How many FPS you can get on a modern graphics card with original DOOM v1.9 for DOS?

[ant]

Hello.

My old school friend and I were wondering. How many FPS you can get on a modern graphics card with original DOOM v1.9 for DOS? No DOSbox, third party engines, mods, etc. Just the original DOS v1.9 DOOM.exe in E1M1 with the default difficulty. Is there a FPS cap? Does it work at all? Also, list the machine setup specifications please.

Thank you in advance. :)

[scifista42]

ant said:

How many FPS you can get on a modern graphics card original DOOM v1.9 for DOS? No DOSbox, third party engines,

The original Doom executable doesn't work at all on modern systems - that's why people have to use either DOSBox, or third party engines.

[Jaxxoon R]

Doom was made before dedicated graphics cards in consumer machines were even a thing, so it hands it all over to the CPU to deal with. The game's locked at 35 FPS and I'm pretty sure it doesn't work at all on a modern system, hence the use of DOSBox.

[Azuruish]

According to Wiki max only 35 frames per second. But not sure.

[Jaxxoon R]

Ninja'd: The Thread the Move the Game

[chungy]

You can load up FreeDOS on a USB stick, boot it, and find out for yourself :P use -timedemo

[riki2321]

I get 35 FPS.

On PrBoom I get 120 FPS.

gt 780 ti.

[fraggle]

Doom itself updates its world at 35fps regardless of the hardware you're running on. So you can only ever see 35fps if you're running with DOS ("Vanilla") Doom.

However, you can use the -timedemo parameter to run the game at the maximum FPS supported by the hardware. In this case the game will run faster than usual and you can get some values that can be converted into FPS.

But it's a tricky question because Vanilla Doom doesn't even run on some modern machines. You can run it in an emulator like DOSbox, but that's adding extra overhead so it isn't really a representative test.

Your question asked about Vanilla Doom, but some source ports such as ZDoom or PrBoom+ support uncapped framerates. The framerate is going to be very dependent on the settings for the source port you're using (what screen size? are you using GL or software rendering? etc.)

There's a further issue in that some modern operating systems / hardware seem to impose arbitrary caps on frame rate. For example I have a Macbook Pro that seems to render its display at 60fps; I can never play back a demo with -timedemo at more than 60fps.

You can get something like a representative sample by using Chocolate Doom which is pretty close to Vanilla Doom and runs on modern hardware. For the most part it's the same code. I tried -timedemo on my Linux desktop (not the Mac) for the Doom shareware demos and get the following results. This is running on an Intel Xeon E5-1650 @ 3.20GHz.

DEMO1:

timed 5026 gametics in 182 realtics (966.538452 fps)

DEMO2:

timed 3836 gametics in 156 realtics (860.641052 fps)

DEMO3:

timed 2134 gametics in 106 realtics (704.622620 fps)

This is running at 320x200 windowed mode, with no aspect ratio correction (which adds extra CPU overhead). So it's pretty close to what Vanilla Doom can do.

One thing to bear in mind is that under DOS you had pretty much direct access to the hardware when writing to the screen. On modern systems the windowing system adds a ton of overhead and hoops you have to jump through. We can kind of simulate this on modern systems with Chocolate Doom by using the -noblit parameter - this goes through all the motions of rendering the screen but doesn't actually do the final step of blitting the result to the hardware. With -noblit added, here are the results:

timed 5026 gametics in 69 realtics (2549.420410 fps)

timed 3836 gametics in 54 realtics (2486.296387 fps)

timed 2134 gametics in 52 realtics (1436.346191 fps)

So to answer your question the best I can with what we have nowadays, my best guess is: easily over 700fps, but anywhere up to 2500fps in theory.

[ant]

Thanks all. :)