DOOM II runs extremely well under Windows 95, if you know how to set it up properly. And I'm talking about right off the desktop. Network games in Windows 95 are indistinguishable from DOS network games, though modem-to-modem is a little shaky. For modem games I recommend booting out to DOS (perhaps even using the DETH boot options definied previously! Just add your network drivers to the AUTOEXEC.BAT).
Anyway, here are the optimal settings for DOOM II under Windows 95.
Right click on the DOOM II shortcut to bring up the shortcut menu
and then click on Properties to bring up the Properties dialogue box.
Click on the Memory tab and change the following settings to the numbers show in bold red:
These are the optimal memory settings, assuming you've got 16MB of RAM. That may be assuming a lot to some folks, but Windows 95's sweet spot is16MB. Even with 8MB or 12MB, I've found these settings to work quite well on a DX2-66, DX4-100, and my P100.
You probably don't need to change anything here, but make sure that "Usage: Full Screen" is checked. DOOM 1.666 and up, The Ultimate DOOM, and DOOM II will not run in a window. (HERETIC will run in a window, but that's because it uses the 1.2 DOOM engine. For what it's worth, DESCENT runs nicely in a window, too.)
Pretty important stuff here: Uncheck "Foreground: Allow screen saver"; uncheck "Background: Always suspend"; and slide the "Idle Sensitivity" to Low.
And that is all there is to it.
The preceding settings are optimal for just about any DOS-extended game. A couple of tips for HEXEN: if you get a "stacks" error message while starting HEXEN in Windows 95, chances are you've got the Microsoft PLUS! Pack installed, along with an active screen saver. Turn your screen saver off, restart Windows, and then try again. You should be okay, then. Other than that, I've found that HEXEN runs just spiffy with the same settings as DOOM.
DUKE NUKEM 3D is another story. Sometimes it runs, sometimes it doesn't. Under Properties, hit the Program tab, then choose the Advanced button and try checking "Prevent MS-DOS based program from Detecting Windows." After that, your guess is as good as mine. Potluck.
I've found that the Frames Per Second benchmark test in Rich "Weeds" Nagel's Video Benchmark Calculator provides more accurate and realistic results than the Superscape 3D Benchmark most folks use. Weeds' program runs a demo in DOOM II itself and calculates the realtime FPS. The following are comparisons between running DOOM II in DOS, and then using my recommended settings in Windows 95:
As you can see, the DOS FPS is not significantly higher than Windows 95.
Download Video Benchmark Calculator for DOOM II (31k) or Superscape 3D Benchmark (59k).