Are burstable compute options available?
Yes, Burstable Instances are available in OCI and are one of the most effective ways to reduce rental costs for "quiet" servers that only occasionally need full power.
In a standard OCI instance, you pay for 100% of the CPU capacity 24/7. With a burstable instance, you agree to a lower baseline of CPU power in exchange for a significant discount.
When you create a burstable VM, you specify two things:
Total OCPUs: The maximum "ceiling" the server can hit (e.g., 1 OCPU).
CPU Baseline: The amount of CPU you are "guaranteed" at all times. OCI offers two baseline levels:
12.5% of the OCPU
50% of the OCPU
The "Burst" mechanic: If your server is idling at 5% and suddenly needs to process a task, it can "burst" up to 100% of the OCPU for a limited time (typically up to 1 hour of continuous bursting) as long as it has been underutilizing its resources recently.
The pricing is tied directly to the baseline, not the ceiling.
If you rent a 1 OCPU instance with a 12.5% baseline, you are only billed for 0.125 OCPUs per hour.
This represents a significant cost reduction compared to a standard instance, making it ideal for microservices or small web servers.
Burstable instances are perfect for workloads that are "spiky" rather than "steady":
Microservices: Services that sit idle until a specific API call is made.
Dev/Test Environments: Servers that developers use intermittently throughout the day.
Small Web Servers: Sites with low baseline traffic that occasionally get a small surge of visitors.
CI/CD Agents: Build runners that only work when code is pushed.
No "Guaranteed" Burst: Because burstable instances run on oversubscribed hardware, OCI does not guarantee you will be able to burst to 100% exactly when you need it. If the physical host is extremely busy, your burst might be throttled.
Memory does NOT burst: While the CPU can jump from 12.5% to 100%, your RAM is fixed. If you provision 8GB of RAM, you have 8GB regardless of the CPU state.
Time Limit: Bursts are generally designed for short durations (up to 1 hour). If you try to run at 100% CPU for 5 hours straight, the system will eventually throttle you back down to your baseline (12.5% or 50%).
| Feature | Standard Flexible VM | Burstable VM (12.5% Baseline) |
| CPU Availability | 100% Guaranteed | 12.5% Guaranteed (100% Peak) |
| Billing Rate | 100% of Shape Price | 12.5% of Shape Price |
| Oversubscription | No | Yes |
| Ideal For | Production DBs, Heavy Apps | Microservices, Dev/Test |