Concept card

BDC Capacity Units

As of 2026-07-24T14:00:00Z

Edited by Cédric-Olivier Mâry, sole editor and publication director — 27 years in the SAP ecosystem. How these pages are produced, and where automation is used.

What is BDC Capacity Units?

Idle Joule agents burn 5-10% of a tenant's total CU budget just polling for availability — the least obvious line item in a BDC capacity plan, and the 128-CU entry floor rarely covers a real Tier-1 workload anyway.

Capacity Units are the billing and sizing currency of SAP Business Data Cloud — a bundled measure of compute, memory, storage allotment, and data-flow input/output operations per second, sold in tenant-sized blocks rather than priced per resource. One capacity unit buys roughly one vCPU-equivalent of HANA Cloud compute, about four gigabytes of HANA Cloud memory, a modest storage allotment before overflow pricing kicks in, and a slice of data-flow throughput. The smallest Business Data Cloud tenant starts at 128 capacity units, noticeably larger than a standalone Datasphere tenant's 64-unit floor, reflecting the wider workload mix — replication, live analytics, planning, Joule, Knowledge Graph — that a Business Data Cloud tenant is expected to carry simultaneously. For a consultant sizing an engagement, capacity-unit fluency is the line between a proposal with a predictable monthly bill and the outcome every finance stakeholder dreads: a runaway invoice discovered after go-live.

Why It Matters

Why it matters in practice

A Tier-1 pattern sizes to 130-240 CU steady-state and 280-360 CU at peak — more than double the 128-CU tenant floor, so quoting the floor as sufficient sets up a mid-project capacity crisis.
Memory (~4GB per CU) is the dominant cost driver for in-memory analytics, not compute — a sizing conversation anchored on vCPU count is pricing the wrong variable.
Six distinct workload types (SAC live queries, replication flows, Analytic Model evaluation, Joule grounding, Knowledge Graph traversal, Databricks cluster spin-up) compete for one shared CU pool, so a spike in any one starves the rest.

Key points

1 CU = 1 vCPU + 4 GB HANA + storage + IOPS.
BDC tenant min: 128 CU (€100-180k/yr FY26 entry).
Tier-1 sizing: 130-240 steady, 280-360 peak; provision at peak + 20% buffer.
Six workload types: replication · AM queries · SAC Live · Joule · Knowledge Graph · Databricks side.
Joule idle polling overhead: 5-10% of pool regardless of usage.
Sizing-at-average = anti-pattern (peak doubles average).
Chargeback: per-Space rolling-30d consumption from Tenant Monitor.
Elastic CU bursting in preview Q2 2026, H2 2026 GA target.
BDC Capacity Units is mastered only when it changes a named buyer decision.
Start with the semantic contract and control model before demonstrating the tool.

Terms used on this page

Capacity Unit (CU): BDC's billing primitive: ~1 vCPU + 4 GB HANA Cloud + storage + IOPS combined.
Tenant CU pool: Total contracted CU shared across all workloads in a single BDC tenant.
Sizing at peak: Defensive provisioning to measured peak load + 20% buffer. Default; sizing at average is anti-pattern.
Joule polling overhead: Idle-state Joule agents consuming 5-10% of total CU pool regardless of conversational traffic.
Per-Space chargeback: Allocation pattern using Tenant Monitor rolling-30d Space-level consumption to apportion costs across LoBs.
Tenant Monitor: Built-in BDC dashboard showing CU consumption, query workload, replication health per Space.
Elastic CU bursting: Preview Q2 2026 / H2 2026 GA target — temporary exceeding contracted CU at 1.3-1.5× burst rate, billed quarterly.
Surge billing: Charge applied when tenant exceeds storage allotment or IOPS allotment. Replication parallelism is the most-common cause.

Sources

Full card available to members. What the full card adds: the full decision framework · the SAP vs Snowflake / Databricks / Fabric comparison · the common pitfalls and their fix · the cheat sheet · the architecture schemas · the code blocks · the facts worth quoting.

Open in the app →

Guides that answer with this page

These guides cite this page as one of the sources their answer rests on.