What is the difference between OCPUs and vCPUs in OCI?

An OCPU in OCI represents a physical CPU core with hyper-threading, equivalent to two vCPUs in most other cloud providers. So a 4 OCPU shape gives you 8 vCPUs of processing power. This distinction is important when comparing OCI pricing to AWS or Azure — a 4 OCPU OCI instance is comparable to an 8 vCPU instance elsewhere. OCI prices are listed per OCPU, so the effective per-vCPU cost is half the listed OCPU rate.

What are flexible shapes and how do they save costs?

Flexible shapes let you choose the exact number of OCPUs (1 to 64 for most shapes) and memory (1 to 64 GB per OCPU) your workload needs, rather than selecting from fixed sizes. You pay only for the resources you configure. This eliminates the waste of provisioning a fixed shape with 32 GB RAM when your workload only needs 12 GB. Flexible shapes are available for AMD (E4, E5), Intel (Optimized3), and Arm (A1, A2) processors.

Which OCI shape family is best for general-purpose workloads?

For general-purpose workloads, the VM.Standard.E4.Flex (AMD EPYC) and VM.Standard.A1.Flex (Arm Ampere Altra) shapes offer the best price-performance ratio. The A1 Flex shape is particularly cost-effective and is included in the Always Free tier (up to 4 OCPUs and 24 GB RAM). For workloads that require x86 compatibility, the E4 Flex shape provides a good balance of compute, memory, and network bandwidth at competitive pricing.

OCI Compute Shape Finder

ComputeOCI

Find OCI compute shapes by vCPU, memory, and workload type including Ampere ARM.

Last verified: May 2026

Shape Requirements

Min OCPUs

Min Memory (GB)

Architecture

Shape Type

Max Price/Hour ($) - Optional

Raw Output

Output will appear here...

About This Tool

OCI offers a wide range of compute shapes spanning AMD, Intel, and Arm-based processors, with both fixed and flexible configurations. Flexible shapes (like VM.Standard.E4.Flex and VM.Standard.A1.Flex) let you choose exact OCPU and memory ratios, while fixed shapes provide predetermined configurations. Choosing the right shape requires understanding OCPU pricing differences between processor families, network bandwidth allocations, local NVMe storage availability, and GPU options. The Compute Shape Finder helps you filter and compare shapes based on your workload requirements, showing pricing, performance characteristics, and availability by region.

Real-World Scenario

Your team needs 20 VMs for a containerized microservice fleet (8 vCPU equivalent, 32 GB RAM each). The finder compares: VM.Standard.E4.Flex (AMD) at 4 OCPUs + 32 GB = $122/month each = $2,440 fleet/month; VM.Standard.A1.Flex (Arm) at 4 OCPUs + 32 GB = $66/month each = $1,320 fleet/month. After verifying the apps run on Arm (Java, Node, Python all do), the team picks A1 Flex and saves $1,120/month vs the AMD option, $14K/year saved.

When to Use This Tool

•Finding the most cost-effective shape for a Java application server that needs 8 OCPUs and 64 GB RAM across AMD, Intel, and Arm options
•Identifying GPU shapes available in your target region for machine learning training workloads
•Comparing bare metal versus VM shapes for Oracle Database workloads that require high I/O and local NVMe storage
•Evaluating Arm-based A1 shapes versus AMD E4 shapes for containerized microservices where per-OCPU cost matters most

Pro Tips

TIP

OCPU vs vCPU is the most-confused metric across clouds. 1 OCPU = 1 physical core with hyper-threading = 2 vCPUs. When comparing OCI list prices ($0.025/OCPU/hr) to AWS ($0.04/vCPU/hr), divide OCI's price by 2 for an apples-to-apples comparison. Net effect: OCI compute is genuinely cheaper than AWS/Azure for equivalent compute.

TIP

Arm-based A1 Flex shapes are the best value across OCI for general workloads — and the Always Free tier includes 4 OCPUs / 24 GB RAM permanently free. For dev/test, hobby projects, or even small production workloads, this is the most generous free tier across any cloud.

TIP

Bare metal shapes (BM.Standard, BM.DenseIO) cost similar to large VM shapes per OCPU but provide dedicated hardware — no neighbor noise, full local NVMe access. For Oracle Database, SAP HANA, or other workloads that benchmark well on dedicated hardware, BM is often dramatically faster than VM at similar cost.

How It Works Under the Hood

The finder filters OCI's compute shape catalog by your stated requirements (OCPUs, memory, processor family AMD/Intel/Arm, GPU presence, bare metal vs VM, network bandwidth tier, local NVMe presence) and returns matching shapes sorted by per-OCPU monthly cost. For flexible shapes, it lets you specify exact OCPU + memory and computes the resulting cost based on the per-OCPU and per-memory-GB rates.

Frequently Asked Questions

What is the difference between OCPUs and vCPUs in OCI?: An OCPU in OCI represents a physical CPU core with hyper-threading, equivalent to two vCPUs in most other cloud providers. So a 4 OCPU shape gives you 8 vCPUs of processing power. This distinction is important when comparing OCI pricing to AWS or Azure — a 4 OCPU OCI instance is comparable to an 8 vCPU instance elsewhere. OCI prices are listed per OCPU, so the effective per-vCPU cost is half the listed OCPU rate.
What are flexible shapes and how do they save costs?: Flexible shapes let you choose the exact number of OCPUs (1 to 64 for most shapes) and memory (1 to 64 GB per OCPU) your workload needs, rather than selecting from fixed sizes. You pay only for the resources you configure. This eliminates the waste of provisioning a fixed shape with 32 GB RAM when your workload only needs 12 GB. Flexible shapes are available for AMD (E4, E5), Intel (Optimized3), and Arm (A1, A2) processors.
Which OCI shape family is best for general-purpose workloads?: For general-purpose workloads, the VM.Standard.E4.Flex (AMD EPYC) and VM.Standard.A1.Flex (Arm Ampere Altra) shapes offer the best price-performance ratio. The A1 Flex shape is particularly cost-effective and is included in the Always Free tier (up to 4 OCPUs and 24 GB RAM). For workloads that require x86 compatibility, the E4 Flex shape provides a good balance of compute, memory, and network bandwidth at competitive pricing.

Related Learning Guides

OCI Compute Shapes & Instances18 min read
OCI Cost Optimization Strategies18 min read

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