Why teams typically experience 50% (or greater) cost reductions when moving from DynamoDB to ScyllaDB
DynamoDB is expensive at scale. Some of that cost is fundamental to the managed service model. But much of it is the pricing model, the way DynamoDB charges per read, per write, per byte, and per region. ScyllaDB rethinks pricing from first principles. The result: teams typically see more than 50% cost reductions on equivalent workloads. In this post, I’ll share a few reasons why.
Cheap writes
DynamoDB charges 5x more for writes than reads. Write a 1 KB item and it costs 5 write capacity units. Read the same 1 KB item and it costs 0.25 read capacity units.
ScyllaDB pricing is based on provisioned cluster capacity (nodes), not per operation. Whether you do 10K writes/sec or 100K writes/sec on a 3-node cluster, the ScyllaDB cost remains the same. Write-heavy workloads for AI, real-time analytics, logging, time-series data and IoT sensors often see the biggest savings.
Take a look at our AI Feature Store example. A batch workload scenario with overnight peaks approximately 3x the daytime average on DynamoDB will cost $2.2M/year. The same workload on ScyllaDB would cost $145K/year. In other words, that’s at least 15x savings just switching to ScyllaDB.
No need for a separate cache
DynamoDB’s baseline latency is in the 10-20ms range. For many applications, that’s unacceptable. In those cases, teams commonly deploy DAX, Redis, or Memcached on top. That adds cost, complexity, and another service to operate and monitor.
ScyllaDB was built for low latency. Internal caching and a shard-per-core architecture deliver sub-millisecond latencies on reads. For most workloads, an external cache is unnecessary.
Let’s look at a retail example with a read-heavy workload that is cached and running on demand. On DynamoDB running with DAX, that workload would cost $1.6M/year. The same workload on ScyllaDB would cost $271K/year (and even less if you switch to a hybrid plan).
That’s at least 6x cheaper using ScyllaDB. Plus: there are fewer moving parts, simpler operations, and no cache coherency headaches.
Affordable multi-region data centers
DynamoDB Global Tables charge replicated writes (rWCUs) at a premium: roughly 2x the cost of normal writes. Moreover, cross-region data transfer incurs AWS’s standard rates: $0.02-0.09/GB. For a workload doing 10K writes/sec with 5 KB payloads across 2 regions, data transfer alone can add $10K+/month.
A social media scenario modeled across 3 regions on DynamoDB would cost $11.0M/year. The huge cost is partly because the write capacity cannot be reserved, and you effectively pay twice for the writes. The same workload on ScyllaDB would cost $591K/year. That’s a monstrous +$10M/year saving by switching to ScyllaDB.
ScyllaDB handles multi-DC replication natively. You provision nodes in each data center, and replication is built into the protocol along with shard-aware and rack-aware drivers. This helps minimize network overhead and avoids the per-operation premium. You pay for the cluster nodes; replication comes with the territory.
Large items don’t cost more
In DynamoDB, a 1 KB write costs 1 WCU, and a 10KB write costs 10 WCUs. Item size directly drives billing. This incentivizes shrinking payloads, compressing data, and splitting tables. Architectural decisions are driven by cost, not design.
A simple on-demand scenario with DynamoDB using 3 KB item sizes would cost $633K/year. ScyllaDB would cost $39K/year. Along with multi-region, item size remains one of the biggest cost levers to pull when looking for savings on DynamoDB.
ScyllaDB billing is independent of item size. Store 1 KB items or 100 KB items and the cluster cost is unchanged. You architect around performance and correctness, not billing thresholds.
Making multi-tenancy work for you
DynamoDB is multi-tenant infrastructure. That’s how AWS achieves efficiency. But it also means:
- You pay for provisioned capacity
- AWS oversubscribes hardware
- Idle capacity benefits AWS, not you
You pay for the full machine, but AWS shares it with everyone else. Multi-tenant infrastructure reduces cost for AWS but increases risk for users. Large DynamoDB outages (like us-east-1) impact thousands of customers simultaneously. When shared infrastructure fails, the blast radius is enormous.
ScyllaDB flips that model.
You get a dedicated cluster, which gives you:
- Isolation by design
- The ability to run multiple workloads
- The option to share idle capacity internally
This is especially powerful for:
- Multi-tenant SaaS
- Microservices
- Multiple environments (dev/staging/prod)
Instead of provisioning 100 tables separately, you provision one cluster and use it fully. You control your infrastructure. AWS monetizes multi-tenancy. ScyllaDB lets you monetize it.
Flexible and predictable pricing
DynamoDB is excellent for certain use cases: serverless applications with unpredictable spikes, multi-tenant services that need table-level isolation, and teams that prioritize operational simplicity over cost. But if you’re running a predictable, scale-intensive workload – especially one that’s write-heavy, multi-region, or stores large items – then DynamoDB’s per-operation pricing model becomes a massive cost driver.
ScyllaDB’s node-based, cluster-centric model is fundamentally more cost-efficient for these scenarios. Combined with its performance and operational features, it’s why teams see more than 50% cost reductions.
Want to see the actual numbers for your workload? Use the ScyllaDB Cost Calculator at calculator.scylladb.com to model a comparison between your current DynamoDB spend and equivalent ScyllaDB infrastructure.
