Doom 3 + 6800 series = Buzzkill?

[DigitalEmperor]

Uh, oh. So after all I have read I started to realize something that is going to be a MAJOR issue for me. I guess instead of coming at this from a "omgz0rz .. nVidia is teh sux" I am going to try to get some information straight first.

Is it true the 6800 series cards do not support triple buffering in Doom 3?
Is it true the x800 series cards DO support triple buffering in Doom 3?

The reason I ask these two questions is, without triple buffering, using vsync means that framerates are chopped up. Say the refreshrate of my monitor is set to 85hz, if it can't keep up with that framerate wise (and it won't due to the engine being limited to 60fps) with vsync + double buffering, the framerate is chopped in half to 42.5fps. It can't exceed that, and if it's not able to keep up with 42.5fps, it'll chop down further to 21.25fps. Not really all that sweet huh? Maybe my understanding of this is flawed but it seems to hold up with what i've read.

If ATI offers triple buffering, that means that the "actual" framerate can be rendered and not chopped up and halved like double buffering. That'd be a SERIOUS advantage to those gamers out there who can NOT play with image tearing. I am one of those gamers. Tearing basically will make a game non-playable for me. Vsync is an absoult MUST. Thing is, even if ATI can't keep up with the 6800's .. with triple buffering, it'd end up hanging out @ higher framerates overall than the 6800's.

Now I am not "calling nvidia out" or anything on this, as I don't have EITHER of these cards I am not really biased. I do have a 6800GT on order, and I would like to know what to expect.

Is it possible to maybe enable triple buffering for Doom 3 with the 6800s already? Or might this be available in a driver update?

Now note: if you usually do not play with vsync this whole conversation is moot because the 6800's are a clear winner when not using vsync.

 

[rayg]

triple buffering sucks though b/c it slows down your input commands significantly

 

[DigitalEmperor]

triple buffering sucks though b/c it slows down your input commands significantly

Does this significantly affect gameplay? Doom 3 is hardly the "twitch" game that something like CS or UT2k4 is. I admitidly know very little about triple buffering.

 

[rayg]

ive never used it, i dont think it hurts gameplay that badly, but some people notice a little bit of lag. I can tell you that i get a little bit of tearing in doom3 but i can barely see it when it happens because its so dark.

 

[Leright]

screen tearing has never bothing me. V-sync is a waste of clock cycles.

 

[DigitalEmperor]

screen tearing has never bothing me. V-sync is a waste of clock cycles.

then as i said in my original post, it's a moot issue for you. thank you for letting us know you don't like vsync though

 

[Leright]

then as i said in my original post, it's a moot issue for you. thank you for letting us know you don't like vsync though

no prob, bob.

 

[joemama]

Does this significantly affect gameplay? Doom 3 is hardly the "twitch" game that something like CS or UT2k4 is. I admitidly know very little about triple buffering.

Oh...yes it is. You'll be doing plenty of twitching in this game. Don't let the slow plodding look of the still image screenshots fool you..

 

[planetary]

OK. I know less about triple buffering than you do. I thought it was an option to make the game look better. Please break it down for me.

 

[DigitalEmperor]

i honestly don't know all of the complexities of triple buffering, but I do know that when its enabled with ATI cards, and vsync is on, the framerate is rendered normally. When double buffering and vsync is on (both nvidia and ati) the framerates divide based on refreshrate and what the system is able to render at.

Example:

Refresh Rate: 85hz
Actual Framerate: 52fps
Triple Buffering + Vsync Framerate: 52fps
Double Buffering + Vsync Framerate: 42.5fps

Now, basically what happens is .. with double buffering and a refresh rate of 85hz, framerates will be 85fps, 42.5fps, 21.25fps .. notice how it cuts it in half. Well, what determines the framerate is if the system can keep up. If you drop below 42.5fps with double buffering and vsync, you're framerate will drop to 21.25. Pretty crappy considering 21.25 = choppy and unplayable .. and 30-35fps = very playable.

I am not an expert here, and some of my information may be wrong, so if anyone wants to jump in and help me out to better understand i'd appreciate it. This is how I am seeing it go down though.

 

[Yonkec]

I wasent under the impression that triple buffering slowed down the graphics, but i very easily could be wrong ;D

taken from some info from Microsoft about DX7:

" In some cases, that is, when the display adapter has enough memory, it may be possible to speed up the process of displaying your application by using triple buffering. Triple buffering uses one primary surface and two back buffers.
You do not need to keep track of all surfaces in a triple buffered flipping chain. The only surfaces you must keep pointers to are the primary surface and the back-buffer surface. You need a pointer to the primary surface in order to flip the surfaces in the flipping chain, and you need a pointer to the back buffer for blitting. For more information, see Flipping Surfaces.
Triple buffering allows your application to continue blitting to the back buffer even if a flip has not completed and the back buffer's blit has already finished. Performing a flip is not a synchronous event; one flip can take longer than another. Therefore, if your application uses only one back buffer, it may spend some time idling while waiting for the IDirectDrawSurface7::Flip method to return with DD_OK. "

triple buffering is also only useful if vsync is enabled i think

 

[burningrave101]

Your information and stats look pretty accurate as to what i've read. Triple buffering does a good job of lessening the impact of fps loss from v-sync. I dont use v-sync though because its really not necessary on descent CRT's unless your playing an older game where your getting really high fps. I dont notice tearing when my fps is under my refresh rate and because my refresh rate at 1600x1200 is 85Hz, i dont usually go over that. V-sync has also been known to lead to that "stuttering" effect some people experience in-game.

 

[ohgod]

I have vsync on in Doom 3 and my fps usually stays pegged at 60fps. I dont know if that helps you or not. Like somone else said it is very hard to notice the tearing in Doom 3 unless your really looking for it, I dont think you'll see it during normal gameplay.

 

[tranCendenZ]

I found that using refresh rate override in the NV control panel and setting refresh to 100hz (up from 60hz) at 1600x1200 greatly reduced the tearing to the point where I don't really notice it. Also, doing this does not have the halving effect of VSYNC or the mouse lag effect of triple buffering.

 

[Lazn_Work]

No it is not chopped in half, that is not how it works.

Yes there is a significant decrease in FPS, but not half.

see: http://www.extremetech.com/article2/0,1558,1158477,00.asp

"Triple buffering is also useful for benchmarking graphics boards as it partially alleviates the problem of V-sync interference with measuring 3D performance. The graphics chip can keep working and rendering information into the second back buffer—even when the first back buffer is rendered, and ready to be swapped to the front, but waiting for the V-sync interval. Without a triple buffer, with Vsync enabled, the graphics chip would have to wait for the single back buffer to flip to the front. Only then could it start rendering to the "new" back buffer (which was just previously the front buffer). A triple buffer allows the graphics chip rendering to not stall as frequently as with a double buffer, thus improving overall performance. "

So as soon as the Vsync interval is reached, it can move on to rendering the next frame, it doesn't cut anything in half.

==>Lazn

 

[tranCendenZ]

No it is not chopped in half, that is not how it works.

Yes there is a significant decrease in FPS, but not half.

Actually that's exactly how it works with standard vsync (double buffering).

If you have 120hz refresh, your framerates can be 120fps, 60fps, 30fps, 15fps, 7.5fps etc.

Your above explanation of how vsync behaves with triple buffering, not just plain vsync with double buffering which is the default. Triple buffering can partially alleviate the halving effect of standard double buffering, but introduces input/mouse lag, making it less desirable for FPS games.

In my case, Doom3 @ 1600x1200 @ 100hz with vsync disabled yields best results. I suggest others attempt to raise their refresh rate using refresh rate override in the NV control panel, it alleviated my tearing problems and kept me at high frames with no mouse lag.

 

[DigitalEmperor]

i wish i had an ATI card to play with just to feel the mouse lag which is being discussed. it'd be intresting to see if i notice it, and if it really would affect my gameplay experience.

at any rate, thank you for the added information guys, i appreciate it.

 

[tranCendenZ]

i wish i had an ATI card to play with just to feel the mouse lag which is being discussed. it'd be intresting to see if i notice it, and if it really would affect my gameplay experience.

at any rate, thank you for the added information guys, i appreciate it.

IMO its not really too big an issue unless you plan to play at 1600x1200 and your only option is 60hz. If your monitor supports a refresh rate higher than 60hz, simply disabling vsync and raising the refresh via refresh override can alleviate tearing problems to the point where you won't notice them. And you won't suffer from any input lag either.

 

[Joose]

Please explain (as i'm not actually sure) why vsync would be wanted/needed

 

[tranCendenZ]

Please explain (as i'm not actually sure) why vsync would be wanted/needed

The poster is stating the tearing without vsync would be distracting, and since there is currently no way to enable triple buffering with 6800 cards, it means he will suffer framerate fluctuations (halving) as a result of enabling vsync due to the taxing D3 engine. You are able to use triple buffering override with ATI cards, however this also produces an unwanted mouse lag side effect that can be quite annoying especially in fps games.

My response was to simply disable vsync and change the refresh rate via refresh rate override until one is found where tearing is minimal - worked great for me, as I now get little noticable tearing and high framerates without the input lag tripple buffering would incur. (1600x1200 @ 100hz)

 

[Lazn_Work]

Actually that's exactly how it works with standard vsync (double buffering).

If you have 120hz refresh, your framerates can be 120fps, 60fps, 30fps, 15fps, 7.5fps etc.

Your above explanation of how vsync behaves with triple buffering, not just plain vsync with double buffering which is the default. Triple buffering can partially alleviate the halving effect of standard double buffering, but introduces input/mouse lag, making it less desirable for FPS games.

In my case, Doom3 @ 1600x1200 @ 100hz with vsync disabled yields best results. I suggest others attempt to raise their refresh rate using refresh rate override in the NV control panel, it alleviated my tearing problems and kept me at high frames with no mouse lag.

http://www.extremetech.com/article2/0,1558,1158477,00.asp

No not at all:

"The most common technique is called "double buffering," so termed because there are two buffers (or frames of animation). These are called the front and back buffers. The front buffer is always the current frame of animation being displayed, whereas the back buffer is the next frame of animation that the 3D chip is working on. When the next frame of animation is ready, the 3D card driver does a page-flip. The front buffer now becomes the back buffer and vice versa, and the process repeats.

The result of double buffering is that subsequent frames can be displayed more smoothly. Page flips typically are synchronized with the CRT's vertical blanking interval (VBI), also called "Vsync" or "vertical sync". During the VBI, the CRT's electron beams are turned off and repositioned from bottom-right to top-left and turned back on for the next scan pass. When flipping the back buffer to the front during this "Vsync interval", users will not perceive any abnormal flickering of the image."

It doesn't have to be half the refresh rate, just a multiple of the refresh rate. So with a refresh rate of 120 it could be 40 because 3*40=120 etc.

==>Lazn

 

[tranCendenZ]

It doesn't have to be half the refresh rate, just a multiple of the refresh rate.

Heh what exactly is your point?

If vsync is on with double buffering and your refresh rate is 120hz, your fps cannot go higher than 120hz. It can only be 120fps, or if it drops below that its halved to 60fps, below that its halved again to 30fps, or halved again 15fps, etc. You can test this for yourself with fraps and vsync on any game.

 

[DigitalEmperor]

the problem occurs when you don't have an extremely high quality monitor that is able to do 100hz @ 1600x1200. I am currently limited to 72hz .... Even the new monitor I am looking at possibly picking up only does 85hz @ 1600x1200. 100mhz @ 1600x1200 translates to a pretty expensive display.

 

[Lazn_Work]

Heh what exactly is your point?

If vsync is on and your refresh is 120hz, your fps cannot go higher than 120hz. It can only be 120hz, or halved - 60fps, or halved again -30fps, or halved again 15fps, etc. You can test this for yourself with fraps and vsync on any game.

I edited above, it could be 40 because 3*40=120 it doesnt have to be the number 2 that you devide by, as long as it is a whole number.

and even that is not entirely true, because you can get partial fps, eg: 20.7fps (I know that is what I get in D3 with double buffer on and vsync enabled)

==>Lazn

 

[tranCendenZ]

the problem occurs when you don't have an extremely high quality monitor that is able to do 100hz @ 1600x1200. I am currently limited to 72hz .... Even the new monitor I am looking at possibly picking up only does 85hz @ 1600x1200. 100mhz @ 1600x1200 translates to a pretty expensive display.

So have you tried disabling vsync and using refresh rate override at 72hz or 85hz on any other game you own? You can see for yourself how it will look.

 

[DigitalEmperor]

So have you tried disabling vsync and using refresh rate override at 72hz or 85hz on any other game you own? You can see for yourself how it will look.

yes, it doesn't look BAAADD, i had learned to override the 60hz refreshrates when I was using my 9800 Pro but I never really knew what triple buffering or double buffering was when I had that card. now I am looking back and I don't remember which I was using, but I know for a fact that I was using vsync because the tearing was obnoxious. the thing is, i deffinatly still NOTICE it .. and its distracting to a point. it would be nice if there was some sort of technology like triple buffering which would prevent tearing, allow full framerate, and also have no mouse lag.

 

[tranCendenZ]

I edited above, it could be 40 because 3*40=120 it doesnt have to be the number 2 that you devide by, as long as it is a whole number.

Ah I see what you are saying now, yeh that is correct. I thought you were saying that there was no halving of framerate with vsync, which is the first thing that happens when you drop below refresh using vsync. If your refresh rate is 100 and you drop below 100, the refresh rate will be halved, that is the smallest multiple. It is true though if you further drop below 50 then, that it could drop to another multiple, say 33.3fps (100/3).

and even that is not entirely true, because you can get partial fps, eg: 20.7fps (I know that is what I get in D3 with double buffer on and vsync enabled)

==>Lazn

Likely a measuring error of the benchmarking tool if the framerate is jumping around if its fluxuating a lot and not a multiple of the refr hz.

 

[Lazn_Work]

Ah I see what you are saying now, yeh that is correct. I thought you were saying that there was no halving of framerate with vsync, which is the first thing that happens when you drop below refresh using vsync. If your refresh rate is 100 and you drop below 100, the refresh rate will be halved, that is the smallest multiple. It is true though if you further drop below 50 then, that it could drop to another multiple, say 33.3fps (100/3).



Likely a measuring error of the benchmarking tool if the framerate is jumping around if its fluxuating a lot and not a multiple of the refr hz.

That sounds right.

==>Lazn

 

[fastcoke11]

Edit - Bah nevermind. I thought we were talking about the first lowering of framerates, which would be worse if it was cut to 1/3 or 1/4 instead of 1/2, but if it goes down to 1/2, then to 1/3, then to 1/4 that's a lot better than it seemed.

 

[Lazn_Work]

The problem with the fact that it's not just halving the framerate is exactly what you said, it could be any whole number. That means that best case scenario is 1/2, and then it goes down to 1/3 refresh rate, 1/4 refresh rate, and etc. (Note that this means on a 120hz screen, it would be 60, 40, and 30 respectively). I don't know much about this, but if what you're saying is true, then the original poster could be considered as talking about the best case scenario when the system cannot achieve the same fps as refresh rate.

yep, this is why you want the highest refresh rate you can get.

eg: 120 goes to 60 40 30 24 etc
but 100 goes to 50 33.3 25 20 etc

==>Lazn

 

[Ugly_Jim]

wow. I can't believe this. Tearing annoys the shit out of me, and I use vsync whenever I can. I noticed it in single player doom3, too. Can anyone confirm or deny the points made in the original post?

 

[theelviscerator]

triple buffering sucks though b/c it slows down your input commands significantly

its horrible......

 

[haroldmeyer]

I will get an occasional "mouse lag" when I go around corners, my fps will still be 60fps,but my character will stop and then resume. This only happens every now and then, not enough to annoy me, just enough to notice. This mouse lag seems to happen most frequently when I first start the game (after loading a save), and then it just seems to quit as I go on further into the game.

 

[theelviscerator]

is it mouse lag? or hd access lag....you are hitting the hd for textures or the page file, check your hd lite at same time to see if this theory could be the culprit........

perhaps a raid zeros's high burst read negates the effect.....

 

[Ver]

Curious, is everyone using LCD's??

I've been using an LCD for a few years now and I never play my games without V-sync to avoid tearing. It's very noticable on LCD's. And refresh rates of your monitor don't really matter.

 

[burningrave101]

the problem occurs when you don't have an extremely high quality monitor that is able to do 100hz @ 1600x1200. I am currently limited to 72hz .... Even the new monitor I am looking at possibly picking up only does 85hz @ 1600x1200. 100mhz @ 1600x1200 translates to a pretty expensive display.

I have a Mitsubishi DP930SB and it will do 85Hz at 1600x1200 but you'd have to look into a 21" or 22" CRT if you wanted higher then that.

You dont need v-sync unless your playing an older game where the fps is really high. Your not going to be going much over 85 fps in todays games if you have the IQ maxed and playing at 1600x1200.

 

[burningrave101]

Curious, is everyone using LCD's??

I've been using an LCD for a few years now and I never play my games without V-sync to avoid tearing. It's very noticable on LCD's. And refresh rates of your monitor don't really matter.

You'll need v-sync if you have an LCD. LCD's response time isn't nearly as quick as a CRT's refresh rate. You will definitely notice tearing in games on an LCD without v-sync enabled.

I dont use v-sync on my 19" CRT and i havn't noticed visual tearing.

 

[Ugly_Jim]

Is it true the 6800 series cards do not support triple buffering in Doom 3?
Is it true the x800 series cards DO support triple buffering in Doom 3?

Has anyone answered this? Sorry if I'm being an idiot, but I can't figure it out.

 

[fastcoke11]

What about a DVI LCD screen? They don't have the digital tearing issue, right?

 

[Lazn_Work]

Is it true the 6800 series cards do not support triple buffering in Doom 3?
Is it true the x800 series cards DO support triple buffering in Doom 3?

Has anyone answered this? Sorry if I'm being an idiot, but I can't figure it out.

From what I can figure out, yes, but even with the x800 cards you have to do a registry edit (hack) to get tripple buffering to work.

==>Lazn