What is a mainframe?
Mainframes are data servers designed to process up to 1 trillion web transactions daily with the highest levels of security and reliability.
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Mainframes are computers

At their core, mainframes are high-performance computers with large amounts of memory and data processors that process billions of simple calculations and transactions in real time. A mainframe computer is critical to commercial databases, transaction servers, and applications that require high resiliencysecurity and agility.

How do mainframes work?

IBM mainframe computers are uniquely engineered to:

  • Run common operating systems like Linux®, specialized operating systems such as IBM z/OS®, and software that takes advantage of unique hardware capabilities.
  • Support massive simultaneous transactions, data processing and throughput (I/O) with built-in capacity on demand and built-in shared memory for direct application communication.
  • Deliver the highest levels of security with built-in cryptographic cards and innovative software. For instance, the latest IBM Z® mainframe systems can execute up to 1 trillion secure web transactions per day and manage privacy by policy.
  • Offer resiliency through multiple layers of redundancy for every component (power supplies, cooling, backup batteries, CPUs, I/O components, cryptography modules) and testing for extreme weather conditions.
What does a mainframe look like?

Today’s mainframe computers are much smaller than the early “Big Iron” machines. With a standard 19” rack, the latest mainframe seamlessly coexists with other platforms in the data center. One IBM Z single-frame system requires 75 percent less floor space than x86 2U servers running the same workloads and throughput – and reduces power consumption by 40 percent.

Sustainability on modern mainframes

Learn how IBM mainframes can reduce energy consumption by 75%, space by 50%, and the CO2e footprint by over 850 metric tons annually.¹

Related links

Learn more about the newest IBM mainframe: IBM z16™

See what a modern mainframe looks like in 3-D
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¹ Consolidating Linux workloads on 5 IBM z16 systems instead of running them on compared x86 servers under similar conditions can reduce energy consumption by 75%, space by 50%, and the CO2e footprint by over 850 metric tons annually.

DISCLAIMER: Compared 5 IBM Machine Type 3931 Max 125 model consists of three CPC drawers containing 125 configurable cores (CPs, zIIPs, or IFLs) and two I/O drawers to support both network and external storage versus 192 x86 systems with a total of 10364 cores. IBM Machine Type 3931 power consumption was based on inputs to the IBM Machine Type 3931 IBM Power Estimation Tool for a memo configuration. x86 power consumption was based on March 2022 IDC QPI power values for 7 Cascade Lake and 5 Ice Lake server models, with 32 to 112 cores per server. All compared x86 servers were 2 or 4 socket servers. IBM Z and x86 are running 24x7x365 with production and non-production workloads. Savings assumes a Power Usage Effectiveness (PUE) ratio of 1.57 to calculate additional power for data center cooling. PUE is based on Uptime Institute 2021 Global Data Center Survey (link resides outside ibm.com). CO2e and other equivalencies that are based on the EPA GHG calculator (link resides outside ibm.com) use U.S. National weighted averages. Results may vary based on client-specific usage and location.