Llama 3.1 8B Instruct
Llama 3.1 8B Instruct loads in 6.5 GB at Q4_K_M and is comfortable from 16 GB of memory, Macs included from the Mac Mini M6 16GB. Below: the full memory math, the cheapest card that runs it well, and the fastest machine we track.
PARAMETERS
8B
FORMAT
Q4_K_M
MIN MEMORY
12 GB
BEST FOR
Chat, Coding
Memory math
Weights (Q4_K_M)
6.5 GB
+ KV cache (16k)
~2.0 GB
Total at 16k
~8.5 GB
Comfortable from
16 GB
KV = fp16 estimate (q8_0 cache roughly halves it). "Comfortable" = weights + KV within the engine's tiered budget (~70-85% of memory).
Hardware snapshot
Go deeper
Every Llama 3.1 8B Instruct quant by real GGUF file sizeAlso tracked: Llama 3.1 8B Instruct (Q8) (Q8_0, 8 GB, min 16 GB)Also tracked: Llama 3.1 8B Instruct (Q5) (Q5_K_M, 8 GB, min 12 GB)
More Llama models
Frequently asked questions
How much memory does Llama 3.1 8B Instruct need?
6.5 GB for the Q4_K_M weights, plus ~2.0 GB of KV-cache at 16k context — about 8.5 GB total. Comfortable from 16 GB of VRAM or unified memory.
Does Llama 3.1 8B Instruct run on a Mac?
Yes — from the Mac Mini M6 16GB (~28 tok/s est.). Unified memory means the RAM budget is the only limit.
What is the cheapest GPU for Llama 3.1 8B Instruct?
The AMD Radeon RX 7900 XT is the cheapest tracked card that runs Llama 3.1 8B Instruct comfortably — ~74 tok/s est. at ~$550 used.
Cite this page
ModelFit: Llama 3.1 8B Instruct — specs, memory math and hardware verdicts. https://modelfit.io/models/llama3.1-8b/ (dataset updated 2026-09-03, CC BY 4.0).