# Flex versus Dedicated boundary: ops-per-second pricing and missing features > Source-anchored research for Flex versus Dedicated boundary: ops-per-second pricing and missing features. Run status: COMPLETED. Parent: [Cluster Tier Limits and Feature Gates as Cost Drivers (Connections, IOPS Caps, Minimum Tiers)](https://llms-explorer.com/tree/cluster-tier-limits-and-feature-gates-as-cost-drivers-connections-iops-caps-minimum-tiers/) · 5 facets · 14 facts · page: https://llms-explorer.com/tree/flex-versus-dedicated-boundary-ops-per-second-pricing-and-missing-features/ ## How it works - Flex lacks private endpoints, network peering, database auditing and customer-managed encryption keys. A workload requiring any of these features crosses the tier boundary even when its traffic and storage fit Flex. (high confidence) (verified as of 2026-10-14) — [source](https://www.mongodb.com/docs/atlas/reference/flex-limitations.md) ## Measurements and reference values - MongoDB advertises Flex at $8–$30 monthly; the base includes 5 GB storage, 100 ops/sec and unlimited data transfer. The cap describes Flex cluster charges, not a budget guarantee for an entire application or Atlas organization. (medium confidence) (verified as of 2026-10-14) — [source](https://www.mongodb.com/docs/atlas/billing/atlas-flex-costs.md) ## Problems, failure modes and limitations - Flex caps combined read/write throughput at 500 ops/sec. Above that limit, Atlas applies per-connection cooldowns and queues operations, which may wait over a second. Paying the highest Flex rate does not purchase additional throughput. (high confidence) (verified as of 2026-10-14) — [source](https://www.mongodb.com/docs/atlas/billing/atlas-flex-costs.md) - Flex cannot deploy sharded clusters. Atlas Core M10/M20 support replica sets only; M30+ supports sharding. Therefore shard-key and resharding cost analysis must include the eligible Dedicated tier boundary. (high confidence) (verified as of 2026-10-14) — [source](https://www.mongodb.com/docs/atlas/reference/flex-limitations.md) - One Flex user reported a failed Flex-to-M10 upgrade, a prolonged rollback, and rejected connections; a later comment reported manual migration to a fresh M10. This is an unverified individual incident, not a measured failure rate. (low confidence) (verified as of 2026-10-31) — [source](https://www.reddit.com/r/MongoDB_Official/comments/1wr97d1/atlas_flex_cluster_aws_mumbai_lost_its_primary/) - Flex cannot be deployed as a sharded cluster. Consequently, using shard-key placement or resharding as a cost lever requires leaving Flex for an eligible sharded Dedicated configuration; merely selecting the cheapest Dedicated replica set does not establish sharding eligibility. (medium confidence) (verified as of 2026-10-14) — [source](https://www.mongodb.com/docs/atlas/reference/flex-limitations.md) - Prisma's provisioning tutorial treats tier selection, private network access, version control and backup requirements as explicit setup decisions. Its separate Free, Flex and Dedicated walkthrough supports choosing a deployment by operational requirements; its rate and limit table explicitly derives from MongoDB documentation. (low confidence) — [source](https://www.prisma.io/dataguide/mongodb/mongodb-atlas-setup) ## Comparisons and alternatives - Flex limits storage to 5 GB, measured as uncompressed BSON documents plus their indexes; it does not auto-expand storage. Reaching this boundary calls for a Dedicated deployment rather than buying another Flex storage band. (high confidence) (verified as of 2026-10-14) — [source](https://www.mongodb.com/docs/atlas/billing/atlas-flex-costs.md) - MongoDB lists five Flex throughput bands: 0–100, 100–200, 200–300, 300–400 and 400–500 ops/sec, at $0.0110, $0.0205, $0.0288, $0.0356 and $0.0411 per hour respectively. Billing follows time spent at each usage level, rather than a flat monthly tier or a fee for each individual operation. (low confidence) (verified as of 2026-10-14) — [source](https://www.mongodb.com/docs/atlas/billing/atlas-flex-costs.md) ## Facts and statements - Flex bills hourly by ops/sec band: 0–100 costs $0.0110/hour, 100–200 $0.0205, 200–300 $0.0288, 300–400 $0.0356, and 400–500 $0.0411. Published monthly charges range from $8 to a $30 cap. (low confidence) (verified as of 2026-10-14) — [source](https://www.mongodb.com/docs/atlas/billing/atlas-flex-costs.md) - Flex lacks private endpoints, network peering, customer-managed encryption keys, database auditing, and continuous backup/PITR. It also lacks Performance Advisor, downloadable database logs, configurable memory/storage, and dedicated search or analytics nodes. (low confidence) (verified as of 2026-10-14) — [source](https://www.mongodb.com/docs/atlas/reference/flex-limitations.md) - PointFive's original cost-review method checks data plus index size, peak Opcounters and connections, and dependencies on unavailable features before selecting Dedicated-to-Flex migration candidates. This is a workload-screening method, not independent measurement of MongoDB's prices. (low confidence) (verified as of 2026-10-30) — [source](https://www.pointfive.co/efficiency-hub/inefficiencies/dedicated-mongodb-atlas-cluster-for-workloads-that-fit-a-flex-cluster) - Dedicated M10/M20 still use burstable infrastructure and can throttle after burst periods; upgrading from Flex to the cheapest Dedicated tier does not establish unlimited or sustained compute capacity. (low confidence) (verified as of 2026-10-14) — [source](https://www.mongodb.com/docs/atlas/manage-clusters.md) - Flex has a fixed daily snapshot starting 24 hours after creation, but no on-demand snapshots, custom snapshot policy, continuous backup or point-in-time restore. A requirement for finer recovery granularity can justify Dedicated independently of throughput. (high confidence) (verified as of 2026-10-14) — [source](https://www.mongodb.com/docs/atlas/reference/flex-limitations.md)