# Base Load Capacity SLA

Base load capacity carries an uptime commitment of **99% per GPU
node**, backed by the [credit schedule](#credit-schedule) below: up to
a 100% credit of a node's charges for the measurement period.

A **base load block** is the committed product: a fixed block of GPU
nodes, yours alone for a fixed term at a fixed rate. No bidding and no
preemption. It bills for the full term whether used or not. Demand you
declare beyond the block competes in the [market](https://docs.nationalcompute.com/market.md) as
ordinary preemptible burst capacity.

## Scope

The commitment and its credits apply to **base load capacity only**:
GPU nodes inside a block, for the block's term. Two products are
explicitly outside it:

- **Preemptible burst capacity** — everything on
  [Burst capacity](https://docs.nationalcompute.com/market.md), including nodes an account holds
  beyond its base load block. No uptime credit schedule attaches: a
  node that fails stops [billing](https://docs.nationalcompute.com/billing.md) at the failure, and a
  [protected](https://docs.nationalcompute.com/market.md#minimum-duration-protection) cluster is owed
  a replacement node, but uptime credits are a base load term.
- **Legacy long-term reservations** — capacity sold under earlier
  long-term agreements is governed by those agreements, not by this
  page.

## Uptime measurement

Uptime is measured **for the base load block**, in full-minute
increments, over the shorter of a calendar month or the block's
term — month by month for a longer term, the whole term for a
shorter one. The block's uptime is the share of the block's node-minutes
during which a usable GPU node was serving the block; a
block of eight nodes with one node missing for an hour has lost
one node-hour of its eight.

**Downtime runs from the moment a node fails until a replacement GPU
node is made available** to the block: time spent provisioning
the replacement counts against uptime, not just the failure itself. The
credit tier below is set by the block's uptime and applies to the
block's base load charges for the period; a per-node breakdown is
available from your account team on request.

## Credit schedule

A node whose uptime falls below the commitment earns a credit against
that node's base load charges for the measurement period:

| Uptime per GPU node | Credit |
| :-- | :-- |
| ≥ 99.0% | none — the commitment is met |
| 95.0% – < 99.0% | 10% |
| 90.0% – < 95.0% | 25% |
| 85.0% – < 90.0% | 50% |
| < 85.0% | 100% |

A node below 85% uptime is fully credited — the period costs nothing
for that node.