Comparing classic and VPC infrastructure on IBM Cloud

Compare the key differences between IBM Cloud classic and VPC infrastructure environments to choose the best option for your workloads and applications.

If you aren't familiar with the environment types, review the following descriptions. Watch the Bare Metal Servers: Classic versus VPC Infrastructure Explainer Video to learn more about the differences between the classic and VPC infrastructures.

The classic infrastructure is the existing Infrastructure as a Service (IaaS) platform. This environment is best for lift and shift workloads so you can move applications quickly and keep the same architecture.
VPC infrastructure is the new IaaS platform, based on software-defined networking and ideal for cloud-native applications.

Key takeaways

VPC infrastructure is the recommended platform for new workloads, offering modern cloud-native capabilities across every dimension. Classic infrastructure remains the right choice for lift-and-shift migrations and workloads that depend on its existing architecture. The most significant differences are:

Compute: VPC provides more profile families, including AI Optimized, Confidential Compute, and Storage Optimized, along with auto scaling and instance groups that classic infrastructure does not offer.
Network: VPC replaces physical and virtual network appliances with built-in cloud-native functions that include VPN-as-a-service, Load Balancer for VPC, and built-in network isolation, simplifying network operations.
Storage: Both environments support block and file storage with encryption and snapshots, but VPC adds optional encryption in transit, cross-account key authorization, and cross-account access for file shares.
Security: VPC provides built-in security groups and network access control lists (ACLs) without requiring third-party appliances.
API: VPC uses a modern REST-based API, replacing the classic SoftLayer API (SLAPI) with a developer-friendly interface aligned with IBM Cloud platform standards.

Compute differentiators

Classic infrastructure offers customizable bare metal and virtual servers, while VPC infrastructure adds cloud-native capabilities such as auto scaling, instance groups, and profiles optimized for AI and confidential computing.

Compute comparison
This table has row and column headers. The row headers identify possible features. The column headers identify the differentiators between classic infrastructure and VPC infrastructure. To understand the differences between environments, go to the row and find the details for the feature that you're interested in.
Category	Classic infrastructure	VPC infrastructure
Services	Virtual Servers Bare Metal Servers Dedicated hosts Reserved virtual servers	Virtual Servers Bare Metal Servers Dedicated hosts Reservations for virtual servers and bare metal servers Instance Metadata service Instance templates Instance groups Auto Scale for VPC
Performance and availability	Networking speeds up to 50 Gbps. For more information, see Configuring network performance.	High-speed networking up to 200 Gbps (see x86-64 instance profiles) Zonal architecture provides better availability
Pricing	Hourly and monthly billing Suspend billing feature for supported configurations	Hourly and monthly billing Suspend billing feature Cost savings for reservations
Bare Metal servers	Customizable servers that feature advanced Intel® Xeon® CPUs, or AMD CPUs, and NVIDIA GPUs	Profile-based servers that feature advanced Intel® Xeon® CPUs, Data Processing Unit (DPU) technology, rapid provisioning, and hourly billing
Virtual server profile families	Balanced Balanced local storage Variable compute Compute Memory Transient option for supported profiles GPU	Balanced Compute Memory Very High Memory Ultra High Memory GPU AI Optimized Storage Optimized Confidential Compute Generations of CPU profiles Profiles for Intel, AMD, and s390x processor architectures
Supported images	Stock images Instance add-ons include OS add-ons, control panel software, and database software Custom images	Stock images Custom images (includes image from volume) Private catalog images
Platform integration		IAM and resource group integration for a unified experience

Network differentiators

Classic infrastructure relies on physical and virtual network appliances, while VPC infrastructure provides cloud-native network functions that include built-in VPN, load balancing, and network isolation.

Network comparison
This table has row and column headers. The row headers identify possible features. The column headers identify the differentiators between classic infrastructure and VPC infrastructure. To understand the differences between environments, go to the row and find the details for the feature that you're interested in.
Category	Classic infrastructure	VPC infrastructure
Location construct	Data centers and Points of Delivery (PODs)	Regional model that abstracts infrastructure so you don't need to worry about pod locations.
Network functions and services	Physical and virtual appliances from multiple vendors	Cloud-native network functions: VPNs Load Balancer as a Service (LBaaS) VPC isolation Multiple vNIC instances Larger subnet sizes
IP addresses	IPv6 addresses supported	IPv4 addresses only
Gateway routing	Handled natively by IBM data center routers, or use a network appliance: Virtual Router Appliance Vyatta Juniper vSRX Fortinet FSA	Public gateway and floating IP services handle traffic routing.
Network address translation (NAT)	Use a virtual or physical network appliance: Vyatta Juniper vSRX Fortinet FSA Fortinet vFSA Bring Your Own Gateway Appliance (BYOGWA)	Supported through floating IP addresses and public gateway functions
IPsec Virtual Private Network (VPN)	Use a virtual or physical network appliance: Vyatta Juniper vSRX Fortinet FSA Fortinet vFSA BYOGWA	Supported by the VPN-as-a-service offering
Elastic load balancing	Cloud Load Balancer	Load Balancer for VPC
Global load balancing	Cloud Internet Services, Citrix Netscaler VPX	Cloud Internet Services
Hybrid connectivity	Direct Link for direct private connectivity from on-premises: Virtual network appliances Physical network appliances (Vyatta, Juniper vSRX, Fortinet FSA, Fortinet vFSA, and BYOGWA)	Connectivity options for on-premises and classic infrastructure resources: Direct Link 2.0 Transit Gateway VPC VPN

Storage differentiators

Both environments support block and file storage with encryption, snapshots, and adjustable IOPS, but VPC storage adds zonal redundancy, cross-account encryption key authorization, and optional encryption in transit.

Storage comparison
This table has column headers. The column headers identify the differentiators between classic infrastructure and VPC infrastructure storage. To understand the differences, find the feature in the classic infrastructure column and compare it with the corresponding VPC infrastructure column.
Classic infrastructure	VPC infrastructure
A robust set of storage services, Block Storage for Classic (Internet Small Computer Systems Interface (iSCSI)), and File Storage for Classic (Network File System (NFS)-based) offerings. Server-side agent-based Backup service with dedicated vault. Snapshot support for both offerings. Cross-regional replication. Adjustable input/output operations per second (IOPS) limits and increasable capacity. Supports encryption at rest with provider- or customer-managed keys. Volume duplication and data refresh from parent volume.	Block Storage for VPC provides primary boot disks (with basic lifecycle management), and secondary data volumes. File Storage for VPC provides NFS-based file shares. Snapshot and backup support for block volumes and file shares. Zonal and cross-regional replication for file shares. Adjustable IOPS and increasable capacity. Supports encryption at rest with provider- or customer-managed keys. Optional encryption in transit for block volumes and file shares. Optional cross-account authorizations for encryption keys and file share access.

Security differentiators

Classic infrastructure uses third-party network appliances for perimeter security, while VPC infrastructure provides built-in security groups and network access control lists for fine-grained traffic control.

Security comparison
This table has column headers. The column headers identify the differentiators between classic infrastructure and VPC infrastructure security options. To understand the differences, find the feature in the classic infrastructure column and compare it with the corresponding VPC infrastructure column.
Classic infrastructure	VPC infrastructure
Vyatta, Fortigate, Juniper vSRX, Security Groups for virtual servers	Security groups, Network Access Control Lists (ACLs)

API differentiators

Classic infrastructure uses the SoftLayer API (SLAPI), while VPC infrastructure provides a modern, REST-based API aligned with IBM Cloud platform standards.

API comparison
Classic infrastructure	VPC infrastructure
Existing SoftLayer API (SLAPI)	New developer-friendly, REST-based API

Next steps

To review all the VPC infrastructure capabilities, see About virtual private cloud. To start exploring infrastructure overall, see Building your infrastructure.