October 4, 2022 . 2 MIN READ
It is correct that Provisioned IOPS (P-IOPS) carries a significant price premium compared to General Purpose SSD (gp2/gp3) storage. In the Tokyo region, for a Single-AZ deployment, the storage costs $0.15/GB and $0.12 per provisioned IOP.
With a minimum entry point of 100GB and 1000 IOPS, the baseline cost starts at $135/month (excluding instance fees). For smaller workloads, this can indeed represent a 100x increase in storage costs compared to standard tiers.
Whether the performance justifies the cost depends entirely on your application’s latency requirements and I/O consistency.
Consistency is Key: Unlike General Purpose storage, which relies on a “burst” credit system, P-IOPS provides a consistent, low-latency I/O ceiling. This is critical for high-throughput applications where a “credit exhaustion” event would cause a catastrophic spike in database wait times.
The Scaling Reality: Research and benchmarks indicate that performance scaling with P-IOPS is remarkably linear. Moving from 1,000 to 2,000 IOPS generally doubles your throughput for random read/write operations.
While standard EBS volumes (gp2) provide a baseline of 3 IOPS per GB (with a minimum of 100), P-IOPS allows you to hit much higher targets regardless of volume size.
The 100 to 1000 Jump: Moving from a standard volume (approx. 100 IOPS) to the P-IOPS minimum (1,000 IOPS) represents a 10x increase in raw disk throughput. For a performance-critical database, this can be the difference between a responsive UI and a timed-out request.
The decision to use P-IOPS should be driven by technical requirements rather than just budget:
Enterprise/Performance Critical: If your company operates at a scale where every millisecond of latency translates to lost revenue, the 100x cost increase is a reasonable “insurance policy” for guaranteed performance.
Small to Medium Business (SMB): If you are managing costs for a smaller entity, the most efficient path is usually to scale up the instance type (increasing CPU and RAM) or increase gp3 throughput first.
The Middle Ground: Modern gp3 volumes often bridge this gap by allowing you to provision higher IOPS and throughput independently of storage size at a much lower cost than P-IOPS (io1).
Recommendation: Before committing to P-IOPS, monitor your DiskQueueDepth and Read/WriteLatency in CloudWatch. If your latency is high but your BurstBalance is full, your bottleneck may be CPU/RAM, not the disk itself.
Reference:
https://stackoverflow.com/questions/18777070/aws-rds-provisioned-iops-really-worth-it
