Would CUDA be a better path than Intel Arc A770 16GB for GPT-OSS 20B?

Often yes, if your goal is the easiest setup and the widest runtime support. Intel can offer attractive memory capacity, but CUDA still tends to win on tooling maturity, guides, kernels, and model coverage for local AI.

Can GPT-OSS 20B run on Intel Arc A770 16GB?

Q: What should I upgrade first if GPT-OSS 20B feels slow on Intel Arc A770 16GB?

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.

BARELY — Tight on Memory

A79Great

Estimated from fit model

GPT-OSS 20B needs ~17.8 GB VRAM. Intel Arc A770 16GB has 16.0 GB. With Q4_K_M quantization, expect ~29 tok/s.

Runtime: llama.cppCapacity: OffloadBandwidth: MediumStack: StandardBottleneck: Host offload

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) — 17.8 GB, 29.2 tok/s, Very compromised (needs ~1.3 GB host RAM)

17.8 GB required16.0 GB available

111% VRAM needed

1.8 GB over capacity — needs offload or smaller quantization

Fit status

Very compromised (needs ~1.3 GB host RAM)

Decode

29.2 tok/s

TTFT

6640 ms

Safe context

Memory

17.8 GB / 16.0 GB

Offload

10%

Memory breakdown

Weights12.8 GB

KV Cache2.4 GB

Runtime0.9 GB

Headroom1.6 GB

See how fast it feels

See how fast it feelsGPT-OSS 20B on Intel Arc A770 16GB
1st promptCold start — includes initialization
>Write a Python function to sort a list
Here's a Python function that sorts a list using quicksort:

def quicksort(arr):
    if len(arr) <= 1:
        return arr
    pivot = arr[len(arr) // 2]
    left   = [x for x in arr if x < pivot]
    middle = [x for x in arr if x == pivot]
    right  = [x for x in arr if x > pivot]
    return quicksort(left) + middle + quicksort(right)

# Example usage
numbers = [3, 6, 8, 10, 1, 2, 1]
print(quicksort(numbers))  # [1, 1, 2, 3, 6, 8, 10]

The algorithm picks a pivot, partitions the list into smaller, equal, and larger elements, then recursively sorts each partition and concatenates the results.
2nd promptWarm — model ready, no init overhead
>Now add type hints and a docstring
def quicksort(arr: list[int]) -> list[int]:
    """Sort a list using the quicksort algorithm.

    Args:
        arr: List of integers to sort.

    Returns:
        A new sorted list.
    """
    if len(arr) <= 1:
        return arr
    pivot = arr[len(arr) // 2]
    left   = [x for x in arr if x < pivot]
    middle = [x for x in arr if x == pivot]
    right  = [x for x in arr if x > pivot]
    return quicksort(left) + middle + quicksort(right)

Added type hints for the input and return type, plus a Google-style docstring.
Estimated: 29.2 tok/s decode · 6.6s TTFT (warm) · 73 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.

Runtime ecosystem is narrower than CUDA

Intel GPUs can look attractive on memory per dollar, but local AI tooling, kernels, and model coverage are still broader and easier on CUDA today.

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.

Prefer CUDA if you want the path of least resistance

If your goal is maximum runtime coverage, easier troubleshooting, and better support for new local AI releases, CUDA is usually still the safer upgrade path.

Buy headroom, not only minimum fit

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

Performance by workload

Workload	Grade	Fit	Decode	TTFT	Context
Chat	S	Runs with offload (needs ~0.4 GB host RAM)	33.9 tok/s	3117 ms	5K
Coding	A	Very compromised (needs ~1.3 GB host RAM)	29.2 tok/s	6640 ms	5K
Agentic Coding	F	Too heavy	22.2 tok/s	12668 ms	5K
Reasoning	A	Very compromised (needs ~1.3 GB host RAM)	29.2 tok/s	7847 ms	5K
RAG	F	Too heavy	20.7 tok/s	17022 ms

Quantization options

How GPT-OSS 20B (21B params) fits at each quantization level on Intel Arc A770 16GB (16.0 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	8.2 GB	Low	S90
Q3_K_S	3	10.3 GB	Low	S89
NVFP4Best for your GPU

Get started

Copy-paste commands to run GPT-OSS 20B on your machine.

Run

ollama run gpt-oss

Frequently asked questions

Can Intel Arc A770 16GB run GPT-OSS 20B?

Yes, Intel Arc A770 16GB can run GPT-OSS 20B with a A grade (Very compromised (needs ~1.3 GB host RAM)). Expected decode speed: 29.2 tok/s.

How much VRAM does GPT-OSS 20B need?

GPT-OSS 20B (21B parameters) requires approximately 17.8 GB of memory with Q4_K_M quantization.

What is the best quantization for GPT-OSS 20B?

The recommended quantization for GPT-OSS 20B is Q4_K_M, which balances quality and memory efficiency.

What speed will GPT-OSS 20B run at on Intel Arc A770 16GB?

On Intel Arc A770 16GB, GPT-OSS 20B achieves approximately 29.2 tokens per second decode speed with a time-to-first-token of 6640ms using Q4_K_M quantization.

Can Intel Arc A770 16GB run GPT-OSS 20B for coding?

For coding workloads, GPT-OSS 20B on Intel Arc A770 16GB receives a A grade with 29.2 tok/s and 5K context.

What context window can GPT-OSS 20B use on Intel Arc A770 16GB?

On Intel Arc A770 16GB, GPT-OSS 20B can safely use up to 5K tokens of context. The model's official context limit is 128K, but available memory constrains the safe maximum.

What should I upgrade first if GPT-OSS 20B feels slow on Intel Arc A770 16GB?

See all results for Intel Arc A770 16GB See all hardware for GPT-OSS 20B

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