Vanilla or source portwads that struggled on a pentium 1/2?

[invictius]

The earliest wad I can think of that needed more than an original pentium is phobos anomoly reborn. I didn't play much doom between the 586 and pentium 4 eras, were there even any vanilla/early boom/early zdoom wads that needed a pentium 2?

[Graf Zahl]

With vanilla you must consider that it was heavily restricted by the visplane and drawsegs limits. This alone limited geometry quite considerably.
More I cannot tell, I already used a high-res port and more powerful CPU when I got back into Doom in 1998 after abandoning it for other games in 1995 so I cannot say how the more complex mods of the time would have fared on a low end system.

[invictius]

With vanilla you must consider that it was heavily restricted by the visplane and drawsegs limits. This alone limited geometry quite considerably.
More I cannot tell, I already used a high-res port and more powerful CPU when I got back into Doom in 1998 after abandoning it for other games in 1995 so I cannot say how the more complex mods of the time would have fared on a low end system.

Would you expect something like eternal doom to be slow on a windows port, on a late-model pentium/early pentium 2? Most demanding vanilla wad I can think of.