---
name: "gem"
section: "4"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["linux", "freebsd", "openbsd"]
url: "https://new.carta.tech/gem/4"
---

# gem(4)

GEM/GMAC Ethernet device driver

## NAME

**gem** – GEM/GMAC Ethernet device driver

## SYNOPSIS

To compile this driver into the kernel, place the following lines in your kernel configuration file:

**device miibus** **device gem**

Alternatively, to load the driver as a module at boot time, place the following line in [loader.conf(5)](/loader.conf/5.md):

```
if_gem_load="YES"
```

## DESCRIPTION

The **gem** driver provides support for the GMAC Ethernet hardware found mostly in the last Apple PowerBooks G3s and most G4-based Apple hardware.

All controllers supported by the **gem** driver have TCP checksum offload capability for both receive and transmit, support for the reception and transmission of extended frames for [vlan(4)](/vlan/4.md) and a 512-bit multicast hash filter.

## HARDWARE

Chips supported by the **gem** driver include:

- Apple GMAC

- Sun GEM Gigabit Ethernet

The following add-on cards are known to work with the **gem** driver at this time:

- Sun Gigabit Ethernet PCI 2.0/3.0 (GBE/P) (part no. 501-4373)

## SEE ALSO

[altq(4)](/altq/4.md), [miibus(4)](/miibus/4.md), [netintro(4)](/netintro/4.md), [vlan(4)](/vlan/4.md), [ifconfig(8)](/ifconfig/8.md)

## HISTORY

The **gem** device driver appeared in NetBSD 1.6. The first FreeBSD version to include it was FreeBSD 5.0.

## AUTHORS

The **gem** driver was written for NetBSD by Eduardo Horvath ⟨*eeh@NetBSD.org*⟩. It was ported to FreeBSD by Thomas Moestl ⟨*tmm@FreeBSD.org*⟩ and later on improved by Marius Strobl ⟨*marius@FreeBSD.org*⟩. The man page was written by Thomas Klausner ⟨*wiz@NetBSD.org*⟩.