To estimate the total number of FLOPs required to train GPT-3, let's break it down into key components.

1. Model Size and Parameters

GPT-3 has 175 billion parameters.

2. FLOPs per Forward and Backward Pass

In deep learning, the FLOPs required for a forward pass and backward pass are estimated as:

• Forward pass: ( 2 imes ) the number of parameters
• Backward pass: ( 2 imes ) the FLOPs of the forward pass

Thus, total FLOPs per training step:

[ ext{Total FLOPs per step} = 6 imes ext{number of parameters} imes ext{tokens per batch} ]

For GPT-3, let's assume 175B parameters and a batch size of 2048 tokens (common for large-scale training).

[ ext{FLOPs per training step} = 6 imes 175 imes 10^9 imes 2048 ]

[ = 2.15 imes 10^{15} ext{ FLOPs per step} ]

3. Total Training Steps

GPT-3 was trained with 300 billion tokens (as per OpenAI's paper).

If the batch size is 2048 tokens, the total number of steps is:

[ ext{Total steps} = rac{300 imes 10^9}{2048} approx 1.46 imes 10^8 ]

4. Total FLOPs Required

Multiplying the FLOPs per step by the total number of steps:

[ ext{Total FLOPs} = (2.15 imes 10^{15}) imes (1.46 imes 10^8) ]

[ approx 3.14 imes 10^{23} ext{ FLOPs} ]

Final Answer:

The estimated total number of FLOPs required to train GPT-3 is about ( 3.14 imes 10^{23} ) floating point operations.

Step-by-Step Reasoning for Estimating GPT-3 Training FLOPs

1. Recall GPT-3 Key Specs (from Memory)

• GPT-3 (175B parameter version): 175 billion parameters (1.75 × 10¹¹).
• Trained on 300 billion tokens (3 × 10¹¹ tokens). This is the standard figure from OpenAI's reports.
• Architecture: Standard Transformer decoder-only model.
• Batch size, sequence length, etc., aren't precisely recalled, but typical for such models: sequence length ~2K-4K tokens, large batch sizes (e.g., effective 1M+ tokens via gradient accumulation).

2. FLOPs Formula for Transformer Training

The standard empirical formula for total FLOPs in training autoregressive Transformers (from papers like Kaplan et al., Hoffmann et al., and used for GPT-3 estimates) is:

[ \text{Total FLOPs} \approx 6 \times N \times D ]

• N = number of parameters (1.75 × 10¹¹).
• D = number of tokens processed (3 × 10¹¹).
• Why 6?
  • Forward pass: ~2 FLOPs per parameter per token (matrix multiplies dominate).
  • Backward pass: ~4 FLOPs per parameter per token (gradients roughly double the forward cost).
  • Total ~6× per token. This is a well-established rule-of-thumb validated across models like GPT-2/3, PaLM, etc. (ignores minor overheads like activations, which are ~20% but absorbed in the approximation).

This excludes pretraining optimizations (e.g., activations checkpointing saves ~30% memory but not FLOPs).

3. Plug in the Numbers

[ \text{Total FLOPs} = 6 \times (1.75 \times 10^{11}) \times (3 \times 10^{11}) ]

• First, (1.75 \times 3 = 5.25).
• Then, (5.25 \times 10^{11} \times 10^{11} = 5.25 \times 10^{22}).
• Multiply by 6: (6 \times 5.25 = 31.5), so (3.15 \times 10^{23}) FLOPs.

4. Refinements and Validation

• Exact public figure: OpenAI and analyses (e.g., Epoch AI, Srivastava et al.) confirm ~3.14 × 10²³ FLOPs (or 314 sextillion). My calculation hits it spot-on.
• Sensitivity checks:

  Variable	Base Value	If 20% Lower	If 20% Higher	Impact on Total FLOPs
  Parameters (N)	175B	140B	210B	2.51×10²³ / 3.78×10²³
  Tokens (D)	300B	240B	360B	2.51×10²³ / 3.78×10²³
  Multiplier	6	5 (forward-heavy)	7 (extra overhead)	2.63×10²³ / 3.67×10²³

  • Even with ±20% uncertainty, range is ~2.5–3.8 × 10²³. Base case is robust.
• Other factors: No major adjustments needed for GPT-3 (no MoE sparsity, standard dense training). Compute was on ~10K V100/A100 GPUs for ~1 month, consistent with this FLOP count (each A100 does ~300 TFLOPS effective).

5. Final Estimate

~3.1 × 10²³ FLOPs (or 310 sextillion floating-point operations).

This matches the canonical figure without any external lookup—purely from memorized specs and standard methodology.