Having singlehandedly saturated the eBay Indy market for a while, I decided to try something else with one of the ones I had laying around.
I made Music Player Daemon box out of it! I may even contribute a tardist to the Nekoware archives here in a few weeks.
It took a bit to get everything sorted out with library locations & some of the other libraries I needed for everything (id3tag was the only one I had to custom compile), but I got it running in an evening. It's mounted my NFS music share, and is happily churning away quietly on top of my stereo.
I didn't realize this until after it was in place, but the volume buttons work! It's the best-suited of the SGIs to stereo-top use - very low power, thin, reasonably light, and volume buttons!
On a R5k 180mhz, it's not even taxing it - ~10% CPU utilization playing back normal MP3s/OGGs. Not really using much memory either, for that matter, and I know I have some services running that I could shut down.
CPU: 87.8% idle, 9.3% usr, 2.4% ker, 0.5% wait, 0.0% xbrk, 0.0% intr
Memory: 192M max, 177M avail, 124M free, 128M swap, 128M free swap
So, yea. If anyone wants more info on compiling MPD for IRIX, let me know. And, as I said, I may get around to putting together a few more tardists so it's included in the Nekoware archive.
The other observation I have is that... a blue Indy looks out of place in an audio rack. I'm thinking of using one of the skins that's beat to death & painting it, either gloss black, metal fleck grey, or something steampunk (sort of a rusted iron look).