LLM Roofline
Llama 3 · Llama-3.1 · HF: meta-llama/Llama-3.1-8B-Instruct

Llama 3.1 8B Instruct — VRAM, KV Cache & Hardware Matrix

Serverless API Rate
$0.02 in / $0.04 out per 1M
Parameters
8.03B Dense
Attention
GQA (8 KV / 32 Q)
Layers × Hidden
32 × 4096
Max Native Context
128k tokens
MoE Experts
N/A (Dense)

Quantization Memory Footprint

Quantization BPW Weights Only Total @ 8k Ctx Total @ 32k Ctx Quality
FP16 16.00 15.26 GiB 17.57 GiB 20.57 GiB Lossless Reference
Q8_0 8.50 8.10 GiB 10.42 GiB 13.42 GiB Near-Lossless
Q6_K 6.57 6.26 GiB 8.58 GiB 11.58 GiB High Precision
Q5_K_M 5.69 5.43 GiB 7.74 GiB 10.74 GiB Balanced High
Q4_K_M 4.85 4.62 GiB 6.94 GiB 9.94 GiB Recommended 4-bit
MLX_4BIT 4.50 4.29 GiB 6.60 GiB 9.60 GiB Apple Silicon Optimized
IQ4_XS 4.25 4.05 GiB 6.36 GiB 9.36 GiB Compact 4-bit
Q3_K_M 3.91 3.73 GiB 6.04 GiB 9.04 GiB Aggressive Compression

Hardware Compatibility & Speed Leaderboard (Q4_K_M @ 32k Context)

Hardware Status Total / Limit Decode TTFT (4k) Max Safe Ctx Inspect
Cloud NVIDIA H200 SXM (141 GB) COMFORTABLE 9.9 / 140.4 GiB 435.4 tok/s 0.13s 128k Simulate →
Cloud NVIDIA H100 SXM (80 GB) COMFORTABLE 9.9 / 79.4 GiB 303.9 tok/s 0.13s 128k Simulate →
Cloud NVIDIA A100 SXM (80 GB) COMFORTABLE 9.9 / 79.4 GiB 180.6 tok/s 0.37s 128k Simulate →
NVIDIA RTX PRO 6000 Blackwell (96 GB) COMFORTABLE 9.9 / 95.0 GiB 162.6 tok/s 0.45s 128k Simulate →
NVIDIA RTX 5090 (32 GB) COMFORTABLE 9.9 / 31.0 GiB 158.7 tok/s 0.55s 128k Simulate →
NVIDIA RTX 4090 (24 GB) COMFORTABLE 9.9 / 23.0 GiB 89.3 tok/s 0.69s 128k Simulate →
NVIDIA RTX 5080 (16 GB) COMFORTABLE 9.9 / 15.0 GiB 85.0 tok/s 1.01s 73k Simulate →
NVIDIA RTX 3090 (24 GB Used) COMFORTABLE 9.9 / 23.0 GiB 80.9 tok/s 1.63s 128k Simulate →
NVIDIA RTX 5070 Ti (16 GB) COMFORTABLE 9.9 / 15.0 GiB 79.3 tok/s 1.28s 73k Simulate →
AMD Radeon RX 7900 XTX (24 GB) COMFORTABLE 9.9 / 23.0 GiB 78.8 tok/s 1.13s 128k Simulate →
Cloud NVIDIA L40S (48 GB) COMFORTABLE 9.9 / 47.4 GiB 76.5 tok/s 0.33s 128k Simulate →
Apple Mac Studio M3 Ultra (256 GB) COMFORTABLE 9.7 / 199.7 GiB 69.0 tok/s 2.12s 128k Simulate →
Apple Mac Studio M3 Ultra (512 GB) COMFORTABLE 9.7 / 399.4 GiB 69.0 tok/s 2.12s 128k Simulate →
2x NVIDIA RTX 3090 Rig (48 GB) COMFORTABLE 9.9 / 46.6 GiB 67.9 tok/s 2.00s 128k Simulate →
Apple Mac Studio M2 Ultra (192 GB) COMFORTABLE 9.7 / 149.8 GiB 67.4 tok/s 2.34s 128k Simulate →
Apple Mac Studio M4 Max (64 GB) COMFORTABLE 9.7 / 49.9 GiB 45.4 tok/s 3.21s 128k Simulate →
Apple Mac Studio M4 Max (128 GB) COMFORTABLE 9.7 / 99.8 GiB 45.4 tok/s 3.21s 128k Simulate →
NVIDIA RTX 5060 Ti (16 GB) COMFORTABLE 9.9 / 15.0 GiB 38.7 tok/s 2.42s 73k Simulate →
Apple MacBook Pro M3 Max (64 GB) COMFORTABLE 9.7 / 49.9 GiB 32.8 tok/s 4.30s 128k Simulate →
Apple MacBook Pro M3 Max (128 GB) COMFORTABLE 9.7 / 99.8 GiB 32.8 tok/s 4.30s 128k Simulate →
Apple Mac Mini M4 Pro (48 GB) COMFORTABLE 9.7 / 37.4 GiB 21.8 tok/s 6.61s 128k Simulate →
Apple Mac Mini M4 Pro (64 GB) COMFORTABLE 9.7 / 49.9 GiB 21.8 tok/s 6.61s 128k Simulate →
Ryzen AI Max+ 395 Strix Halo (128 GB) COMFORTABLE 9.7 / 96.0 GiB 20.5 tok/s 2.40s 128k Simulate →
Ryzen AI Max+ 395 Strix Halo (64 GB) COMFORTABLE 9.7 / 48.0 GiB 20.5 tok/s 2.40s 128k Simulate →
Apple Mac Mini M4 (24 GB) COMFORTABLE 9.7 / 18.0 GiB 9.3 tok/s 14.61s 110k Simulate →
Ryzen AI 9 HX 370 Mini-PC (64 GB) COMFORTABLE 9.7 / 48.0 GiB 9.1 tok/s 6.82s 128k Simulate →
NVIDIA RTX 3060 (12 GB) TIGHT 9.9 / 11.0 GiB 30.3 tok/s 4.62s 41k Simulate →
Apple Mac Mini M4 (16 GB) TIGHT 9.7 / 10.0 GiB 9.3 tok/s 14.61s 46k Simulate →

Interactive Llama 3.1 8B Instruct Simulator

8.03B 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: 128k
Memory Allocation Footprint 9.94 / 95.00 GiB usable
Weights: 4.62 GiB KV Cache: 4.00 GiB Overhead: 1.31 GiB Headroom: 85.06 GiB
Decode Speed
162.6
tok/s (batch=1)
Prefill Speed
9922
prompt tok/s
TTFT Latency
0.45s
for 4,096 tok
Active Params
8.0B
of 8.03B total
llama.cpp Server Command
llama-server -hf meta-llama/Llama-3.1-8B-Instruct:Q4_K_M -ngl 99 -fa on -c 32768 --port 8080
Context KV Cache Total VRAM Decode Status
4k 0.50 GiB 6.16 GiB 273.6 tok/s COMFORTABLE
8k 1.00 GiB 6.94 GiB 249.3 tok/s COMFORTABLE
16k 2.00 GiB 7.94 GiB 211.6 tok/s COMFORTABLE
32k 4.00 GiB 9.94 GiB 162.6 tok/s COMFORTABLE
64k 8.00 GiB 13.94 GiB 111.0 tok/s COMFORTABLE
128k 16.00 GiB 21.94 GiB 68.0 tok/s COMFORTABLE

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

USE SERVERLESS API
Own Hardware/mo
$162.07
27.0h active + power
Cloud GPU/mo
$57.51
@$1.85/hr spot/pod
Serverless API/mo
$1.60
API cheaper

Engineering FAQ — Llama 3.1 8B Instruct

How much VRAM does Llama 3.1 8B Instruct require in Q4_K_M?

Llama 3.1 8B Instruct weights occupy 4.62 GiB in Q4_K_M. Including 32k FP16 KV cache and runtime buffers, total memory is 9.94 GiB.

What is the cheapest local hardware that runs Llama 3.1 8B Instruct?

NVIDIA RTX PRO 6000 Blackwell (96 GB) (96 GB) runs Llama 3.1 8B Instruct Q4_K_M at ~162.6 tok/s decode and 0.45s TTFT.

How does Llama 3.1 8B Instruct scale KV cache at long context?

Llama 3.1 8B Instruct uses GQA with 8 KV heads across 32 layers (128 head_dim).