Let's talk performance. Expectations for a P5-90 system with 16MB RAM are pretty broad given the contemporary software requirements. Games generally didn't "require" more than a 486DX/66 until the later 90s when MMX became popular, the Pentium II came out, and titles started running in Windows instead of DOS. This P5-90 system should comfortably run most titles through 1997 or so. It should run most of the second generation shooters (e.g., Duke 3D and Quake), and 2D games of the era (Diablo, Civilization II) without much issue. Titles that really push the envelope will be problematic, and upgrading to 32MB should provide plenty of memory headroom for Windows apps (even with Windows 95, 16MB is a practical minimum). Older games that run too fast should be okay in "deturbo" mode that turns off the L2 cache and introduces some NOP cycles. Failing that, conventional "slowdown" utilities can get it even lower.
Basic TopBench benchmark scores around a 250.
In deturbo mode (CTRL-ALT-"-"), this drops to around a 68, which TopBench compares to a high-end 386, which is a sweet spot for a lot of games through 1990/1991. Even demanding Origin games like Wing Commander 1/2 and Ultima VII will run well at this speed.
It was uncommon for game installers to do hardware benchmarks, but once such title is The 7th Guest, aka "Spooky Myst". It tests both CD-ROM and Video Memory speed. For the latter, it doesn't really tell you anything interesting except your performance relative to its own mystery-meat benchmark:
The CD-ROM test is more interesting in that it at least gives you real numbers:
This test is not very impressed with the "24x" CD-ROM drive in this system. Neither am I, really. It's slow, it's loud, it vibrates, and, well, is generally as horrible as all CD-ROMs were at the time. That "300K/sec" benchmark, by the way, is the expected performance of a 2X CD-ROM so either the test is goofy or the CD is.
Finally there is what might be the pickiest DOS-based multimedia game I've ever met, the 1994 Tex Murphy game Under A Killing Moon, which makes use of SVGA VESA modes and recommends at least 12MB RAM.
It has a much better opinion of the CD-ROM drive. It sets the threshold of "fast" for the Video Speed at 5000k/sec and the Mach32's result blows that away. The Mach32 is a bit more problematic than its raw performance, which I'll talk about soon.