Can Phi-4-reasoning-plus 14B run on RX 6750 XT 12GB?

BARELY — Tight on Memory

A71Great

Estimated from fit model

Phi-4-reasoning-plus 14B needs ~14.1 GB VRAM. RX 6750 XT 12GB has 12.0 GB. With Q4_K_M quantization, expect ~14 tok/s.

Runtime: llama.cppCapacity: OffloadBandwidth: LowStack: 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) — 14.1 GB, 14.6 tok/s, Very compromised (needs ~1.3 GB host RAM)

14.1 GB required12.0 GB available

118% VRAM needed

2.1 GB over capacity — needs offload or smaller quantization

Fit status

Very compromised (needs ~1.3 GB host RAM)

Decode

14.6 tok/s

TTFT

13242 ms

Safe context

Memory

14.1 GB / 12.0 GB

Offload

20%

Memory breakdown

Weights9.0 GB

KV Cache3.1 GB

Runtime0.9 GB

Headroom1.2 GB

See how fast it feels

See how fast it feelsPhi-4-reasoning-plus 14B on RX 6750 XT 12GB
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: 14.6 tok/s decode · 13.2s TTFT (warm) · 37 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 20% 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

Workload	Grade	Fit	Decode	TTFT	Context
Chat	S	Runs with offload (needs ~0.4 GB host RAM)	18.6 tok/s	5678 ms	5K
Coding	A	Very compromised	13.6 tok/s	14236 ms	5K
Agentic Coding	F	Too heavy	9.7 tok/s	29080 ms	5K
Reasoning	A	Very compromised (needs ~1.3 GB host RAM)	14.6 tok/s	15650 ms	5K
RAG	F	Too heavy	9.7 tok/s	36350 ms	5K

Quantization options

How Phi-4-reasoning-plus 14B (14.699999809265137B params) fits at each quantization level on RX 6750 XT 12GB (12.0 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	5.7 GB	Low	S92
Q3_K_S	3	7.2 GB	Low	S92
NVFP4Best for your GPU	4	8.2 GB	Medium	S91
Q4_K_M	4	9.0 GB	Medium	F0
Q5_K_M	5	10.6 GB	High	F0
Q6_K	6	12.1 GB	High	F0
Q8_0	8	15.7 GB	Very High	F0
F16	16	30.1 GB	Maximum	F0

Get started

Copy-paste commands to run Phi-4-reasoning-plus 14B on your machine.

Run

ollama run phi4-reasoning

Frequently asked questions

Can RX 6750 XT 12GB run Phi-4-reasoning-plus 14B?

Yes, RX 6750 XT 12GB can run Phi-4-reasoning-plus 14B with a A grade (Very compromised). Expected decode speed: 13.6 tok/s.

How much VRAM does Phi-4-reasoning-plus 14B need?

Phi-4-reasoning-plus 14B (14.699999809265137B parameters) requires approximately 14.1 GB of memory with Q4_K_M quantization.

What is the best quantization for Phi-4-reasoning-plus 14B?

The recommended quantization for Phi-4-reasoning-plus 14B is Q4_K_M, which balances quality and memory efficiency.

What speed will Phi-4-reasoning-plus 14B run at on RX 6750 XT 12GB?

On RX 6750 XT 12GB, Phi-4-reasoning-plus 14B achieves approximately 13.6 tokens per second decode speed with a time-to-first-token of 14236ms using Q4_K_M quantization.

Can RX 6750 XT 12GB run Phi-4-reasoning-plus 14B for coding?

For coding workloads, Phi-4-reasoning-plus 14B on RX 6750 XT 12GB receives a A grade with 13.6 tok/s and 5K context.

What context window can Phi-4-reasoning-plus 14B use on RX 6750 XT 12GB?

On RX 6750 XT 12GB, Phi-4-reasoning-plus 14B can safely use up to 5K tokens of context. The model's official context limit is 33K, but available memory constrains the safe maximum.

What should I upgrade first if Phi-4-reasoning-plus 14B feels slow on RX 6750 XT 12GB?

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 6750 XT 12GB See all hardware for Phi-4-reasoning-plus 14B

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