Is Final Doom more demanding than the other iwads?

[invictius]

Picked up a 486dx-33 today - original case, original everything, works after what must be at least 25 years.  I've been poking around on the dos requirements for ultimate and final doom for dos: 386/33 for ultimate with 8mb recommended, final: "designed for 486 or higher" 4mb (no recommended ram).  I get the impression that running plutonia is going to work out to be the same as e1 shareware would on minimal requirements?  Don't want to swap out the cpu for a 486/100 because a) it would be close enough in performance with the p133 I have to not even bother; b) it's a socket that requires force to extract the cpu.

[Nine Inch Heels]

I don't see why final doom would be an issue in terms of performance, and afaik, doom2 ran on 486s fine way back when. What I also don't see is why you don't just install these games and IDCLEV around for a bit to see for yourself...

[axdoomer]

Final Doom has more open areas and the levels are more complex in general. Doom 2 required a 386DX 33 MHz, but in levels like MAP13 Downtown, it must have been slow. 

[R13]

There's also much more going on in Plutonia levels, so I guess this also contributes.

[NightmareZer0]

I would assume Plutonia would be more demanding just for the simple fact of how many monsters the maps have.

[RjY]

Funnily enough Plutonia is the least populated of the iwads. (UV, single player counts)

   3262 /usr/share/games/doom/plutonia.wad
   3348 /usr/share/games/doom/doomu.wad
   3818 /usr/share/games/doom/doom2.wad
   5271 /usr/share/games/doom/tnt.wad

There are 8 maps in TNT with more monsters than the most populated Plutonia map (32): 18 08 07 14 21 09 20 27

 

Other than that, I don't have any simple numbers to hand to show it, but my gut feeling is TNT's maps are generally much larger, use more textures, and require more memory than Plutonia's.

 

[fraggle]

For the most part, if we're talking "minimum system specs" in the literal sense of the phrase, then no, there shouldn't be a lot of difference. There's probably no technical reason why Final Doom can't run on a 386 with 4MB of RAM.

 

However, there's a difference between the bare minimum and the "playable" minimum. Personally I wouldn't recommend bothering on anything less than a 486 with 8MB of RAM. I've played Doom on 386s and it's so slow that it's not really worth bothering. When the framerate is that low you're not really experiencing the game as it was intended - you might as well play something else that's going to be enjoyable on a machine like that.

 

Now, to get down a bit into the technical details of why there might plausibly be a different bare minimum between Ultimate Doom and Vanilla Doom:

 

The big thing as I see it is the RAM. Doom has a clever memory caching system that stores things that have been loaded from disk in memory. Things are loaded and discarded as the need arises. If you have a lot of RAM, it might be able to cache the entire contents of the IWAD file in RAM, and then after a few minutes playing you'll probably never see the little blue disk flash at the bottom of the screen again. But if you have very little RAM (say, 4MB) then it's going to be continually loading things and throwing them away.

 

A simple example to explain what I mean: suppose that you shoot an imp. The game has to play the sound effect that the imp makes when it's in pain, so it has to load it from disk into RAM. Then perhaps you open a door and there's a new room with a Mancubus in it. The sprites for the Mancubus aren't in RAM, so it has to load them to show them on screen. If you have very little system RAM then it might be that the imp sound effect gets thrown away to make room for the sprites. Next time you shoot an imp it'll have to load them all over again. If you had more RAM this wouldn't be necessary.

 

So there are things which can make a difference even though the game engine itself is identical between the two games. For example if you're playing some really huge, complex levels, that takes more RAM. I get the impression that the Doom 1 levels were pretty carefully crafted and tested with an eye for staying within memory limits, and I doubt that's true for the Final Doom levels. Another thing to consider is the additional monsters in the Doom II IWADs that aren't in Doom 1. That's a bunch more sprites and sound effects to keep in RAM. All this additional demand for RAM makes the game slower and less playable (as mentioned, it's already pretty much unplayable on a 386), but you can also just straight up run out of RAM too, and the game will crash. Probably they decided to bump the requirements just to set the right expectations, but by the time Final Doom came out (1996) requiring a 486 was a perfectly reasonable request.

[axdoomer]

In a short part of this video, he plays with a 486 DX 33. The benchmarks later in the video says it runs at 15 FPS.

 

If your hard-drive is very old, expect the loading to be very slow. 

 

 

Edited April 14, 2017 by axdoomer

[esselfortium]

On 4/13/2017 at 2:50 PM, NightmareZer0 said:

I would assume Plutonia would be more demanding just for the simple fact of how many monsters the maps have.

Aside from Go 2 It, though, Plutonia's maps generally have relatively few monsters.