RTX 4000 Ada 20GBコスパ重視20 GB VRAM (+4)
B
Adds memory headroom for longer context windows and future model growth.35.3 tok/sデコード
Adds memory headroom for longer context windows and future model growth.
〜$1,250 MSRP
Can Phi 3 Medium 14B run on RTX 4080 Super 16GB?
YES — Tight Fit
B64Good
Estimated from fit model
Phi 3 Medium 14B needs ~14.1 GB VRAM. RTX 4080 Super 16GB has 16.0 GB. With Q4_K_M quantization, expect ~81 tok/s.
Runtime: llama.cppCapacity: TightBandwidth: MediumStack: 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.
Select quantization to explore
Q4_K_M (Medium quality) — 14.1 GB, 80.7 tok/s, Tight fit
14.1 GB required16.0 GB available
88% VRAM used
Fit status
Tight fit
Decode
80.7 tok/s
TTFT
2398 ms
Safe context
26K
Memory
14.1 GB / 16.0 GB
Memory breakdown
Weights8.5 GB
KV Cache3.1 GB
Runtime0.9 GB
Headroom1.6 GB
See how fast it feels
See how fast it feelsPhi 3 Medium 14B on RTX 4080 Super 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: 80.7 tok/s decode · 2.4s TTFT (warm) · 202 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 | 80.7 tok/s | 1308 ms | 26K |
| Coding | B | Tight fit | 80.7 tok/s | 2398 ms | 26K |
| Agentic Coding | C | Runs with offload (needs ~0.6 GB host RAM) | 52.4 tok/s | 5378 ms | 26K |
| Reasoning | B | Tight fit | 80.7 tok/s | 2834 ms | 26K |
| RAG | C | Runs with offload (needs ~0.6 GB host RAM) | 52.4 tok/s | 6722 ms | 26K |
Quantization options
How Phi 3 Medium 14B (14B params) fits at each quantization level on RTX 4080 Super 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 | 7.8 GB | Medium | B63 |
Q4_K_M | 4 | 8.5 GB | Medium | B62 |
Q5_K_M | 5 | 10.1 GB | High | B62 |
Q6_KBest for your GPU | 6 | 11.5 GB | High | B62 |
Q8_0 | 8 | 15.0 GB | Very High | F0 |
F16 | 16 | 28.7 GB | Maximum | F0 |
Get started
Copy-paste commands to run Phi 3 Medium 14B on your machine.
Run
ollama run phi3:mediumアップグレードオプション
Phi 3 Medium 14Bを快適に動かすハードウェア
RTX 4000 Ada 20GBコスパ重視RTX 3090 24GBコスパ最良24 GB VRAM (+8)936 GB/s (+200)
B
Adds memory headroom for longer context windows and future model growth.80.8 tok/sデコード
Adds memory headroom for longer context windows and future model growth.
〜$1,499 MSRP
RTX 4090 24GBNVIDIAアップグレード24 GB VRAM (+8)1008 GB/s (+272)
B
Raises estimated decode speed by about 26%.101.3 tok/sデコード
Raises estimated decode speed by about 26%.
Adds memory headroom for longer context windows and future model growth.
〜$1,599 MSRP
Frequently asked questions
Can RTX 4080 Super 16GB run Phi 3 Medium 14B?
Yes, RTX 4080 Super 16GB can run Phi 3 Medium 14B with a B grade (Tight fit). Expected decode speed: 80.7 tok/s.
How much VRAM does Phi 3 Medium 14B need?
Phi 3 Medium 14B (14B parameters) requires approximately 14.1 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 4080 Super 16GB?
On RTX 4080 Super 16GB, Phi 3 Medium 14B achieves approximately 80.7 tokens per second decode speed with a time-to-first-token of 2398ms using Q4_K_M quantization.
Can RTX 4080 Super 16GB run Phi 3 Medium 14B for coding?
For coding workloads, Phi 3 Medium 14B on RTX 4080 Super 16GB receives a B grade with 80.7 tok/s and 26K context.
What context window can Phi 3 Medium 14B use on RTX 4080 Super 16GB?
On RTX 4080 Super 16GB, Phi 3 Medium 14B can safely use up to 26K tokens of context. The model's official context limit is 128K, but available memory constrains the safe maximum.
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