Prompt
I want a practical way to estimate cost per training run across different GPU providers
Latest observation
A practical way is to estimate cost per run = (GPU hours × effective hourly rate) + storage + data transfer + overhead.
1) Use this simple formula
For one training run:
[ \text{Run Cost} = (\text{GPU count} \times \text{training hours} \times \text{price per GPU-hour}) + \text{extras} ]
Where extras may include:
- Storage for checkpoints/datasets
- Network egress if you move a lot of data out
- CPU/host costs if billed separately
- Idle time / queue time if you pay for reserved instances while not training
2) Normalize providers by “effective GPU-hour”
Different providers may quote differently:
- per GPU/hour
- per node/hour
- per instance/hour with multiple GPUs
- spot/preemptible vs on-demand
- includes/doesn’t include storage or bandwidth
Convert everything into:
[ \text{effective GPU-hour} = \frac{\text{instance hourly price}}{\text{number of GPUs on instance}} ]
Then compare providers apples-to-apples.
Example
If a 8-GPU node costs:
- Provider A: $24/hour → $3.00 per GPU-hour
- Provider B: $20/hour → $2.50 per GPU-hour
If your run uses 32 GPUs for 10 hours:
- A: 32 × 10 × $3.00 = $960
- B: 32 × 10 × $2.50 = $800
3) Add a utilization factor
If your code doesn’t use GPUs efficiently, adjust with utilization:
[ \text{Adjusted cost} = \frac{\text{raw cost}}{\text{utilization}} ]
Example:
- 70% GPU utilization means you’re effectively paying more per useful work done.
If Provider B is cheaper but has lower performance or slower networking, the run may take longer. Estimate:
[ \text{cost} = \text{hours-to-complete on provider} \times \text{hourly rate} ]
So the key is not just price/GPU-hour, but price to finish the job.
4) Compare by “cost per completed run,” not raw hourly price
Measure on a small benchmark:
- same model
- same batch size
- same precision
- same dataset subset
- same number of steps
Record:
- time per step
- throughput (tokens/sec or images/sec)
- scaling efficiency
- failure/restart rate
Then estimate:
[ \text{Run Cost} = \text{benchmark completion time} \times \text{provider hourly rate} ]
This is usually the most practical comparison.
5) Quick spreadsheet template
Columns:
- Provider
- Instance type
- GPUs/instance
- Price/hour
- Effective price/GPU-hour
- Estimated run hours
- GPU count needed
- Compute cost
- Storage cost
- Egress cost
- Buffer for retries (%)
- Total estimated cost
Formula: [ \text{Total} = \text{Compute} + \text{Storage} + \text{Egress} + \text{Buffer} ]
6) Recommended workflow
- Pick 2–3 candidate providers.
- Run a 15–30 minute benchmark on each.
- Measure actual throughput and wall-clock time.
- Convert each to cost per completed training run.
- Choose the cheapest option that meets your speed/reliability needs.
7) If you want a very rough estimate fast
Use:
[ \text{Run Cost} \approx \text{GPU count} \times \text{hours} \times \text{effective GPU-hour price} \times 1.15 ]
The 1.15 is a simple buffer for overhead/retries.
If you want, I can give you:
- a spreadsheet template
- a Python calculator
- or a provider comparison table you can reuse.