Lightning AI
One of the smoother on-ramps to serious GPU compute: persistent Studio environments, per-second billing, and a free tier real enough to prototype on. The catch is the credit system — advertised plan prices are the floor, and actual spend is dominated by metered GPU hours on top.
Pros
- Free tier includes an always-available CPU Studio and starter GPU credits
- Per-second GPU billing with interruptible instances up to 80% cheaper
- Same environment moves from prototyping to multi-node training
- SOC 2, HIPAA and VPC options for enterprise deployments
Cons
- Credit arithmetic (credits vs GPU-hours vs plan quotas) takes effort to predict
- Phone number required at signup; free Studios restart every 4 hours
- Best experience assumes the PyTorch/Lightning ecosystem