VRAM Reference

Qwen 2.5 72B Instruct VRAM Requirements: FP16 / INT4 / KV-Cache (2026)

Qwen 2.5 72B Instruct runs on 72.7B parameters with a 128K-token context window. Weights are deterministic param math; KV-cache uses the registry layer geometry where published, otherwise a modeled GQA estimate โ€” every figure is provenance-labeled below.

FP16 weights140 GB
INT4 weights40 GB
Context128K tokens
Single-GPU verdictFits (INT4, 49 GB)
140 GB FP16 weights
Calculated EstimateHIGH
SourceOpenGPU Radar models-registry.json (param-count weight model)
VerifiedSep 29, 2026
Value
140 GB
Methodology

weights = parametersB ร— bytes-per-parameter (FP16 = 2 B, INT4 = 0.5 B)

Refreshed daily from provider APIs and market scrapingSep 29, 2026
40 GB INT4 weights
Calculated EstimateHIGH
SourceOpenGPU Radar models-registry.json (param-count weight model)
VerifiedSep 29, 2026
Value
40 GB
Methodology

weights = parametersB ร— bytes-per-parameter (FP16 = 2 B, INT4 = 0.5 B)

Refreshed daily from provider APIs and market scrapingSep 29, 2026
128K context window
Manufacturer SpecHIGH
SourceModel vendor context-window specification
VerifiedSep 29, 2026
Value
128,000 tokens
Refreshed daily from provider APIs and market scrapingSep 29, 2026
Methodology โ†’

How much VRAM does Qwen 2.5 72B Instruct need?

Weights: 140 GB at FP16, 40 GB at INT4 (parameters ร— bytes-per-parameter: FP16 = 2 B, INT4 = 0.5 B).

Full stack at 128K: 176.7 GB FP16 / 49.3 GB INT4 โ€” including KV-cache, CUDA overhead, activations, and fragmentation headroom from the canonical VRAM engine.

Single-GPU verdict: INT4 fits 80 GB datacenter cards (A100/H100); FP16 needs 240 GB โ†’ multi-GPU.

VRAM by Precision & Context

From the canonical VRAM engine: weights + KV-cache + CUDA overhead + activations + fragmentation headroom. KV-cache uses published layer geometry where available; otherwise a modeled GQA estimate (labeled in the badge).

PrecisionContextWeightsKV-CacheTotal (est.)
FP164K145.4 GB
Calculated EstimateHIGH
SourceDeterministic VRAM Canonical Engine
VerifiedSep 26, 2026
Value
145.4 GB
Methodology

Formula: parameterCountB ร— bytesPerParam. Precision: FP16 = 2 bytes/param. (parameterCountB in billions, result in GB).

Assumptions & Parameters
  • paramCountB: 72.7
  • quantization: fp16
  • bytesPerParam: 2
Refreshed daily from provider APIs and market scrapingSep 26, 2026
0.44 GB
Calculated EstimateHIGH
SourceDeterministic VRAM Canonical Engine
VerifiedSep 26, 2026
Value
0.44 GB
Methodology

GQA KV Cache: kvBytes = 2 ร— numLayers ร— numKvHeads ร— headDim ร— contextLength ร— batchSize ร— bytesPerKvElement. GQA ratio: 4:1.

Assumptions & Parameters
  • numLayers: 28
  • numKvHeads: 8
  • headDim: 128
  • contextLength: 4096
  • batchSize: 1
  • quantization: fp16
  • gqaRatio: 4
Refreshed daily from provider APIs and market scrapingSep 26, 2026
162.2 GB
Calculated EstimateHIGH
SourceDeterministic VRAM Canonical Engine
VerifiedSep 26, 2026
Value
162.18 GB
Methodology

Total = weights + kvCache + cudaOverhead + activation + fragmentationHeadroom (10%).

Assumptions & Parameters
  • paramCountB: 72.7
  • quantization: fp16
  • contextLength: 4096
  • batchSize: 1
  • numLayers: 28
  • numKvHeads: 8
  • headDim: 128
  • gqaRatio: 4
  • architecture: qwen-2.5-72b
  • bytesPerParam: 2
  • bytesPerKvElement: 2
  • cudaOverheadGb: 1.2
  • activationGb: 0.4
  • fragmentationHeadroomPct: 10
  • isMla: false
Refreshed daily from provider APIs and market scrapingSep 26, 2026
FP1633K145.4 GB
Calculated EstimateHIGH
SourceDeterministic VRAM Canonical Engine
VerifiedSep 26, 2026
Value
145.4 GB
Methodology

Formula: parameterCountB ร— bytesPerParam. Precision: FP16 = 2 bytes/param. (parameterCountB in billions, result in GB).

Assumptions & Parameters
  • paramCountB: 72.7
  • quantization: fp16
  • bytesPerParam: 2
Refreshed daily from provider APIs and market scrapingSep 26, 2026
3.50 GB
Calculated EstimateHIGH
SourceDeterministic VRAM Canonical Engine
VerifiedSep 26, 2026
Value
3.5 GB
Methodology

GQA KV Cache: kvBytes = 2 ร— numLayers ร— numKvHeads ร— headDim ร— contextLength ร— batchSize ร— bytesPerKvElement. GQA ratio: 4:1.

Assumptions & Parameters
  • numLayers: 28
  • numKvHeads: 8
  • headDim: 128
  • contextLength: 32768
  • batchSize: 1
  • quantization: fp16
  • gqaRatio: 4
Refreshed daily from provider APIs and market scrapingSep 26, 2026
165.6 GB
Calculated EstimateHIGH
SourceDeterministic VRAM Canonical Engine
VerifiedSep 26, 2026
Value
165.55 GB
Methodology

Total = weights + kvCache + cudaOverhead + activation + fragmentationHeadroom (10%).

Assumptions & Parameters
  • paramCountB: 72.7
  • quantization: fp16
  • contextLength: 32768
  • batchSize: 1
  • numLayers: 28
  • numKvHeads: 8
  • headDim: 128
  • gqaRatio: 4
  • architecture: qwen-2.5-72b
  • bytesPerParam: 2
  • bytesPerKvElement: 2
  • cudaOverheadGb: 1.2
  • activationGb: 0.4
  • fragmentationHeadroomPct: 10
  • isMla: false
Refreshed daily from provider APIs and market scrapingSep 26, 2026
FP16128K145.4 GB
Calculated EstimateHIGH
SourceDeterministic VRAM Canonical Engine
VerifiedSep 26, 2026
Value
145.4 GB
Methodology

Formula: parameterCountB ร— bytesPerParam. Precision: FP16 = 2 bytes/param. (parameterCountB in billions, result in GB).

Assumptions & Parameters
  • paramCountB: 72.7
  • quantization: fp16
  • bytesPerParam: 2
Refreshed daily from provider APIs and market scrapingSep 26, 2026
13.67 GB
Calculated EstimateHIGH
SourceDeterministic VRAM Canonical Engine
VerifiedSep 26, 2026
Value
13.67 GB
Methodology

GQA KV Cache: kvBytes = 2 ร— numLayers ร— numKvHeads ร— headDim ร— contextLength ร— batchSize ร— bytesPerKvElement. GQA ratio: 4:1.

Assumptions & Parameters
  • numLayers: 28
  • numKvHeads: 8
  • headDim: 128
  • contextLength: 128000
  • batchSize: 1
  • quantization: fp16
  • gqaRatio: 4
Refreshed daily from provider APIs and market scrapingSep 26, 2026
176.7 GB
Calculated EstimateHIGH
SourceDeterministic VRAM Canonical Engine
VerifiedSep 26, 2026
Value
176.74 GB
Methodology

Total = weights + kvCache + cudaOverhead + activation + fragmentationHeadroom (10%).

Assumptions & Parameters
  • paramCountB: 72.7
  • quantization: fp16
  • contextLength: 128000
  • batchSize: 1
  • numLayers: 28
  • numKvHeads: 8
  • headDim: 128
  • gqaRatio: 4
  • architecture: qwen-2.5-72b
  • bytesPerParam: 2
  • bytesPerKvElement: 2
  • cudaOverheadGb: 1.2
  • activationGb: 0.4
  • fragmentationHeadroomPct: 10
  • isMla: false
Refreshed daily from provider APIs and market scrapingSep 26, 2026
INT44K36.4 GB
Calculated EstimateHIGH
SourceDeterministic VRAM Canonical Engine
VerifiedSep 26, 2026
Value
36.35 GB
Methodology

Formula: parameterCountB ร— bytesPerParam. Precision: INT4 = 0.5 bytes/param. (parameterCountB in billions, result in GB).

Assumptions & Parameters
  • paramCountB: 72.7
  • quantization: int4
  • bytesPerParam: 0.5
Refreshed daily from provider APIs and market scrapingSep 26, 2026
0.22 GB
Calculated EstimateHIGH
SourceDeterministic VRAM Canonical Engine
VerifiedSep 26, 2026
Value
0.22 GB
Methodology

GQA KV Cache: kvBytes = 2 ร— numLayers ร— numKvHeads ร— headDim ร— contextLength ร— batchSize ร— bytesPerKvElement. GQA ratio: 4:1.

Assumptions & Parameters
  • numLayers: 28
  • numKvHeads: 8
  • headDim: 128
  • contextLength: 4096
  • batchSize: 1
  • quantization: int4
  • gqaRatio: 4
Refreshed daily from provider APIs and market scrapingSep 26, 2026
42.0 GB
Calculated EstimateHIGH
SourceDeterministic VRAM Canonical Engine
VerifiedSep 26, 2026
Value
41.99 GB
Methodology

Total = weights + kvCache + cudaOverhead + activation + fragmentationHeadroom (10%).

Assumptions & Parameters
  • paramCountB: 72.7
  • quantization: int4
  • contextLength: 4096
  • batchSize: 1
  • numLayers: 28
  • numKvHeads: 8
  • headDim: 128
  • gqaRatio: 4
  • architecture: qwen-2.5-72b
  • bytesPerParam: 0.5
  • bytesPerKvElement: 1
  • cudaOverheadGb: 1.2
  • activationGb: 0.4
  • fragmentationHeadroomPct: 10
  • isMla: false
Refreshed daily from provider APIs and market scrapingSep 26, 2026
INT433K36.4 GB
Calculated EstimateHIGH
SourceDeterministic VRAM Canonical Engine
VerifiedSep 26, 2026
Value
36.35 GB
Methodology

Formula: parameterCountB ร— bytesPerParam. Precision: INT4 = 0.5 bytes/param. (parameterCountB in billions, result in GB).

Assumptions & Parameters
  • paramCountB: 72.7
  • quantization: int4
  • bytesPerParam: 0.5
Refreshed daily from provider APIs and market scrapingSep 26, 2026
1.75 GB
Calculated EstimateHIGH
SourceDeterministic VRAM Canonical Engine
VerifiedSep 26, 2026
Value
1.75 GB
Methodology

GQA KV Cache: kvBytes = 2 ร— numLayers ร— numKvHeads ร— headDim ร— contextLength ร— batchSize ร— bytesPerKvElement. GQA ratio: 4:1.

Assumptions & Parameters
  • numLayers: 28
  • numKvHeads: 8
  • headDim: 128
  • contextLength: 32768
  • batchSize: 1
  • quantization: int4
  • gqaRatio: 4
Refreshed daily from provider APIs and market scrapingSep 26, 2026
43.7 GB
Calculated EstimateHIGH
SourceDeterministic VRAM Canonical Engine
VerifiedSep 26, 2026
Value
43.67 GB
Methodology

Total = weights + kvCache + cudaOverhead + activation + fragmentationHeadroom (10%).

Assumptions & Parameters
  • paramCountB: 72.7
  • quantization: int4
  • contextLength: 32768
  • batchSize: 1
  • numLayers: 28
  • numKvHeads: 8
  • headDim: 128
  • gqaRatio: 4
  • architecture: qwen-2.5-72b
  • bytesPerParam: 0.5
  • bytesPerKvElement: 1
  • cudaOverheadGb: 1.2
  • activationGb: 0.4
  • fragmentationHeadroomPct: 10
  • isMla: false
Refreshed daily from provider APIs and market scrapingSep 26, 2026
INT4128K36.4 GB
Calculated EstimateHIGH
SourceDeterministic VRAM Canonical Engine
VerifiedSep 26, 2026
Value
36.35 GB
Methodology

Formula: parameterCountB ร— bytesPerParam. Precision: INT4 = 0.5 bytes/param. (parameterCountB in billions, result in GB).

Assumptions & Parameters
  • paramCountB: 72.7
  • quantization: int4
  • bytesPerParam: 0.5
Refreshed daily from provider APIs and market scrapingSep 26, 2026
6.84 GB
Calculated EstimateHIGH
SourceDeterministic VRAM Canonical Engine
VerifiedSep 26, 2026
Value
6.84 GB
Methodology

GQA KV Cache: kvBytes = 2 ร— numLayers ร— numKvHeads ร— headDim ร— contextLength ร— batchSize ร— bytesPerKvElement. GQA ratio: 4:1.

Assumptions & Parameters
  • numLayers: 28
  • numKvHeads: 8
  • headDim: 128
  • contextLength: 128000
  • batchSize: 1
  • quantization: int4
  • gqaRatio: 4
Refreshed daily from provider APIs and market scrapingSep 26, 2026
49.3 GB
Calculated EstimateHIGH
SourceDeterministic VRAM Canonical Engine
VerifiedSep 26, 2026
Value
49.27 GB
Methodology

Total = weights + kvCache + cudaOverhead + activation + fragmentationHeadroom (10%).

Assumptions & Parameters
  • paramCountB: 72.7
  • quantization: int4
  • contextLength: 128000
  • batchSize: 1
  • numLayers: 28
  • numKvHeads: 8
  • headDim: 128
  • gqaRatio: 4
  • architecture: qwen-2.5-72b
  • bytesPerParam: 0.5
  • bytesPerKvElement: 1
  • cudaOverheadGb: 1.2
  • activationGb: 0.4
  • fragmentationHeadroomPct: 10
  • isMla: false
Refreshed daily from provider APIs and market scrapingSep 26, 2026

Cloud GPUs That Fit Qwen 2.5 72B Instruct

Fit = full-stack total (weights + KV at 128K) โ‰ค GPU VRAM. Rates are the lowest observed on-demand rows in data/providers.json, refreshed daily.

GPUVRAMFP16 fitINT4 fitLowest on-demand
H200 SXM5141 GBOOMโœ“ fits$2.79/hr (Vast.ai)
B200 Blackwell192 GBโœ“ fitsโœ“ fits$3.99/hr (Vast.ai)
H100 SXM580 GBOOMโœ“ fits$1.89/hr (Vast.ai)
A100 80GB SXM480 GBOOMโœ“ fits$1.59/hr (Lambda Labs)
L40S48 GBOOMOOM$0.69/hr (Vast.ai)
RTX 409024 GBOOMOOM$0.34/hr (Vast.ai)

Recommended GPUs for Qwen 2.5 72B Instruct

Minimum = smallest single GPU that fits the full INT4 stack (49.3 GB). Optimal = registry recommendation, falling back to the lowest observed on-demand rate among fitting cards. Every card links to its canonical GPU page.

Workload Scenarios Using Qwen 2.5 72B Instruct

Costed workload guides that price Qwen 2.5 72B Instruct against verified cloud rates and registry VRAM math.

Next steps

Frequently Asked Questions

How much VRAM does Qwen 2.5 72B Instruct need?โ–พ
Qwen 2.5 72B Instruct needs 140 GB at FP16 (weights) and 40 GB at INT4 from the param-count weight model. Full-stack totals at 128K context are 176.7 GB (FP16) and 49.3 GB (INT4) including KV-cache, CUDA overhead, and fragmentation headroom.
Can Qwen 2.5 72B Instruct run on a single GPU?โ–พ
Yes โ€” the registry recommendation is 1x H200, and the NVIDIA H200 SXM5 (141GB HBM3e) fits the INT4 workload single-GPU. FP16 full-stack needs 176.7 GB.
What context length fits Qwen 2.5 72B Instruct?โ–พ
Registry context window is 128,000 tokens. KV-cache grows linearly with context โ€” the quantization table shows totals at 4K, 33K, 128K context for FP16 and INT4.
Weight model: parameters ร— bytes-per-parameter. KV-cache: GQA formula or modeled estimate where layer geometry is unpublished.Methodology โ†’