How is storage performance tier selected?
Here is how you select your performance tier today:
When you create or edit a volume, you choose from four primary tiers based on VPUs per Gigabyte:
| Tier | VPUs / GB | Max IOPS / Volume | Best For... |
| Lower Cost | 0 | 3,000 | Large logs, streaming, data warehouses. |
| Balanced | 10 | 25,000 | Default. Most workloads, boot disks. |
| Higher Performance | 20 | 50,000 | Large databases, high-speed apps. |
| Ultra High (UHP) | 30–120 | 300,000 | AI training, mission-critical SQL/NoSQL. |
In OCI, performance is a calculation of your Volume Size × VPUs.
Linear Scaling: As your volume gets larger, its performance baseline grows automatically.
The "Slider" Advantage: You can change your tier at any time without a reboot. If you start on Balanced but notice your database is lagging, you can slide it to Higher Performance in the console. The change takes effect in seconds.
To pick the right tier, ask yourself what your application values most:
Throughput Intensive? If you are moving massive files (sequential I/O), the Lower Cost tier is often sufficient because it provides high throughput even with low IOPS.
Random I/O Intensive? For databases where you are constantly reading/writing small bits of data from different places, you need the high IOPS of Balanced or Higher Performance.
Extreme Latency Needs? If your app requires sub-millisecond response times at massive scale, use Ultra High Performance. Note that UHP usually requires a Bare Metal server or a large VM shape to handle the massive 300,000 IOPS pipe.
If you don't want to manually select a tier, you can enable Performance-based Auto-tuning:
Set a Floor: Choose your minimum performance (e.g., Balanced).
Set a Ceiling: Choose your maximum performance (e.g., Ultra High Performance).
OCI Takes Over: The system monitors your disk usage. When it sees an I/O spike, it automatically increases your VPUs (and your hourly rate). When the spike ends, it scales you back down to your "Floor" to save money.
| Tier | Monthly Storage Cost | Monthly VPU Cost | Total (Est.) |
| Lower Cost | $25.50 | $0.00 | $25.50 |
| Balanced | $25.50 | $17.00 | $42.50 |
| Higher Performance | $25.50 | $34.00 | $59.50 |
| Ultra High (120) | $25.50 | $204.00 | $229.50 |
The storage tier you select is only half the battle. Every server (Compute Shape) has a Max Network Bandwidth. If you attach an Ultra High Performance volume (300,000 IOPS) to a tiny 1-core VM that is capped at 1 Gbps, your storage will be "throttled" by the server's network limit. Always match your storage tier to a server shape that can handle the throughput.