What is the difference between OCPU and vCPU in OCI?

An OCPU (Oracle Compute Unit) corresponds to a physical CPU core with hyper-threading, providing two hardware execution threads (equivalent to two vCPUs in other clouds). When comparing OCI pricing to AWS or Azure, note that 1 OCPU equals 2 vCPUs. This means an 8-OCPU OCI instance is roughly equivalent to a 16-vCPU instance on other platforms. OCI prices per OCPU, so divide by 2 when comparing per-vCPU prices.

How do Flex shapes reduce costs compared to standard shapes?

Flex shapes (like VM.Standard.E5.Flex) let you choose the exact number of OCPUs (1-94) and memory (1-64 GB per OCPU) for each instance, so you only pay for what you need. Standard shapes come in fixed sizes that may over-provision resources. For example, if your workload needs 4 OCPUs and 8 GB RAM, a Flex shape costs exactly that, while a standard shape might force you into a 4-OCPU/32-GB configuration. Flex shapes typically reduce costs by 20-50% through right-sizing.

OCI Compute Cost Estimator

ComputeOCI

Estimate OCI compute costs for flex shapes, GPU instances, and boot volumes.

Compute Configuration

Compute Shape

OCPUs

Memory (GB)

Hours per Month

730 hours = full month.

Include Always Free Tier (4 A1 OCPUs + 24 GB RAM)

Raw Output

Output will appear here...

About This Tool

OCI Compute costs depend on the instance shape (Flex, Standard, Dense I/O, GPU, HPC), OCPU and memory configuration, storage volumes, networking, and operating system licensing. OCI's pricing model is often simpler than other clouds — no charge for data ingress, and OCPU pricing includes both vCPUs in the hardware thread. This estimator calculates monthly Compute costs based on your shape selection, OCPU/memory configuration, expected usage hours, and storage attachments, helping you compare options and optimize spend.

When to Use This Tool

•Estimating monthly costs for a fleet of VM.Standard.E5.Flex instances with custom OCPU and memory ratios for a microservices application
•Comparing costs between AMD (E5), Intel (Standard3), and Ampere (A2) shapes for a workload to find the best price-performance ratio
•Budgeting for GPU instances (VM.GPU.A10, BM.GPU.H100) for machine learning training and inference workloads
•Calculating the cost savings of using preemptible instances for fault-tolerant batch processing versus on-demand instances

Frequently Asked Questions

What is the difference between OCPU and vCPU in OCI?: An OCPU (Oracle Compute Unit) corresponds to a physical CPU core with hyper-threading, providing two hardware execution threads (equivalent to two vCPUs in other clouds). When comparing OCI pricing to AWS or Azure, note that 1 OCPU equals 2 vCPUs. This means an 8-OCPU OCI instance is roughly equivalent to a 16-vCPU instance on other platforms. OCI prices per OCPU, so divide by 2 when comparing per-vCPU prices.
How do Flex shapes reduce costs compared to standard shapes?: Flex shapes (like VM.Standard.E5.Flex) let you choose the exact number of OCPUs (1-94) and memory (1-64 GB per OCPU) for each instance, so you only pay for what you need. Standard shapes come in fixed sizes that may over-provision resources. For example, if your workload needs 4 OCPUs and 8 GB RAM, a Flex shape costs exactly that, while a standard shape might force you into a 4-OCPU/32-GB configuration. Flex shapes typically reduce costs by 20-50% through right-sizing.

Related Learning Guides

OCI Cost Optimization Strategies18 min read

Disclaimer: This tool runs entirely in your browser. No data is sent to our servers. Always verify outputs before using them in production. AWS, Azure, and GCP are trademarks of their respective owners.