ResearchAudio

Instrument 16 / hardware-first model fit

What LLM can I run on my GPU?

Start with the VRAM you already own. Find the largest standard model-size tier that clears a conservative weight floor, then add the exact architecture and context before downloading the checkpoint.

Find the model-size floor →

First answer / capacity floor

Turn available VRAM into a model-size ceiling.

The calculation stays in this browser. It answers the fully GPU-resident weight question first and deliberately excludes KV cache, artifact metadata, and speed.

Read the answer correctly

Tier, not recommendation.
A parameter class clearing the floor does not name the best model for your task.

Weights, not full runtime.
KV cache, activations, workspace, metadata, and fragmentation still consume memory.

Capacity, not speed.
Bandwidth, kernels, offload, and interconnect decide delivered performance.

VRAM-first planning table

What model-size floor fits 8, 12, 16, or 24 GB?

Each cell is the largest listed tier below the arithmetic ceiling with 20% runtime headroom, 90% usable memory, one GPU, and no KV cache. The small number is the ceiling before rounding down to a standard tier.

Swipe the matrix horizontally →

VRAM profileINT4INT8FP16 / BF16
8 GB8B tier12.9B ceiling3B tier6.4B ceiling3B tier3.2B ceiling
12 GB14B tier19.3B ceiling8B tier9.7B ceiling3B tier4.8B ceiling
16 GB20B tier25.8B ceiling8B tier12.9B ceiling3B tier6.4B ceiling
24 GB32B tier38.7B ceiling14B tier19.3B ceiling8B tier9.7B ceiling
32 GB32B tier51.5B ceiling20B tier25.8B ceiling8B tier12.9B ceiling
48 GB70B tier77.3B ceiling32B tier38.7B ceiling14B tier19.3B ceiling
80 GB120B tier128.8B ceiling32B tier64.4B ceiling32B tier32.2B ceiling
141 GB120B+ tier227.1B ceiling70B tier113.5B ceiling32B tier56.8B ceiling

The table uses ideal bit-width arithmetic. A real quantized artifact can be larger because tensors, metadata, embeddings, or selected layers may use different precision.

Transparent method

The result is a first gate, not a runtime promise.

Usable capacity is GPU memory × GPU count × the usable-memory percentage you select.

Weight capacity divides usable capacity by one plus the selected runtime headroom. The remaining GiB are converted into parameters at the chosen bit width.

Largest listed tier rounds down to one of the common planning sizes on this page: 3B, 7B, 8B, 13B, 14B, 20B, 27B, 32B, 70B, or 120B.

Exact deployment memory needs checkpoint size, layer count, KV heads, head dimension, context length, concurrency, and cache precision. The result button carries your selected tier and hardware into that worksheet.

Multi-GPU capacity is summed for the floor only. The model and serving runtime must support a workable tensor, pipeline, or expert-parallel layout.

Named models vary inside a tier. Use the primary-source worksheets for Qwen3 8B, 14B, and 32B, gpt-oss 20B and 120B, or the 70B worksheet.

Know the model instead? Check a model against your GPU →

Capacity references

Verify the exact card before using a preset.

The finder is vendor-neutral. These first-party hardware pages are capacity anchors for common profiles; board variants and software support can differ.

ProfileFirst-party referenceUsable at 90%
12 GBNVIDIA GeForce RTX 306010.8 GiB
24 GBNVIDIA GeForce RTX 409021.6 GiB
32 GBNVIDIA GeForce RTX 509028.8 GiB
48 GBNVIDIA RTX 6000 Ada43.2 GiB
80 GBNVIDIA A100 80GB / H100 SXM72 GiB
141 GBNVIDIA H200126.9 GiB

GPU model-fit FAQ

The questions behind “will it run?”

The fast answer is a capacity floor. The deployment answer comes from the exact artifact, context, runtime, and performance target.

What LLM can I run with 8 GB of VRAM?

At the default reserve, one 8 GB GPU clears an 8B INT4, 3B INT8, or 3B FP16 weight floor. The exact checkpoint and context can still exceed that budget.

What LLM can I run with 12 GB of VRAM?

At the default reserve, one 12 GB GPU clears a 14B INT4, 8B INT8, or 3B FP16 weight floor. Use the exact architecture calculator before downloading a model.

What LLM can I run with 24 GB of VRAM?

At the default reserve, one 24 GB GPU clears a 32B INT4, 14B INT8, or 8B FP16 weight floor. This does not guarantee speed, kernel support, or a desired context window.

Why can a model fail even when its weights fit in VRAM?

Serving also needs KV cache, activations, workspace, metadata, and fragmentation reserve. Context, batching, quantization format, supported kernels, and topology can change the boundary.

Evidence before the download

Get the next infrastructure teardown.

ResearchAudio traces architecture, measured constraints, primary sources, and the gap between “fits” and “works.”