---
name: "ssm"
section: "4"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["openbsd"]
url: "https://new.carta.tech/ssm/4"
---

# ssm(4)

Scalable Shared Memory

## NAME

**ssm** – Scalable Shared Memory

## SYNOPSIS

**ssm\* at mainbus0**

## DESCRIPTION

The **ssm** driver provides support for the Scalable Shared Memory devices found on Serengeti and Starcat systems. These devices are used to connect snoopy coherency domains together in a coherent fashion to build systems with more than 24 CPUs.

## SEE ALSO

[intro(4)](/intro/4.md)

## HISTORY

The **ssm** driver first appeared in OpenBSD 4.4.

## AUTHORS

The **ssm** driver was written by Mark Kettenis ⟨*kettenis@openbsd.org*⟩.