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Generative AI

Assessing an AI service means linking a task to computation, then to equipment, electricity and environmental impacts. This page covers training, fine-tuning, text and media generation, image and video analysis, and audio transcription. The method connects server processing to the complete service life cycle.

Define the service​

A request is not a sufficient unit without its function: context length, output volume, expected quality, latency and number of attempts. One million tokens, one minute of video and a training run are different units.

The boundary distinguishes server processing, reserved infrastructure, the application service, model development and the hardware life cycle. Each level comprises resources and activities to inventory.

The SCI-AI specification1 distinguishes provider and consumer responsibilities. It helps define the boundary; each study retains an explicit scope.

From service to impacts​

Representative measurements form the reference for duration and energy when available. The operations model makes assumptions explicit when those data are missing. A complete API footprint already includes its components; adding them would create a double count.

Tokens, parameters and operations​

A token is a tokenizer unit, not a word. Tokenization depends on model, language and content. Counts come from the API or tokenizer; a constant words-to-tokens conversion remains an approximation.

Parameters are model weights. Most participate in dense-model computation; a Mixture of Experts (MoE) activates only a subset per token. Computation uses active parameters, while memory must accommodate stored weights and required states. FLOP is an operation count; FLOP/s is throughput. These units are not interchangeable.

SymbolDefinitionUnit
PP, PpP_pActive parameters of the generative and prompt modelsCount
TT, TinT_{in}, ToutT_{out}Processed, input and output tokensTokens
QQ, mmTheoretical GPU throughput and MFUFLOP/s; fraction
nn, HHGPUs per server; hardware lifetimeCount; hours
WgW_g, WsW_sOne GPU's power; server power excluding GPUsWatts
MgM_g, MsM_sOne GPU's manufacture; server manufacture excluding GPUskg CO₂e

Text, training and fine-tuning​

Transformer compute approximations mainly represent operations proportional to parameter count (Hoffmann et al.2).

ProcessApproximate workloadConvention
TrainingF=6PTF=6PTForward pass and backpropagation
Fine-tuningF=6PTF=6PTFull-training proxy; no assumed LoRA saving
Prompt processingFp=2PTinF_p=2PT_{in}Before prefix reuse
Text generationFg=2PToutF_g=2PT_{out}Generation with cached context states

TT counts all presentations of the data: a 10-billion-token corpus processed three times means 30 billion processed tokens. A further multiplication by batch and steps would duplicate their contribution if already included.

In these formulas, PP means active parameters per token, including shared MoE layers. When routing varies, the count uses the average parameters involved across processed tokens. For example, Mixtral 8×7B uses about 13 billion parameters per token out of 47 billion total; using 47 billion in 2PT2PT would overestimate this compute component.3

A frozen parameter is not an inactive parameter. Its value stays fixed during training, but it still participates in the forward pass. Backpropagation through its layer remains necessary when upstream parameters are trained. LoRA reduces updated weights and their optimizer states; compute savings depend on the operations retained.4

The 6PT6PT proxy remains a full-training estimate here, without an automatic discount for frozen layers. Fine-tuning-specific computation distinguishes the forward pass, gradient propagation and weight updates. Multiplying PP by the trainable fraction alone is insufficient.

These approximations do not detail attention, routing, communication or memory movement. Precision, quantization and batch size affect performance without automatically reducing parameter count.

Generate images, video or audio​

Prompt and media are calculated separately. Some profiles use a separate prompt encoder: Fp=2PpTinF_p=2P_pT_{in}. These generation paths start from a text prompt. Media supplied as input follows the analysis paths in the next section.

The following expressions give total workload FF, including the prompt. For DiT/hybrid profiles, A(x)=2Px+4Lx2dA(x)=2Px+4Lx^2d represents one step over xx positions: parameter-proportional computation and attention. LL is the layer count and dd the hidden width.5

Generated outputApproximate workloadVolume parameters
Images, DiT/hybridF=Fp+kS A(N)F=F_p+kS\,A(N)kk images, SS steps, NN positions per image
Video, DiT/hybridF=Fp+S A(Nv)F=F_p+S\,A(N_v)NvN_v spatiotemporal positions
Autoregressive audioF=Fp+2PNaqF=F_p+2PN_aqNaN_a audio positions, qq codebooks
Diffusion audioF=Fp+S A(Na)F=F_p+S\,A(N_a)NaN_a audio positions, SS steps

Image and video profile formulas​

For an image of width ww and height hh, profiles assume spatial downsampling by 8 followed by patches of side pp in latent space:

N=⌈⌊w/8⌋p⌉⌈⌊h/8⌋p⌉N=\left\lceil\frac{\lfloor w/8\rfloor}{p}\right\rceil \left\lceil\frac{\lfloor h/8\rfloor}{p}\right\rceil

For video, kk is the frame count. A profile can pad it to a multiple of bb before temporal compression by factor cc:

k′=⌈k/b⌉b,Nv=(⌊k′−1c⌋+1)Nk'=\lceil k/b\rceil b,\qquad N_v=\left(\left\lfloor\frac{k'-1}{c}\right\rfloor+1\right)N

A 5-second video at 24 frames/s therefore means 120 frames before compression. A 1,024 × 1,024 image has four times as many spatial positions as a 512 × 512 image; the attention term grows faster.

U-Net profiles instead use F=Fp+kS 2P⌊w/8⌋⌊h/8⌋F=F_p+kS\,2P\lfloor w/8\rfloor\lfloor h/8\rfloor; for video, kk is replaced by k′k'. This approximation does not detail convolutions or VAE decoding.

Audio profile formulas​

For duration tt in seconds and sample rate fsf_s, positions total Na=⌈tfs/ct⌉N_a=\lceil t f_s/c_t\rceil, where ctc_t is the profile's temporal reduction. The qq codebooks are sets of codes used to represent audio.

These proxies need calibration by architecture and engine. The qq multiplier alone does not describe parallel or sequential codebook execution. MusicGen and Stable Audio Open document architectures without validating these energy estimates. Codecs, decoding and output processing still need to be inventoried.6

Analyze input media​

Analysis adds media encoding, processing its representation with the instructions, and response generation. An API-billed “image token” is not a universal energy factor.

InputApproximate workloadProfile and boundary
Images, scanned pagesF=Fenc+2Plang(Tin,eff+Tm+Tout)F=F_{enc}+2P_{lang}(T_{in,eff}+T_m+T_{out})Qwen2.5-VL 7B; TmT_m visual positions
VideoSame formula, with Tm=UN/4T_m=UN/4Qwen2.5-VL 7B; UU frame pairs, excluding audio
AudioF=C(Fconv+Fenc,chunk+Fdec,chunk)F=C(F_{conv}+F_{enc,chunk}+F_{dec,chunk})Whisper base; C=⌈t/30⌉C=\lceil t/30\rceil chunks of 30 s

Visual and audio input calculations​

Images and video. Qwen2.5-VL uses 14-pixel patches, 2 × 2 spatial merging and temporal grouping in pairs. Processed dimensions w,hw,h are rounded up to multiples of 28. A still image is repeated to form a pair.7

N=(w/14)(h/14),Tm=UN/4N=(w/14)(h/14),\qquad T_m=UN/4

UU counts independent images or video frame pairs, with U=⌈⌈tf⌉/2⌉U=\lceil\lceil t f\rceil/2\rceil for duration tt and ff analyzed frames per second. FencF_{enc} adds patch projection, linear projections, attention and merging. The encoder has 32 layers, four with global attention; the others use windows.8

The language core has about 7.61 billion parameters (PlangP_{lang}), separately from the encoder. Tin,effT_{in,eff} is the instruction after any prefix reuse. Caching removes neither encoding nor media positions. Long-context language attention, normalization and nonlinear operations are not detailed.

Context includes the full instruction, media positions and response. Beyond the 128,000 positions assumed for this profile, another segmentation is needed. Resolution describes an already resized image; it does not automatically reproduce actual preprocessing.

Audio. Whisper base has six encoder and six decoder layers of width d=512d=512. Audio is resampled to 16 kHz and split into 30 s windows, padded as needed. Each chunk has N=1 500N=1\,500 positions after convolution.910

For C>0C>0, the ToutT_{out} transcript tokens are distributed as u=Tout/Cu=T_{out}/C tokens per chunk. With Le=Ld=6L_e=L_d=6 layers and vocabulary V=51 865V=51\,865:

Fconv=2(3000)(80)d(3)+2Nd2(3)Fenc,chunk=Le(24Nd2+4N2d)Fdec,chunk=Ld(4Nd2+28ud2+2du(u+1)+4Nud)+2udV\begin{aligned} F_{conv}&=2(3000)(80)d(3)+2Nd^2(3)\\ F_{enc,chunk}&=L_e(24Nd^2+4N^2d)\\ F_{dec,chunk}&=L_d\bigl(4Nd^2+28ud^2\\ &\quad+2du(u+1)+4Nud\bigr)+2udV \end{aligned}

The decoder includes cross-attention projections, generation with KV caching and vocabulary projection. For u=0u=0, its proxy cost is zero; zero audio duration also gives zero chunks. One multiply-add counts as two FLOP.

The limit is 448 tokens per chunk. Beam search, retries, silence detection and adaptive segmentation are excluded. Thus, 10 and 30 seconds fill the same chunk in this scenario; these steps depend on the engine and are not energy measurements. MFU and power still need calibration.

Analysing a video with sound
30-second video
30 frames1 frame/s · 448 × 448 pxVisual encoding15 temporal pairs3,840 visual positions
Audio trackIf relevant to the taskTranscriptionSeparate processingTranscribed text
Model + instructions → summaryResponse counted only once

Illustrative composite workflow. Visual values follow this page’s Qwen2.5-VL profile; its video profile excludes audio. A native audio-video model requires a dedicated profile.

Combine modalities without double counting​

Summarizing video with sound involves the visual track, transcription and, where needed, transcript processing. An already included response remains counted once. A scanned PDF uses the image path for its pages; a PDF with extracted text can use the text path.

Two ways to combine media

Separate stages: dubbing example

  1. Source audioTranscription
  2. TextTranslation
  3. Translated audioSpeech generation
Each processing stage is counted once.

Joint model: image-guided video example

  1. Image + instructionConditioning
  2. Joint modelConditioned generation
  3. Generated videoOutput

In a joint architecture, input media can condition every generation step. Its cost cannot be inferred by adding two independent profiles.

Image editing and native audiovisual models also need architecture-specific profiles. Joint architectures require deployment measurements or a dedicated profile. Decoding, transfers, storage and application processing complete the boundary where material.

GPU time and server time​

DGPU,h=FQm 3600,Dserver,h=DGPU,hnD_{GPU,h}=\frac{F}{Qm\,3600},\qquad D_{server,h}=\frac{D_{GPU,h}}{n}

MFU is the fraction of theoretical throughput used for modeled work. The default 0.4 is an assumption, not a hardware constant. Throughput must match precision and compute units: the H10011 value of 989 TFLOP/s refers here to dense FP16/BF16, not FP32.

At unchanged MFU, dividing by nn assumes speedup proportional to the GPU count. Recalibrate MFU when the configuration changes. Modeled duration, prompt latency and throughput are not service benchmarks. Memory feasibility is assessed separately: weights, KV cache, activations and optimizer states must fit the available resources.

MFU: why actual throughput falls below the peak​

MFU (Model FLOPs Utilization) is the ratio of useful model computation throughput to the accelerators’ theoretical throughput. An MFU of 0.4 means that 40% of that theoretical throughput contributes to the counted work. It does not mean that the GPU is idle 60% of the time or draws 40% of its power. The definition in PaLM, section 4.112 excludes additional activation recomputation operations.

Throughput constraintWhy it matters
Memory accessWeights, activations and KV cache must move between GPU memory and compute units. Memory bandwidth can limit throughput before the compute units are saturated.
Buses and interconnectsPCIe, NVLink and the network between servers carry data. Exchanges and synchronization between GPUs can leave some units waiting.
Parallelism and batch sizeSmall batches underuse the GPU. Spreading a model across more GPUs adds communication; a pipeline can also have idle gaps between stages.
Dependencies and executionIn autoregressive generation, each new token depends on earlier ones. Matrix dimensions, supporting operations and software scheduling also affect throughput.

NVIDIA’s guides to GPU performance13 and distributed parallelism14 describe these constraints. Transfers can partially overlap computation: their durations should not simply be added together.

In the operation-count model, MFU is an overall coefficient; buses and communication are not simulated separately. It determines duration through D=F/(nQm)D=F/(nQm). With the same workload and hardware, changing 0.4 to 0.2 doubles estimated duration, and therefore energy and manufacture allocated to active time in this constant-power model. This is not a general law of electricity consumption.

From theoretical to useful throughput
100theoretical TFLOP/s
MFU = 0.4
40useful TFLOP/s
Memory · GPU communication · dependencies
400 TFLOP ÷ 40 TFLOP/s = 10 seconds

Teaching example. MFU describes compute throughput, not the share of electrical power consumed.

Choosing and calibrating MFU​

The default 0.4 is an initial assumption, not a universal average. For inference, it acts as an effective coefficient to calibrate: prompt processing and generation face different constraints. A training MFU is therefore not directly transferable to an isolated request.15

For nn identical GPUs, a measured processing duration tt in seconds gives m=F/(nQt)m=F/(nQt). This estimate depends on the operation-count convention for FF, the numerical precision of QQ, batch size, engine and hardware. A value above 1 indicates inconsistent measurement, boundaries or conventions.

Measurement on the complete configuration produces an MFU that already includes parallelization losses; a second penalty would count them twice. Periods without requests and queueing time remain separate from this calibration. Measured duration and energy do not require an additional MFU adjustment.

A parametric MFU calculation is planned for an upcoming methodological revision, linking these constraints to hardware and workload. It still needs calibration and validation against measurements; it is not yet part of the calculation rules.

Electricity and manufacture​

Esite,kWh=DGPU,hWg+Ws/n1000 PUEE_{site,kWh}=D_{GPU,h}\frac{W_g+W_s/n}{1000}\,PUE Iuse=Esite,kWh felectricity,Imanufacture=DGPU,hH(Mg+Ms/n)I_{use}=E_{site,kWh}\,f_{electricity},\qquad I_{manufacture}=\frac{D_{GPU,h}}{H}(M_g+M_s/n)

The server excluding GPUs includes CPU, RAM, storage and enclosure. PUE multiplies IT electricity, not manufacture. Energy measured across the whole site already includes this contribution. Nominal profile powers do not replace average server-level measurements.

HH is hardware lifetime in hours: H=years×365.25×24H=years\times365.25\times24.

The calculation above allocates manufacture by processing time. A server reserved for a service remains allocated to it during periods without requests. Faster processing does not remove this manufacturing share; it still needs to be distributed among the services reserving the hardware.

Two different cache mechanisms​

1. KV cache

Within a single generation

Keeps attention keys and values for tokens already processed so they can be reused in subsequent steps.

Avoids recomputing previous token states. Its use is assumed in the generation calculation.

2. Prefix cache

Across requests

Reuses states for a shared prompt prefix, such as the same instructions or document.

Reduces shared-prefix processing without reducing response generation.

Effect of prefix caching​

The reused prefix fraction rr reduces prompt computation:

Fp,effective=Fp[(1−r)+αr],r=TcachedTinF_{p,effective}=F_p\left[(1-r)+\alpha r\right],\qquad r=\frac{T_{cached}}{T_{in}}

Residual coefficient α=0.1\alpha=0.1 is an assumption about retained work. The correction precedes duration, energy and active-time manufacturing allocation. Generation work is unchanged. Actual reuse requires measurement; memory, eviction, retention and cache synchronization can add costs.

Example: 405.87 billion parameters, 100 input tokens and 400 output tokens give 405.87×1012405.87\times10^{12} FLOP. With full prefix reuse and 10% residual work, workload becomes 332.8134×1012332.8134\times10^{12} FLOP. This is a proxy result, not measured savings.

Complete the life cycle​

Processing during the study period is distinguished from the training share allocated to the service.16 It is a separate contribution from inference.

Training allocation across uses relies on a documented denominator: actual service volume over a period, reserved capacity, or future-use scenarios. Allocated training intensity is Itrain/VserviceI_{train}/V_{service}. When that volume is unknown, scenarios make the uncertainty visible. A forecast remains distinct from a measurement.

For a RAG or agent application, the inventory covers each stage: indexing, embeddings, retrieval, model calls, tools, storage and retries. Impacts are summed for a completed task, without duplicate server contributions from already assessed services. Web, Cloud and Hosting cover complementary contributions.

Direct site water requires a defined WUE and compatible IT energy. Water associated with electricity requires a different factor. Metals, resources and toxicity need characterized inventories; they cannot be inferred from carbon through a constant ratio.

Life-cycle contributions of a RAG task
Model trainingDocument indexing
A share allocated to the task
  1. Question
  2. Retrieval
  3. AI model
  4. Completed task
HardwareElectricityNetworkStorage

Simplified RAG example. Tools and retries extend the sequence when needed.

Measurement, uncertainty and method choice​

ApproachRequired dataAppropriate use
Deployment measurementDuration, server power, load, idle capacity, allocationCalibrate an actual service; disclose measurement boundaries
This page's FLOP proxyArchitecture, volumes, hardware, MFU and powersExplore dependencies and make assumptions explicit
EcoLogits17Model, provider and activities covered by its methodsCall assessment using its corpus, within the supported modality and version

EcoLogits now documents LLM inference and video-generation methods. Boundaries and models differ: ranking results without aligning task, hardware, idle capacity, caching and electricity mix does not establish method accuracy.

Calibration relies on measurements across prompt and output sizes, batches and load levels. Separate analysis of duration and energy supports adjustments to MFU or powers. An independent measurement set provides an error check. An interval produced by varying assumptions is a sensitivity analysis, not a statistical confidence interval.

Recent work and what it supports​

More than Carbon (2025)18 examines the A100 life cycle across multiple impact categories. AI hardware life-cycle emissions (2025)19 addresses hardware production and use. They support separating phases and indicators; they do not validate every hardware profile in this methodology.

The Moshi research study (2026 preprint)20 includes experiments, failed runs and development stages. For video, Video Killed the Energy Budget (2025)21 studies latency and power regimes of open models. These findings motivate explicit boundaries and deployment-specific calibration, not a universal factor per token or media second.

These choices rely on boundaries, allocation, data quality and double counting.

Relating corpus studies to D4B calculations​

The ADEME GPU report allocates impacts over the card's useful activity hours. The D4B example above divides manufacturing impacts by calendar lifetime hours, then allocates them to computation time. These denominators differ when hardware is idle; a per-GPU-hour factor is not interchangeable without its allocation rule.22

The report covers the assessed hardware. Its exclusions, including networks, user devices and buildings, do not become exclusions for a complete AI service. The factor's boundary must be known before adding the remaining server or electricity.22

How Hungry is AI? estimates inference energy from API performance, inferred hardware configurations, power assumptions and batch size. Its results are not direct electricity measurements of the APIs. The model excludes idle power from unused GPUs in partially loaded nodes: this limitation remains explicit when relating it to reserved infrastructure.23

Comparison with published measurements exposes a concrete limitation: at equal total token count, the fixed-MFU proxy does not reproduce the observed difference between long prompts and long responses. Batch size also changes energy per request. Calibration must distinguish these conditions; no universal correction is inferred.24

Assumptions and limitations​

The operation-count model provides a server-processing estimate, based on operation counts and hardware profiles. A source describing model architecture does not by itself validate energy use or environmental impacts.

Working assumptions​

ItemInitial assumptionWhat to adapt
Computation and parallelismMFU 0.4; theoretical throughput at the GPU profile’s precisionDuration measured for the actual model, engine, batch and hardware
ElectricityPUE 1.2; United States factor initially selected, 2025 snapshotSpecified location and period; national factors do not represent a site hour by hour
HardwareProfile-based power and manufacture; five-year lifetimeMeasurements and a documented inventory take precedence over proxies
AllocationManufacture allocated by active time; other components shared per GPUReserved idle capacity and server-sharing rules included
ModelReferenced or explicitly assumed architecture and parametersSpecified version, precision, quantization and supported modalities
CacheKV cache assumed; 0% prefix reuse initially, retaining 10% of computation when reusedMeasured reuse; retention, eviction and transfers are not modeled in detail

Values used for a study are documented with their sources and may differ from these initial assumptions. For visual inputs, prefix caching reduces text only; this correction does not apply to the audio transcription profile.

Known limitations​

  • Partial boundary. Devices, external networks, application storage, RAG, idle capacity and buildings require additional inventory. Training is not automatically allocated to inference requests.
  • Hardware feasibility unchecked. Weights, activations and caches may exceed available memory. Input-profile context checks do not validate memory capacity. Available profiles do not represent TPUs, FPGAs or other accelerators.
  • Simplified performance. Formulas do not detail every attention, routing, memory or communication cost. Power is constant in the calculation; the same MFU does not guarantee equal efficiency for another workload.
  • Modality coverage. Input video excludes its audio track; Whisper uses padded 30 s chunks. Generation profiles are exploratory. Image editing and joint multimodal models require dedicated profiles.
  • Uncertain data. Closed-model specifications, manufacturing factors and actual activity may be poorly known. A billed unit or cached token is not a physical impact measurement.

Interpret and substantiate the result​

Displayed electricity and climate impacts are a boundary-specific subtotal, not a complete LCA, guaranteed latency or universal per-request factor. Water, resources and toxicity require their own data; they cannot be inferred from carbon.

Reusing a result requires a documented task, model version, hardware, location, period and exclusions. Validation relies on measurements of duration and energy; varying assumptions describes sensitivity, not a confidence interval. Complete the life cycle and Measurement, uncertainty and method choice explain the next steps.

Worked example: Llama 3.1 405B​

This historical example makes the arithmetic reproducible. It uses a rounded 405 billion parameters, 15 trillion tokens and an electricity factor of 0.420 kg CO₂e/kWh. The simulator uses its profile parameters and selected versioned national factor, so values may differ.

Configuration, training and inference calculations​

ComponentPowerManufacture
8 H100 GPUs8 × 700 W8 × 250 kg CO₂e
2 CPUs2 × 350 W2 × 113 kg CO₂e
RAM, 2,000 GB2,000 × 0.392 W2,000 × 1.3 kg CO₂e
SSD, 30,000 GB30,000 × 0.0012 W30,000 × 0.16 kg CO₂e
EnclosureNot separately specified250 kg CO₂e
Total excluding GPUs1,520 W7,876 kg CO₂e

These manufacturing factors are historical assumptions, not a certified DGX LCA. With MFU 0.4, PUE 1.2 and five-year lifetime:

StepCalculationRounded result
Training workload6×405×109×15×10126\times405\times10^9\times15\times10^{12}3.645×10253.645\times10^{25} FLOP
Cumulative GPU timeF/(989×1012×0.4×3600)F/(989\times10^{12}\times0.4\times3600)25.59 million GPU·h
Site electricityDGPU,h×(0.700+1.520/8)×1.2D_{GPU,h}\times(0.700+1.520/8)\times1.227.33 million kWh
UseE×0.420E\times0.42011,480 t CO₂e
Allocated manufactureDGPU,h(250+7876/8)/(5×365.25×24)D_{GPU,h}(250+7876/8)/(5\times365.25\times24)721 t CO₂e

The Meta model card25 reports 30.84 million GPU hours for 405B. The roughly 17% time discrepancy does not validate the model: precision, utilization, ancillary operations and boundaries need alignment.

For one million generated tokens, excluding the prompt, the same scenario gives 0.569 GPU·h, 255 g CO₂e of use and 16 g of manufacture, totaling 271 g. With 400 input and 400 output tokens and no prefix caching, the proxy gives about 0.217 g CO₂e. These are not universal per-request factors.

Interactive example​

The interactive example applies the operation-count model described above to server processing. Its coverage remains partial: it is neither a complete service LCA nor a complete SCI-AI implementation.

BoundaryInventory to collectSimulator coverage
Server processingAccelerators, CPU, RAM, storage, duration, energy and allocated manufactureIncluded through simplified profiles
Reserved infrastructureActive and idle time, redundancy, internal network, available capacityActive time only; PUE for site operation
Application serviceOrchestration, RAG, vector database, tools, external APIs, devices and networkTo be completed
Model developmentData preparation, experiments, discarded runs, evaluations and final trainingOne process at a time; no automatic inventory
Hardware life cycleManufacture, transport, maintenance and end of life within the selected LCAProfile manufacture; other phases depend on coverage
Your taskInput → outputSimulator path
Create images, video, speech or musicText → mediaGenerate, then select the medium
Describe a photo or read a scanned documentImages + instructions → textAnalyze images
Summarize video scenesSampled frames + instructions → textAnalyze video, visual track
Transcribe a conversationAudio → textTranscribe audio

The Generate, Analyze media and Train paths each describe a task, model and workload. Server, country, PUE, MFU and lifetime remain editable under assumptions. Closed models are marked when their parameters are assumed.

Understand MFU.

Calculation assumptions
Server: climate impact0.12 gCO2e
Electricity, including PUE0.3 Wh

Configuration used for this calculationMeta - Llama 3.1 405B · NVIDIA DGX H100 (8 GPU)

These values determine the result above and reflect the selected model. “Calculation assumptions” groups the hardware and operating-condition settings.

Selected model

Meta - Llama 3.1 405B

Referenced architecture and size

Architecture
dense
Active parameters
405.87 billion
Total parameters
405.87 billion
Model source

Selected server

NVIDIA DGX H100 (8 GPU)

Hardware profile used as a proxy

CPUs per server
2
GPUs per server
8
Throughput per GPU (TFLOP/s)
989
RAM (GB)
2,000
SSD (GB)
30,000
Power and manufacture
Power per CPU (W)
350
Manufacture per CPU (kg CO₂e)
25
Power per GPU (W)
700
Manufacture per GPU (kg CO₂e)
250
RAM power (W/GB)
0.392
RAM manufacture (kg CO₂e/GB)
1.38802
SSD power (W/GB)
0.0012
SSD manufacture (kg CO₂e/GB)
0.16
Auxiliary power (W)
0
Enclosure manufacture (kg CO₂e)
250

Operating conditions

Electricity region
United States
Electricity factor
0.3548 kg CO₂e/kWh
PUE
1.2
Hardware lifetime
5 years
D4B electricity factors, 2025 snapshot

Calculation and breakdown

Results
Compute load : 405.87 TFLOP
Latency : 26 ms
Processing time : 128 ms
Throughput : 3,898.79 tokens/s
Energy : 0.3 Wh
GPU
CPU
RAM
Storage
Chassis
GHG emissions : 0.12 gCO2e
GPU
CPU
RAM
Storage
Chassis
Operational
Embodied

Result assumptions and limitations

Active assumptions: MFU 40 % · PUE 1.2 · lifetime 5 years. Constant profile power and manufacturing factors, allocated by active time.

Selected case limitation: The 2PT proxy simplifies long-context attention and MoE routing. Prefix caching reduces the prompt only.

Not included: devices, external networks, idle capacity, buildings and application services. Training is not automatically allocated to inference.

Partial estimate to calibrate against duration and energy measurements. All assumptions and limitations

Footnotes​

  1. Allocation framework: SCI and SCI-AI. Online documentation, unpinned version. ↩

  2. Model computation: Kaplan et al., Scaling Laws for Neural Language Models, 2020, Hoffmann et al., Training Compute-Optimal Large Language Models, 2022, Hu et al., LoRA, 2021, Meta, The Llama 3 Herd of Models, 2024. ↩

  3. Jiang et al., Mixtral of Experts, 2024, abstract, § 2. ↩

  4. Hu et al., LoRA, 2021, § 4.1 ; PyTorch, Autograd mechanics, version 2.14, « Setting requires_grad ». ↩

  5. Peebles & Xie, Scalable Diffusion Models with Transformers, 2022. Architecture source; the expressions above are D4B proxies requiring calibration. ↩

  6. Meta, Simple and Controllable Music Generation, 2023 ; Stability AI, Stable Audio Open, 2024. ↩

  7. Qwen, Qwen2.5-VL-7B-Instruct, config.json, 2025, commit cc594898, vision_config / text_config. ↩

  8. Qwen, Qwen2.5-VL Technical Report, 2025, § 2. ↩

  9. OpenAI, Whisper base, config.json, commit e37978b, encoder_layers, decoder_layers, d_model, max_source_positions, max_target_positions. ↩

  10. OpenAI, Whisper audio preprocessing, SAMPLE_RATE, CHUNK_LENGTH, N_FRAMES. Online code, unpinned version. ↩

  11. H100. ↩

  12. PaLM, section 4.1. ↩

  13. GPU performance. Online documentation, unpinned version. ↩

  14. distributed parallelism. Online documentation, unpinned version. ↩

  15. Production measurement: Measuring the environmental impact of delivering AI at Google Scale. Deployment observations are not universal coefficients. ↩

  16. ADEME, RCP des applicatifs numériques, juin 2026, p. 10, 54. The PCR covers services using generative AI, but training before the study period can fall outside its time boundary. Assessing the model life cycle answers a different question; the D4B method retains training and its explicit allocation to uses. ↩

  17. EcoLogits. Online documentation, unpinned version. ↩

  18. More than Carbon (2025). ↩

  19. AI hardware life-cycle emissions (2025). ↩

  20. Moshi research study (2026 preprint). ↩

  21. Video Killed the Energy Budget (2025). ↩

  22. E. Lees-Perasso, D. Ekchajzer, G. Roussilhe et T. De Latour, Analyses de cycle de vie de GPU pour l’intelligence artificielle, ADEME, mars 2026, rapport de 93 pages, § 3.10.5–3.11.1, p. 22–23. ↩ ↩2

  23. N. Jegham et al., How Hungry is AI? Benchmarking Energy, Water, and Carbon Footprint of LLM Inference, v6, 24 novembre 2025, § 4.1–4.3, p. 3–5. ↩

  24. Caravaca, Cuevas and Cuevas, From Prompts to Power, November 2025, preprint v1, sections III-B, IV-A and IV-B. NVML GPU measurements exclude other components and PUE. ↩

  25. Meta, Llama 3.1 405B Instruct, 2024. ↩