Horrible frame rates; Texture LOD Bias to blame??

[fuller556]

So I am having more problems with frame rate issues in this game than with any game I've ever tried to play on this system. I'm running with a quad-core AMD 3.0 GHz CPU, Radeon R7850 with 2 GB memory and 12 GB RAM on Windows 7 64-bit. This is the only game I've ever had poor performance on.

In troubleshooting, I've found that even anti-aliasing and V-Sync have no effect. Instead, I have to mess with the Texture LOD Bias setting. Depending on the game's mood, I either have to turn this all the way up, or all the way down. Case in point: I turned off V-Sync and enabled 8x anti-aliasing this morning; then I disabled AA and had absolutely no impact on performance. Then I turned the Texture LOD Bias all the way up from its default, and the game became playable. Well, 10 hours later, I fire the game back up and go straight in, and the frame rate is unplayable again! So I turned the Texture LOD Bias completely OFF, and the game smoothed right out. I'm not well-versed on graphical settings and don't know what this one does, but whatever it does, it's the only thing making the game playable, and it looks like I'll have to adjust it every time I start the game. This is very annoying, and now that the game has (supposedly) matured, bugs like this should already have been patched out. (Also, that nice little crash where you have to replace one of the AMD video driver files with one from an old version and put it in your Doom 3 BFG folder; yeah, that happened to me this morning, too).

So I'm just wondering if anyone else has had horrible frame rate issues, what they did to resolve it, and if this setting has affected any else's system. Would have to hear some more thoughts on this.

[motorsep]

Well, the problem is with AMD. Poor drivers = poor OpenGL performance. Other games more tha likely use DX instead of OpenGL.

Turn off Catalyst AI, see if that helps (in Catalyst settings, not in the game).

[fuller556]

I don't even have Catalyst Control Center installed; I only ever install the actual driver, not the CCC software.

[fuller556]

CCC tends to slow down all of my other games, though I do appreciate the response. I actually am using Version 13.9 (just installed it this past week). I'm actually finding now that the actual VALUE of LOD Texture Bias doesn't matter; just turning it up or down resolves the stuttering. Which means the setting is even more pointless than I thought. The problem had actually started at the default setting, which is the only reason I adjusted it to start with. Now it seems I literally only have to adjust it up or down a single notch to solve the whole problem. So I probably won't fool too much more with it, but id/Bethesda need to fix this permanently. I have absolutely zero problem with frame rates with every other game I own. Very weird.

[fuller556]

I agree, it's totally nuts. Never would have believed it if I hadn't seen it with my own eyes about 3 times now.

[motorsep]

That's why it makes sense to install full Catalyst.

[fuller556]

Eh, not worth it. I have slower performance in all of my other games with it installed, even if I don't change any settings. Anyway, I just finished The Lost Mission; as soon as I finish the Doom II expansion included with it, it's getting uninstalled anyway. I finished vanilla Doom 3 and Resurrection of Evil a long time ago. I thought BFG Edition would make a nice package with the plus of Steam integration, but it's poorly polished. I'm even getting cheated out of the achievement for completing The Lost Mission because it THINKS I opened the console, when in truth, I never opened it the entire time. So it disabled all achievements for the duration. I'm definitely glad I only spent $5 on this game because it just isn't put together well.

[motorsep]

It is a nice package, despite the fact that you have no clue about setting up your PC to work smoothly.

[Sharkfood]

Hey fuller-
Any quad-core processor + a Radeon 7850 should be CRUSHING this game, and it does.

Even a wimpy 6570 with 1GB vram will crush this game with maxed settings...

First red-flag I see in your post is this:
>> enabled 8x anti-aliasing this morning..

Well, that is your first problem... ramp down the AA as you have a single card. Use 2x or 4x, depending on your monitor.

Do the math: lets say you have a 1920x1080 resolution display. That means 2,073,600 bits per display... 4,147,200 with double-buffering of Doom 3.

Now, let's add 8x antialiasing, which is 8 more sample buffers. This amounts to 16,588,800 bits, or 2,073,600 bytes,, or better 2GB of vram, plus add more for double or triple buffering. So, you have already allocated your entire VRAM to just sample buffer space and this is besides whatever the game needs for texture vram (which if you use High or Ultra is another 256-512MB by itself).....

So your performance issues make sense. You are trying to cram 20lbs into a 10lb box. Ease off the AA settings. 8x or above AA is best suited to Crossfire where you have two 2GB cards to split the VRAM load per samples. This also explains why LOD changes help as this lightens the texture use of VRAM since it's all being allocated to sample buffer space..

Good luck!