Will It Run AI

Can Cerebras-GPT 13B run on RX 7900 XT 20GB?

BARELY — Tight on Memory

B57Good
Estimated from fit model

Cerebras-GPT 13B needs ~22.3 GB VRAM. RX 7900 XT 20GB has 20.0 GB. With Q5_K_M quantization, expect ~31 tok/s.

Runtime: OllamaCapacity: OffloadBandwidth: HighStack: BasicBottleneck: Host offload
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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

Q5_K_M (High quality) 22.3 GB, 31.1 tok/s, Very compromised (needs ~1 GB host RAM)
22.3 GB required20.0 GB available
112% VRAM needed

2.3 GB over capacity — needs offload or smaller quantization

Fit status

Very compromised (needs ~1 GB host RAM)

Decode

31.1 tok/s

TTFT

6221 ms

Safe context

12K

Memory

22.3 GB / 20.0 GB

Offload

10%

Memory breakdown

Weights9.4 GB
KV Cache9.8 GB
Runtime1.2 GB
Headroom2.0 GB

See how fast it feels

See how fast it feelsCerebras-GPT 13B 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: 31.1 tok/s decode · 6.2s TTFT (warm) · 78 tok/s prefill

What limits this setup

It fits through host-memory offload, and offload is the main reason performance drops.

CPU or host-memory offload is active

About 10% of the working set spills out of accelerator memory, which usually hurts latency and sustained decode throughput.

Very little memory headroom

You can run the model, but there is not much room left for longer context, bigger batches, extra apps, or future model updates.

Best improvement path

Remove offload with more accelerator memory

Prioritize a GPU or unified-memory tier that fits the whole model natively. Removing offload usually helps more than small compute gains.

Buy headroom, not only minimum fit

A slightly larger memory tier gives you safer context growth and makes the recommendation more future-proof.

Increase host RAM if you keep offloading

This setup may need roughly {ram} GB of extra host RAM just for the offloaded portion, before OS and other tools.

Performance by workload

WorkloadGradeFitDecodeTTFTContext
ChatBTight fit52.3 tok/s2019 ms12K
CodingBVery compromised31.1 tok/s6221 ms12K
Agentic CodingFToo heavy14.5 tok/s19421 ms12K
ReasoningBVery compromised (needs ~1 GB host RAM)31.1 tok/s7352 ms12K
RAGFToo heavy14.5 tok/s24277 ms12K

Quantization options

How Cerebras-GPT 13B (13B params) fits at each quantization level on RX 7900 XT 20GB (20.0 GB usable).

QuantBitsVRAMQualityFit
Q2_K
2
5.1 GB
LowB63
Q3_K_S
3
6.4 GB
LowB64
NVFP4
4
7.3 GB
MediumB65
Q4_K_M
4
7.9 GB
MediumB65
Q5_K_M
5
9.4 GB
HighB66
Q6_K
6
10.7 GB
HighB67
Q8_0Best for your GPU
8
13.9 GB
Very HighB66
F16
16
26.7 GB
MaximumF0

Get started

Copy-paste commands to run Cerebras-GPT 13B on your machine.

Run

docker run --rm -it ghcr.io/ggerganov/llama.cpp:full \ --hf-repo "cerebras/Cerebras-GPT-13B" \ --hf-file "Cerebras-GPT-13B-Q5_K_M.gguf" \ -c 4096 -ngl 99

Opciones de mejora

Hardware que ejecuta bien Cerebras-GPT 13B

Frequently asked questions

Can RX 7900 XT 20GB run Cerebras-GPT 13B?

Yes, RX 7900 XT 20GB can run Cerebras-GPT 13B with a B grade (Very compromised). Expected decode speed: 31.1 tok/s.

How much VRAM does Cerebras-GPT 13B need?

Cerebras-GPT 13B (13B parameters) requires approximately 22.3 GB of memory with Q5_K_M quantization.

What is the best quantization for Cerebras-GPT 13B?

The recommended quantization for Cerebras-GPT 13B is Q5_K_M, which balances quality and memory efficiency.

What speed will Cerebras-GPT 13B run at on RX 7900 XT 20GB?

On RX 7900 XT 20GB, Cerebras-GPT 13B achieves approximately 31.1 tokens per second decode speed with a time-to-first-token of 6221ms using Q5_K_M quantization.

Can RX 7900 XT 20GB run Cerebras-GPT 13B for coding?

For coding workloads, Cerebras-GPT 13B on RX 7900 XT 20GB receives a B grade with 31.1 tok/s and 12K context.

What context window can Cerebras-GPT 13B use on RX 7900 XT 20GB?

On RX 7900 XT 20GB, Cerebras-GPT 13B can safely use up to 12K tokens of context. The model's official context limit is 131K, but available memory constrains the safe maximum.

What should I upgrade first if Cerebras-GPT 13B feels slow on RX 7900 XT 20GB?

Remove offload with more accelerator memory. Prioritize a GPU or unified-memory tier that fits the whole model natively. Removing offload usually helps more than small compute gains.

See all results for RX 7900 XT 20GBSee all hardware for Cerebras-GPT 13B
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