Yeah it was. There are two issues with Deus Ex, one is that it's just very CPU demanding. That Celeron 600 you are using was not exactly a power house by 2000 and even on top end CPUs of the era, the game rarely goes above 30-40fps
Secondly, owing to its Unreal Engine roots, the game runs best on Glide. GeForce cards at the time had to use D3D which meant performance suffered even more.
I've sampled Deus Ex on a Coppermine 1GHz and a Voodoo5, hardware that was top end and very well suited to it at the time, and it usually hanged at 30fps, fairly certain it would be a consistent experience with v-sync on.

There's an older thread you can check out to get a better picture. It's just how it was.

I ran it at a P3-667 with a TNT2 M64 at the time and although I don't remember how smooth it ran I do remember it making a huge difference in loading (and saving!) times when I upgraded my ram from 128 to 384MB.

Enabling EAX also added overhead when Deus Ex was new.

I first ran it on an Athlon 1700+ with a Geforce 2 Ti, in 2002. No issues of course. Ran it at 1024x768.
But that is a little after release.

And it's far above the stated requirements for the game.

I tried it last week with 3.2ghz athlon xp and voodoo5 (2xAA) and it seemed ok, didn't get exact FPS.

It runs quite well on a Celeron-1400 with an overclocked Voodoo3 3500.

The 66MHz FSB was a massive bottleneck to Celerons running faster than ~333MHz. If your board lets you overclock, you might want to try bumping the bus speed to 100MHz. That'll result in a 900MHz CPU, which a Coppermine should have no problem running at.

Secondly, owing to its Unreal Engine roots, the game runs best on Glide. GeForce cards at the time had to use D3D which meant performance suffered even more.

Eh, no. OpenGL renderer should be better and various iterations were provided even before DX9 renderer for Unreal Engine 1.0 was released.

In the summer of 2001 I played it on a PII-350 with 192MB RAM and a GeForce 256. I remember it being fine at 1024x768, and I think I made almost all the way through the game at that time. I later played it on an T-bird 1.4 with 512MB and the same video card. Definitely better. Either way I never had a problem with it.

The Serpent Rider wrote on 2021-01-02, 00:09:

Secondly, owing to its Unreal Engine roots, the game runs best on Glide. GeForce cards at the time had to use D3D which meant performance suffered even more.

Eh, no. OpenGL renderer should be better and various iterations were provided even before DX9 renderer for Unreal Engine 1.0 was released.

talking exclusively on the original game with no modifications at all, of course you can add newer or better renderers but they're talking on launch time

but they're talking on launch time

Vanilla Deus Ex also has OpenGL renderer.

I forgot that it actually shipped with OpenGL support. Fairly certain however that it was about as good or perhaps even worse than the D3D renderer, both in terms of performance and accuracy. My preferred way to play Deus Ex is using DXGLR, but we were talking about launch time or very close to that timeframe. I stand by my claim that Glide runs Deus Ex faster and more consistently than the other renderers offered at the time of release. I seem to remember that it wouldn't allow you to run using 32bit textures, without some .ini tweaking at least, even if you were using VSA-100 based cards.

I played it until the end on a Athlon 750 128mb ram and a Rage 128 pro, later on a geforce 2 mx because the rage was borrowed and I don't remember any issues with it and I think that was fairly close to its release.

Glide didnt support 32bit

Davros wrote on 2021-01-03, 05:20:

Glide didnt support 32bit

Even on v5?

VSA100 cards can force 32-bit render in Glide.

tried mesafx or wickedgl on voodoo 3 to run that game. cant remember which one but with a 800mhz pIII and it ran fine. it was smooth.

Turns out that Unreal Engine games (the ones I've tested at least: both Deus Ex and Rune) default V-Sync to on in Glide mode. Turning it off helps quite a bit. I bought some parts to put a new old PC together so this Celeron will soon be doomed to my closet (or until I find something else to do with it).

I can't remember my PCs specs when I first played Deus Ex, sorry, but I do remember being really pleased at the game. One of the very few times when a game not only delivered what had been promised in the magazine previews, but actually exceeded my hopes. We're talking Half-Life, Goldeneye, Perfect Dark, Timesplitters 2, Bioshock 2, Doom 2016, etc, quality here!

Oh, yes. Deus Ex is my favorite game of all time. However, I've really only played it on hardware much newer than the game itself.