Only with CPU offload

Gemma 3 27B at Q4_K_M needs 17.0 GB but only 14.4 GB is addressable, so about 17% of the layers would stream from system RAM at roughly 60 GB/s. Expect around 6.9 tokens per second — usable for batch work, painful for chat.

83% on GPU 8K context Q4_K_M · 15.4 GB Gemma Terms of Use Released Mar 2025 Vision

The 2025 single-GPU generalist with vision. Its Gemma-licence terms are the reason to prefer Gemma 4 now.

What hardware do I need for Gemma 3 27B? →

Fits instead: Gemma 3 12B (8.3 GB) · Gemma 3 4B (3.3 GB)

The VRAM budget

weights 15.4 GB
Weights 15.4 GB KV cache @ 8K 1.03 GB Runtime overhead 0.6 GB Over budget 2.6 GB past 14.4 GB

Quantisation ladder

QuantWeightsTotal @ 8KMax contextTok/sQualityFit
Q8_0 27.1 GB 28.7 GB ~2.1 −0.1% ppl 14.3 GB over
Q6_K 20.9 GB 22.6 GB ~3.4 −0.4% ppl 8.2 GB over
Q5_K_M 18.1 GB 19.7 GB ~4.6 −0.8% ppl 5.3 GB over
Q4_K_M 15.4 GB 17.0 GB ~6.9 −1.9% ppl 2.6 GB over
Q3_K_M 12.5 GB 14.1 GB 11K 14 −5.4% ppl Fits
Q2_K 10.7 GB 12.3 GB 34K 16 −15% ppl Long context

Quality is the published perplexity delta against f16 weights. Max context assumes an f16 KV cache; q8_0 roughly doubles it. This model interleaves sliding-window layers (1024 tokens, 1 global in 6), which is why its cache barely grows with context.

How to run it

terminal
$ llama-server \
    -hf google/gemma-3-27b-it:Q4_K_M \
    -c 8192 -ngl 51

The engine underneath most of the others. Every knob is exposed. More on llama.cpp.

01Download is 15.4 GB. Keep it on an SSD — a first load off a spinning disk takes minutes.
02Close anything else holding VRAM. A browser with hardware acceleration can sit on 1–2 GB.
03If it falls back to CPU silently, drop the context first, then step down a quantisation.
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