Can Gemma 3 4B run on RX 7900 XT 20GB?

YES — Runs Great

B69Good

Estimated from fit model

Gemma 3 4B needs ~7.4 GB VRAM. RX 7900 XT 20GB has 20.0 GB. With Q4_K_M quantization, expect ~56 tok/s.

Runtime: llama.cppCapacity: RoomyBandwidth: HighStack: StandardBottleneck: Balanced

Operating mode

Choose the run profile you care about

Interactive favors responsiveness, while light API and scale-out lean harder on serving readiness. The fit stays the same, but the recommendation lens changes.

Current mode

Balanced

Balanced for general local use. Keeps the ranking neutral across personal and serving workflows.

Capabilities:

Select quantization to explore

Q4_K_M (Medium quality) — 7.4 GB, 56.0 tok/s, Runs well

7.4 GB required20.0 GB available

37% VRAM used

Fit status

Runs well

Decode

56.0 tok/s

TTFT

3457 ms

Safe context

113K

Memory

7.4 GB / 20.0 GB

Memory breakdown

Weights2.4 GB

KV Cache2.1 GB

Runtime0.9 GB

Headroom2.0 GB

See how fast it feels

See how fast it feelsGemma 3 4B on RX 7900 XT 20GB
1st promptCold start — includes initialization
>Solve: If a train travels at 60 mph for 2.5 hours, how far does it go?
Let me work through this step by step.

Given information:
  - Speed = 60 mph (miles per hour)
  - Time  = 2.5 hours

Formula: Distance = Speed x Time

Calculation:
  Distance = 60 mph x 2.5 h
           = 150 miles

The train travels 150 miles.

Double-check: at 60 mph the train covers 60 miles each hour. In half an hour it covers 30 miles. So in 2.5 hours: 60 + 60 + 30 = 150 miles. Confirmed.
2nd promptWarm — model ready, no init overhead
>What if the train stops for 20 minutes halfway?
The stop doesn't change the total distance covered while moving, but it affects total trip time.

Breakdown:
  - First half: 1.25 hours at 60 mph = 75 miles
  - Stop: 20 minutes (no distance)
  - Second half: 1.25 hours at 60 mph = 75 miles

Total distance: 150 miles (same)
Total time: 2.5 h + 0.33 h = 2.83 hours
Average speed: 150 / 2.83 = 53 mph

The distance stays the same but average speed drops to 53 mph because of the stop.
Estimated: 56.0 tok/s decode · 3.5s TTFT (warm) · 140 tok/s prefill

What limits this setup

This setup is broadly balanced for this model.

No major red flags

This recommendation has enough memory headroom and acceptable estimated speed for the selected workload.

Best improvement path

Performance by workload

Workload	Grade	Fit	Decode	TTFT	Context
Chat	B	Runs well	56.0 tok/s	1886 ms	113K
Coding	B	Runs well	56.0 tok/s	3457 ms	113K
Agentic Coding	A	Runs well	56.0 tok/s	5029 ms	113K
Reasoning	B	Runs well	56.0 tok/s	4086 ms	113K
RAG	A	Runs well	56.0 tok/s	6286 ms	113K

Quantization options

How Gemma 3 4B (4B params) fits at each quantization level on RX 7900 XT 20GB (20.0 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	1.6 GB	Low	B66
Q3_K_S	3	2.0 GB	Low	B66
NVFP4	4

Get started

Copy-paste commands to run Gemma 3 4B on your machine.

Run

ollama run gemma3:4b

Upgrade options

Hardware that runs Gemma 3 4B well

MacBook Pro M2 Max 32GBBudget pick

32 GB Unified (+12)

This setup is broadly balanced for this model.56 tok/s decode

~$1,999 MSRP

MacBook Pro M1 Max 32GBBest value

32 GB Unified (+12)

This setup is broadly balanced for this model.56 tok/s decode

~$2,499 MSRP

Frequently asked questions

Can RX 7900 XT 20GB run Gemma 3 4B?

Yes, RX 7900 XT 20GB can run Gemma 3 4B with a B grade (Runs well). Expected decode speed: 56.0 tok/s.

How much VRAM does Gemma 3 4B need?

Gemma 3 4B (4B parameters) requires approximately 7.4 GB of memory with Q4_K_M quantization.

What is the best quantization for Gemma 3 4B?

The recommended quantization for Gemma 3 4B is Q4_K_M, which balances quality and memory efficiency.

What speed will Gemma 3 4B run at on RX 7900 XT 20GB?

On RX 7900 XT 20GB, Gemma 3 4B achieves approximately 56.0 tokens per second decode speed with a time-to-first-token of 3457ms using Q4_K_M quantization.

Can RX 7900 XT 20GB run Gemma 3 4B for coding?

For coding workloads, Gemma 3 4B on RX 7900 XT 20GB receives a B grade with 56.0 tok/s and 113K context.

What context window can Gemma 3 4B use on RX 7900 XT 20GB?

On RX 7900 XT 20GB, Gemma 3 4B can safely use up to 113K tokens of context. The model's official context limit is 128K, but available memory constrains the safe maximum.

See all results for RX 7900 XT 20GB See all hardware for Gemma 3 4B

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