ~121.0 tok/s decode and 0.78s TTFT.

How does Phi-4 14B scale KV cache at long context?

Phi-4 14B uses GQA with 10 KV heads across 40 layers (128 head_dim).