why does doom3 not lagg as much with low fps?

[saaya]

heya

i noticed that d3 laggs a LOT less than other games at low fps!

even at 20fps the game is well playable, while other games like ut2k4, far cry etc are almost impossible to play at only 20fps as they lagg a lot.

how come? does it have to do with the internal 60hz lock?

 

[AlphaWolf]

I haven't played D3, so I'm not sure that this is the correct answer, but the pace of the game often contributes to how low a framerate you can get away with. Games like splinter cell are pretty slow moving and you can get away with a low framerate.

 

[Lezmaka]

My guess would be the slower gameplay. If something is really fast paced, you move more "game distance" for lack of a better term in each frame, so when framerate slows down, it seems pretty jerky. If it's slow paced, you move less "game distance" in each frame, so when framerate is low, things don't seem quite as bad.

 

[a688]

I'm gonna have to disagree w/ the above two and suggest its to do with the 60 hertz lock. I believe its allowing everything to to react at the same speed regardless of how many frames your video card is drawing (whether it be 20 or 60).

 

[kyleb]

i was thinking the same thing a688, just a guess but it seems like something is different about the engine. as for the slower gameplay comments, i take it you two have not played much of the game?

 

[pcchen]

I think many games feel "laggy" because their minimum frame rates are too low. For example, I played CMR4 and felt it lags on my computer, but when I use FRAPS to test its frame rate, it averages at pretty high (50 ~ 60 fps). However, when I wrote a program to display it's frame rate distribution, there are occasionally some frames at 1x fps. That's why I find it's laggy, I think.

Doom 3's average frame rate is lower, but it seems that the minimum frame rate is at about 2x fps, rarely go to 1x fps. I think that's probably why it feels smoother.

 

[radar1200gs]

It's a tick lock, not a hz lock and that is why the game is smoother.

Doom3 operates internally at 60 ticks per second, quake3 only does 30 per second by comparison. This gives the games twice as many opportunities per second of reacting to what the player is doing. You see that as smooth fluid movement on screen.

 

[Ollo]

It's a tick lock, not a hz lock and that is why the game is smoother.

Doom3 operates internally at 60 ticks per second.

Coincidently, that is the definition of 60 Hz. 8)

 

[radar1200gs]

It's a tick lock, not a hz lock and that is why the game is smoother.

Doom3 operates internally at 60 ticks per second.

Coincidently, that is the definition of 60 Hz. 8)

yes, you can say it's 60 hertz (hertz is nothing more than a frequency measurement), but it has nothing to do with graphics rendering.

In ID games the tick rate is how often the engine checks input, samples its world and the characters within etc and creates a current game state.

The 3d renderer runs alongside the game engine and outputs the current 3d portion of the game state to the graphics card. It can do this at a rate independent of the tick rate, and can output the same state (identical frames) multiple times per tick depending on the speed of the 3d subsystem of the machine.

 

[K.I.L.E.R]

yes, you can say it's 60 hertz (hertz is nothing more than a frequency measurement), but it has nothing to do with graphics rendering.

That is a frequency measurement.

 

[radar1200gs]

yes, you can say it's 60 hertz (hertz is nothing more than a frequency measurement), but it has nothing to do with graphics rendering.

That is a frequency measurement.

"it" in the above quote pertains to the tick rate.
Now, are we quite through with the smart-arse replies?

 

[Nappe1]

frequency can measure other frequencies than refresh rates as well. If you swing your left arm twice in a second, your arm has 2Hz swinging frequency. if you eat 4 times in 24 hours, you have 4 / (24 Hours *60 Minutes *60 Seconds) = 4 / (24 Hours * 3600 Seconds) = 4,6296296296296296296296296296296e-5 Hz eating frequency.



as simple as that.

 

[CouldntResist]

heya

i noticed that d3 laggs a LOT less than other games at low fps!

even at 20fps the game is well playable, while other games like ut2k4, far cry etc are almost impossible to play at only 20fps as they lagg a lot.

I dont have D3 yet, but according to my experience with other games, I can say the lag is definitely Direct3D specific.

During last 5 years I used to own high end cards, only recently I went cheap and got myself gf5200. This revealed to me all the "joy" of playing games with input lag, a phenomena previously unknown to me.

As an experiment, try 2 following Humus' demos on a low end card:
SelfShadowBump (a D3D demo)
Portals (an OGL demo)

Both demos have comparable pixel shader complexity and they run at the same framerate (20-21 FPS) on my system. However SelfShadowBump gives me terrible, over half second input lag (I estimate, of course). In the Portals I dont feel any lag at all.[/url]

 

[Dave B(TotalVR)]

You dont think it has anything to do with John Carmack being a genius?

 

[Lezmaka]

I'm gonna have to disagree w/ the above two and suggest its to do with the 60 hertz lock. I believe its allowing everything to to react at the same speed regardless of how many frames your video card is drawing (whether it be 20 or 60).

What I meant by fast/slow gameplay was for the most part the walk/run speed of your character, but what you said might make more sense.

 

[Gery]

I found out that turning vsync on or reducing the prerender limit to 1(0) in the nvidia driver settings greatly reduced the lag at low fps (at the cost of a few fps).

 

[K.I.L.E.R]

yes, you can say it's 60 hertz (hertz is nothing more than a frequency measurement), but it has nothing to do with graphics rendering.

That is a frequency measurement.

"it" in the above quote pertains to the tick rate.
Now, are we quite through with the smart-arse replies?

No!

"It" is a frequency.