// features · l1
L1 Blockchain
StackGPU runs a Ethereum-anchored attestation layer dedicated to verifiable GPU computation. Validators don't just settle payments — they re-execute and slash dishonest claims.
Why a dedicated L1
Ethereum already settles billions of dollars in value every day, but it doesn't natively verify GPU computation. StackGPU's L1 is a specialized layer that commits state roots to Ethereum for finality, while running its own consensus optimized for compute-attestation throughput.
What the L1 does
- Receives inference attestations from hosts after each compute cycle. Each attestation contains: input hash, output hash, GPU model fingerprint, timestamp.
- Samples randomly a subset of cycles per epoch and assigns validators to re-execute.
- Compares outputs. If re-execution matches (within numerical tolerance), the host gets paid. If it diverges, slashing kicks in.
- Settles to Ethereum. Every epoch's state root is committed to a Ethereum smart contract for finality.
Architecture diagram
┌──────────────┐ inference job ┌──────────────┐
│ Renter │ ───────────────→ │ Host GPU │
└──────────────┘ ←─ output ─── └──────┬───────┘
│
attestation
│
▼
┌──────────────────┐
│ StackGPU L1 │
│ (attestation, │
│ sampling, │
│ slashing) │
└────────┬─────────┘
│
epoch state roots
▼
┌──────────────────┐
│ Ethereum mainnet │
│ (finality + │
│ settlement) │
└──────────────────┘
Throughput
- Attestations / second: ~12,000 (per current validator set)
- Re-execution sample rate: 2-5% of cycles, randomly assigned
- Time to Ethereum finality: ~12s per epoch commit
- Validator set: targeting 100 active at mainnet maturity
Differences from EVM L1s
| Aspect | EVM rollup | StackGPU L1 |
|---|---|---|
| Optimized for | Smart contract state | Compute attestation |
| Settlement | Ethereum L1 | Ethereum mainnet |
| Sampling | Fraud proofs (week-long) | Same-epoch re-execution |
| Block time | 2-12s | ~12s block cadence |
No "rollup" in the marketing sense
We don't call this a rollup because we don't post tx data to Ethereum for replay — we post commitments and let validators dispute. The economic security model is closer to optimistic rollups with shorter dispute windows enabled by Ethereum finality.