@nijam
It depends how far you go back.
Silicon Graphics complete workstation line used to be MIPS based, and DECstations from Digital Equipment Corp. also were powered by MIPS processors overlapping the VAXstations, and the hot Alphastations.
Of course, this was when there were significant differences between proper technical workstations and high-end PCs. MIPS powered two of the five (POWER - IBM. PA-RISC - HP, Sparc - SUN, MIPS - DEC and SGI) major technical workstion platforms, and they also appeared in a number of high performance UNIX minicomputer designs (Pyramid and I think Sequoia spring to mind, but I believe there were others).