Well, pretty playable. ;-)[b]
The Starmax 5500 has a rage pro card with 4 MB of memory, which makes it the probably the bottom of the barrel in terms of play. I had to set pretty much all of the settings to low or disabled (low detail, low texture detail, flares off, wall markings off, &c.) and I set the res to 400 x 300. But it is playable.
I wasn't able to connect to any of the servers at id (192.246.40.37:27960 through 27963), but I assumed that this was mainly due to servers being full.
MacOS still rules, no matter what Carmack sez. ;-)