PSU 101: Indigo 4000 vs Indigo 3000 PSUs


irix detailer
Feb 8, 2019
Hello, today in PSU 101 we'll take a quick look at a common issue: PSUs for SGI Iris Indigos. There are two versions of the Indigo, the R3000 and the R4000 which correspond to the version of the MIPS CPU in each. They have completely different motherboards and gfx, so the power requirements are different as well.

Many of these PSUs are dying or near death and if you are ordering 'used but working' PSUs from online you need to know what you are getting.

In a nutshell, thanks to info from IanM I can say simply:

  1. Indigo R4000 systems need a 34 AMP PSU
  2. Indigo R3000 systems need a 25 AMP PSU
  • You can always use a working 43A PSU in a R3000 Indigo.
  • Using a 25A in a R4000 may work initially but will hasten it's death

I have an image of a R4000 variant, as that is what I have. I have a working and non-working unit. They have different revs and come from different years.

First, to identify what PSU you have examine the label in detail:


As long as you can id the Output AMPs, you can be sure of which PSU will work in your Indigo. Good Luck.

Iris Indigo- the most beautiful SGI ever created.
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