Can OpenChat 7B run on RTX 4000 Ada 20GB?

YES — Runs Great

C53Usable

Estimated from fit model

OpenChat 7B needs ~9.4 GB VRAM. RTX 4000 Ada 20GB has 20.0 GB. With Q4_K_M quantization, expect ~66 tok/s.

Runtime: OllamaCapacity: RoomyBandwidth: LowStack: 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) — 9.4 GB, 70.7 tok/s, Runs well

9.4 GB required20.0 GB available

47% VRAM used

Fit status

Runs well

Decode

70.7 tok/s

TTFT

2739 ms

Safe context

Memory

9.4 GB / 20.0 GB

Memory breakdown

Weights4.3 GB

KV Cache2.0 GB

Runtime1.2 GB

Headroom2.0 GB

See how fast it feels

See how fast it feelsOpenChat 7B on RTX 4000 Ada 20GB
1st promptCold start — includes initialization
>What is local AI inference?
Local AI inference means running an AI language model directly on your own hardware — your laptop, desktop, or server — instead of sending requests to a remote cloud API.

When you run inference locally the model weights are loaded into your GPU or unified memory. Each token you generate requires reading those weights from memory, so memory bandwidth is the main bottleneck for decode speed.

Key benefits of running locally:
  - Full privacy: your prompts never leave your machine
  - No per-token cost or rate limits
  - Works offline once the model is downloaded
  - Latency depends only on your hardware
2nd promptWarm — model ready, no init overhead
>How much VRAM do I need?
It depends on the model size and quantization level. A rough rule of thumb:

  Model size     Q4 (4-bit)    Q8 (8-bit)    FP16
  7B params      ~4.3 GB       ~7.5 GB       ~14 GB
  13B params     ~7.9 GB       ~13.9 GB      ~26 GB
  70B params     ~42.7 GB      ~74.9 GB      ~140 GB

Most people use 4-bit quantization (Q4_K_M) which gives 90-95% of full quality at a fraction of the memory. A 24 GB GPU can comfortably run most 7B-13B models.
Estimated: 70.7 tok/s decode · 2.7s TTFT (warm) · 177 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	C	Runs well	70.7 tok/s	1494 ms	8K
Coding	C	Runs well	65.8 tok/s	2944 ms	8K
Agentic Coding	B	Runs well	70.7 tok/s	3983 ms	8K
Reasoning	C	Runs well	70.7 tok/s	3237 ms	8K
RAG	B	Runs well	70.7 tok/s	4979 ms	8K

Quantization options

How OpenChat 7B (7B params) fits at each quantization level on RTX 4000 Ada 20GB (20.0 GB usable).

Quant	Bits	VRAM	Quality	Fit
Q2_K	2	2.7 GB	Low	C47
Q3_K_S	3	3.4 GB	Low	C48
NVFP4	4	3.9 GB	Medium	C48
Q4_K_M	4	4.3 GB	Medium	C48
Q5_K_M	5	5.0 GB	High	C49
Q6_K	6	5.7 GB	High	C49
Q8_0	8	7.5 GB	Very High	C51
F16Best for your GPU	16	14.3 GB	Maximum	C52

Get started

Copy-paste commands to run OpenChat 7B on your machine.

Run

ollama run openchat

Frequently asked questions

Can RTX 4000 Ada 20GB run OpenChat 7B?

Yes, RTX 4000 Ada 20GB can run OpenChat 7B with a C grade (Runs well). Expected decode speed: 65.8 tok/s.

How much VRAM does OpenChat 7B need?

OpenChat 7B (7B parameters) requires approximately 9.4 GB of memory with Q4_K_M quantization.

What is the best quantization for OpenChat 7B?

The recommended quantization for OpenChat 7B is Q4_K_M, which balances quality and memory efficiency.

What speed will OpenChat 7B run at on RTX 4000 Ada 20GB?

On RTX 4000 Ada 20GB, OpenChat 7B achieves approximately 65.8 tokens per second decode speed with a time-to-first-token of 2944ms using Q4_K_M quantization.

Can RTX 4000 Ada 20GB run OpenChat 7B for coding?

For coding workloads, OpenChat 7B on RTX 4000 Ada 20GB receives a C grade with 65.8 tok/s and 8K context.

What context window can OpenChat 7B use on RTX 4000 Ada 20GB?

On RTX 4000 Ada 20GB, OpenChat 7B can safely use up to 8K tokens of context. The model's official context limit is 8K, but available memory constrains the safe maximum.

See all results for RTX 4000 Ada 20GB See all hardware for OpenChat 7B

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