I have two Pentium PRO builds. One is an Dell Dimension XPS 200n.
Pentium PRO 200 MHz, 256 KB cache
64 MB EDO RAM
HDD 6,4 GB Hdd
SCSI CD Rom
Jazz Rush 6 MB, 3dfx Voodoo Rush
Sound Blaster AWE 64 Gold
ISA 10/100 3Com network card
OS: Windows NT 4.0
Windows 98 se
Second one:
ALR Revolution 2x server
Two slotket's ( Slot 1 to Slotket 8 converter) with
2 x Pentium Pro 200 MHz 256KB cache,
4x128 MB ECC Edo Ram,
36 GB Scsi Hdd, 18 GB Scsi Hdd, 6 GB IDE Hdd, 3,5" Fdd,
Sony SDT-9000 DDS Scsi backup drive,
Nec MultiSpin 4Xi Caddy Scsi Cdrom drive,
Video card Matrox Millenium 2MB wram pci ,
3D accelerator Quantum3D Obsidian2 Sbi 24MB,
Mylex i960 Pci Raid controller 8MB cache,
Intel PRO 100+ dual port 10/100 ethernet card,
SoundBlaster AWE 32 Isa sound card
OS: Windows NT 4.0, Windows XP, BeOS 5
The performance compared with Pentium class cpu is very strong in games which use intense FPU. In Windows Xp it works pretty well. Unreal and Quake I, II runs at decent frame rates of course courtesy of the 3dfx accelerator.
From my personal testings, in software which uses 16 bit code, the performance of a Pentium PRO 200 is compared with a Pentium 166 MHz, but in 32 bit apps is like Pentium 233 MMX at least, even 266 when FPU is used a lot.