LightWave 3D started its life on Amiga as a part of the NewTek’s Video Toaster editing system. It evolved in a good stand-alone 3D modeling software and was very popular. However, when Commodore filed for bankruptcy (1994) nobody in the professional market believed in bright future of Amiga. NewTek needed to find a different OS for its products which resulted in support for Windows NT (x86, Alpha) and SGI IRIX (MIPS).
LightWave on SGI was not a very long story. There were only few versions released. The main problem was in price/performance ratio. SGI hardware was expensive and usually it didn’t make much sense to buy it for generic software that is also available for other CPU/OS platforms. LightWave offered way more performance for the same price on Alpha-based Windows NT workstations which was a preferred option for some time. One year later the market shifted to Intel Pentium Pro CPUs with similar performance and broader software support (Windows NT could run only 16bit Intel-x86 software on Alpha).
I have LightWave 3D 5.6 installed on SGI Indigo2 with 250-MHz MIPS R4400 CPU and the rendering performance is only slightly better than on my 133-MHz Pentium MMX-based Toshiba laptop. NewTek apparently didn’t optimize the program to take advantage of SGI hardware.