IRIX OEM gigabit cards command a premium online, often over $100USD. However, with a bit of engineering it's possible to modify cards using the Broadcom BCM5704 chipset to appear as SGI ethernet cards P/N 9210289.
To do so, install the card in a GNU/Linux machine with an open PCI-X slot, and use ethtool:
ethtool -E (interface) magic 0x669955aa offset 0xa4 value 0x80
ethtool -E (interface) magic 0x669955aa offset 0xa5 value 0x13
ethtool -E (interface) magic 0x669955aa offset 0xa6 value 0x10
ethtool -E (interface) magic 0x669955aa offset 0xa7 value 0xa9
This has been shown to work on the following cards:
Alteon ACEnic 10/100/1000
Compaq NC7770 Gigabit Server Adapter (With the Tigon3 chipset)
A Broadcom 5704 chipset PCI-X card example3Com 3C996 10/100/1000 PCI-X Server Network Interface Card (With the Tigon3 chipset)
IBM NetXtreme 1000 T
From community reports. The source of this post is a thread from the days of Nekochan.net: