There are a few reasons why I think this may the case. Mind you I'm only speculating here:

1) I believe the code base of CoD lives in the managed world, i.e. .NET and it makes unmanaged function calls to the DX API to render the graphics. This style of programming model is inherently a more memory intensive operation and slower (only slightly) as there's lots of storing of memory heaps and stacks and buffers going on. But it means more manageable code, no need to worry about memory leaks as much as unmanaged code and easier to update / modify.

2) We're dealing with a flight simulation that needs to create a land mass which is not only accurate but vast as seen from the sky, this means more memory is needed than the average game to store the environment. On top of all that, you have textures and buffers (pixel, vertex, shaders etc.), and 3D models with a higher than average poly count.

3) Optimization. I don't think CoD is properly optimized, hence why it's going through a complete rewrite at the moment.

So what? That doesn't change the fact that there are games that use over 2gb of vram - and cod is one of those titles.

Also keep in mind that the game is using a deferred rendering pipeline. That means that the game is rendering to multiple buffers - all of which take up space that is directly tied to resolution.

Agreed, which makes it more memory intensive than other games or even other sims. I've seen it in Evga Precision peak at 2.5 Gb vram! That is exceptionally high and most likely a result of #3 not so much #2.

Name one that uses 2.5 gb vram with no AA or AF applied. Crysis2 and BF3 use 1-1.5 gB with 16x AA and 16x AF and there is no sim that uses 2.5 Gb with no AA and AF. CoD uses so much, not because it is so complex, it is because it is not optimized. That is why they are redoing the graphics engine.

BTW, I'm not being negative here, I'm being positive. When this is optimized there will be hope for those with less than 3 Gb ram.

The discussion regards Vsync and Triple Buffering interested me based on the frame rate integer jumps that Ataros mentioned.

I have always had Vsync enabled and triple Buffers set but decided to test a MP session with Vsync disabled and Triple buffers Off. Apart from the screen tearing, I was acheivineg 80+ fps at altitude and game play was much better even in the hotspots were FPS sink badly - it seemed much smoother even when fps went below 30.

I am torn wether to put up with the screen tearing (which isn't so bad that its unplayable with headtracking) or go back to Vsync capping at 60hz:confused:

EDIT: After writing this I did a bit of googling and found this interesting article regards Vsync/Triple Buffering and the advantages/disadvantages.


http://www.tweakguides.com/Graphics_9.html


This link explains how Triple Buffering works - why it isn't supported in DirectX3D, etc.

http://www.anandtech.com/show/2794/1

I agree with that tweak guide. It's comes down to personal preference. We've all got different hardware and its a matter of trying different settings.

I have less than 3 gigs of vram and have never had a CTD, or Launcher exe problem, or frame rate issue. It tells me the code isn't all bad, but an optimization/rewrite of the code it still urgently required. Hopefully the next patch will fix most of the performance issues, and the developers can put more resources in fixing the game play issues.

I think he must know what he is talking about :)

However there are many different opinions and discussions on other forums like guru3D, etc. Some say only OGL lines of code are present inside the drivers.

Another opinion is that an application itself must have triple buffering enabled and some applications enable it by default when a user switches vsynk on inside the app (but not in drivers). Some apps like Left for Dead and BF3 have tripple buffering as a separate checkbox in settings.

We do not know how CloD is programmed and need to benchmark it with various settings to find out. IIRC when I switched vsync ON in drivers I had some issues. Maybe ingame CloD vsync uses TB.

ATI Catalyst still lists triple buffering inside OGL section only. I run vsynk off to be on a safe side. Having TrackIR smoothing set to max helps me to avoid tearing. It still happens but on very rare occasions. Reducing settings also helps with it.

For NV users to be on a safe side I would install D3D Overrider to force triple bufering ON and test it. It is free :)
Download and install recent RivaTuner, find the D3D Overrider executable inside the install folder and copy it somewhere. you can now uninstall RivaTuner. D3D Overrider does not require RivaTuner to run.

You are lucky or you have a lot turned down. I have nearly the same rig as you with more ram and 2x gtx 580 3 gb and it stutters and looks bad with no AA or AF even with decent fps. CoD uses way more video ram than you have so you must have it turned way down or fly over water all the time. It uses upwards of 2.5 gb vram and I have a few things turned down and that is with no AA or AF remember. Turn those on and it would be a slide show for everyone, that's for sure. That is proof of a need for optimization. I look forward to the next patch and stutter free flying.


I also have had a couple of CTD's and the launcher doesn't respond sometimes when you change settings and it reboots the game. BTW, why does the game have to restart whenever you change video settings?

EDIT: "On the other hand, locating a memory leak can take many long months of dedicated work by some extremely qualified programmers." -Luthier today. There well may be memory leaks which I had suspected.

Thanks Ataros. Using the QM 'Intercept Bombers - London' by starting with the comabat scenario and then flying low alt over Tower Bridge/Parliament I tried the following:-

1. Vysinc Disabled. (Pre render frames=1 NVidia CP)

2. Vysinc enabled. (Pre render frames=1 NVidia CP)

3. Vsync Enabled + (Triple Buffering - Pre Render Frames =3 Nvidea CP)

4. Vsync Enabled + (Triple Buffering Forced D3D Overrider).


I expected to see differences in performance but didn't except for Screen Tearining in 1 above. In fact, just having Vsync enabled in 2 above seemed just as good as 3, 4, and 1 but without the screen tearing....:confused: