Can Phi 3 Medium 14B run on RTX 5080 16GB?

YES — Tight Fit

B64Good

Estimated from fit model

Phi 3 Medium 14B needs ~14.4 GB VRAM. RTX 5080 16GB has 16.0 GB. With Q4_K_M quantization, expect ~73 tok/s.

Runtime: OllamaCapacity: TightBandwidth: HighStack: BasicBottleneck: 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) — 14.4 GB, 78.5 tok/s, Tight fit

14.4 GB required16.0 GB available

90% VRAM used

Fit status

Tight fit

Decode

78.5 tok/s

TTFT

2465 ms

Safe context

24K

Memory

14.4 GB / 16.0 GB

Memory breakdown

Weights8.5 GB

KV Cache3.1 GB

Runtime1.2 GB

Headroom1.6 GB

See how fast it feels

See how fast it feelsPhi 3 Medium 14B on RTX 5080 16GB
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: 78.5 tok/s decode · 2.5s TTFT (warm) · 196 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	73.1 tok/s	1445 ms	24K
Coding	B	Tight fit	73.1 tok/s	2650 ms	24K
Agentic Coding	C	Very compromised	46.8 tok/s	6011 ms	24K
Reasoning	B	Tight fit	73.1 tok/s	3131 ms	24K
RAG	C	Very compromised	46.8 tok/s	7514 ms	24K

Quantization options

How Phi 3 Medium 14B (14B params) fits at each quantization level on RTX 5080 16GB (16.0 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	5.5 GB	Low	B60
Q3_K_S	3	6.9 GB	Low	B62
NVFP4	4

Get started

Copy-paste commands to run Phi 3 Medium 14B on your machine.

Run

ollama run phi3:medium

Upgrade options

Hardware that runs Phi 3 Medium 14B well

RTX 4000 Ada 20GBBudget pick

20 GB VRAM (+4)

Adds memory headroom for longer context windows and future model growth.35.3 tok/s decode

Adds memory headroom for longer context windows and future model growth.

~$1,250 MSRP

RTX 3090 24GBBest value

24 GB VRAM (+8)

Adds memory headroom for longer context windows and future model growth.82.5 tok/s decode

Adds memory headroom for longer context windows and future model growth.

~$1,499 MSRP

RTX 4090 24GBNVIDIA upgrade

24 GB VRAM (+8)1008 GB/s (+48)

Adds memory headroom for longer context windows and future model growth.96.4 tok/s decode

Adds memory headroom for longer context windows and future model growth.

~$1,599 MSRP

Frequently asked questions

Can RTX 5080 16GB run Phi 3 Medium 14B?

Yes, RTX 5080 16GB can run Phi 3 Medium 14B with a B grade (Tight fit). Expected decode speed: 73.1 tok/s.

How much VRAM does Phi 3 Medium 14B need?

Phi 3 Medium 14B (14B parameters) requires approximately 14.4 GB of memory with Q4_K_M quantization.

What is the best quantization for Phi 3 Medium 14B?

The recommended quantization for Phi 3 Medium 14B is Q4_K_M, which balances quality and memory efficiency.

What speed will Phi 3 Medium 14B run at on RTX 5080 16GB?

On RTX 5080 16GB, Phi 3 Medium 14B achieves approximately 73.1 tokens per second decode speed with a time-to-first-token of 2650ms using Q4_K_M quantization.

Can RTX 5080 16GB run Phi 3 Medium 14B for coding?

For coding workloads, Phi 3 Medium 14B on RTX 5080 16GB receives a B grade with 73.1 tok/s and 24K context.

What context window can Phi 3 Medium 14B use on RTX 5080 16GB?

On RTX 5080 16GB, Phi 3 Medium 14B can safely use up to 24K tokens of context. The model's official context limit is 128K, but available memory constrains the safe maximum.

See all results for RTX 5080 16GB See all hardware for Phi 3 Medium 14B

Embed this result▼

Paste this snippet into any page to show a live fit card.

<iframe src="https://willitrunai.com/embed/phi-3-medium-14b-on-rtx-5080-16gb" width="400" height="180" frameborder="0" style="border:none;border-radius:12px;overflow:hidden;" title="Will It Run AI — fit result"></iframe>

Preview: