Not sure if it is a driver issue but I had strange performance issues with using in game AA on a system with a GTX 770. My only solution for running the game at a smooth 60 FPS with AA is to use SweetFX 2.0 and use the SMAA option. It is not a perfect AA solution but it is better than nothing.

Same applies to Quake 4 and possibly Prey, might have something to do with the engine with modern hardware or something to that effect.

Strange how?
I haven't tried SMAA. Do you find it looks better than Doom 3's native x4 AA?

The driver I'm using is something like 347.xx (not on that computer right now to check), on WinXP.

BTW, a reference point with a 2004-era graphics card from AnandTech...
GeForce 6800 Ultra Extreme (silly name), at 1600x1200, Ultra quality, x4 AA, runs the game at about 40fps.
GTX 750 non-TI should be multiple times faster.

bakcom wrote:

Strange how? I haven't tried SMAA. Do you find it looks better than Doom 3's native x4 AA? […]
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Strange how?
I haven't tried SMAA. Do you find it looks better than Doom 3's native x4 AA?

The driver I'm using is something like 347.xx (not on that computer right now to check), on WinXP.

BTW, a reference point with a 2004-era graphics card from AnandTech...
GeForce 6800 Ultra Extreme (silly name), at 1600x1200, Ultra quality, x4 AA, runs the game at about 40fps.
GTX 750 non-TI should be multiple times faster.

When I mean strange, I mean when combat occurred on my end the game would slow down, not lag or stutter, literally slow down like bullet time in Max Payne. It only happened when I used AA in the game or forced it in my GPU control panel.

SMAA is good, but it does not beat Doom 3's native AA since it is more of a filter than an image enhancement. There's still aliasing but it at least gets ride of the more jagged stuff.

I tried this with GTX 550 SLI at 1920x1080 with all settings at max, including x16 AA. I get 45-50 fps when looking at the stairs before moving. It doesn't drop below that while walking towards the door, but when I turn around it drops to about 35 when I look at the guy on the bench.

SpooferJahk wrote:

When I mean strange, I mean when combat occurred on my end the game would slow down, not lag or stutter, literally slow down like bullet time in Max Payne.

Perhaps you set com_fixedTic to 1?

Errius wrote:

I tried this with GTX 550 SLI

Unusual setup. What would you say it is equivalent to in a single card?

Dunno, but this setup scores 5101 in 3DMark 11. (2933 for single card.)

bakcom wrote:

SpooferJahk wrote:

When I mean strange, I mean when combat occurred on my end the game would slow down, not lag or stutter, literally slow down like bullet time in Max Payne.

Perhaps you set com_fixedTic to 1?

This is with that option on, even with it off that causes problems in other ways like odd stuttering on my end.

Errius wrote:

Dunno, but this setup scores 5101 in 3DMark 11. (2933 for single card.)

The fps you get is with vsync on? I should check with Fraps what's going on in more detail rather than rely on the game's counter. The 50fps I get (with x4 AA) is actually an odd figure for standing still in the game with vsync on. If correct, it would imply a rate that changes between 30 and 60fps in a regular pattern.

SpooferJahk wrote:

This is with that option on, even with it off that causes problems in other ways like odd stuttering on my end.

By default I had regular stuttering/hiccups, quite an odd bug that apparently many experience. Setting com_fixedTic to 1 fixes or at least improves it, but causes motion slowdowns when the frame rate is lower than 60. The best solution I found, instead, is setting com_preciseTic to 0.

All settings on "yes" including v-sync. I have brightness and gamma to the max, don't know if that makes a difference.

Runs fine here with 4x AA, (I find anything over that too blurry) I am using a GTX 1070 though. The only time it goes under 60 is when I noclip out of the map and look at everything.

AAx4 is generally fine here as well. It's the x8 and x16 modes that are too slow.

There are a few spots where x4 drops down to consistent 30fps, but it's not common. In one spot I disabled vsync to see the effect, and the result was about 50 fps. I guess frames there draw consistently a few ms too long for 60Hz.

I didn't find x8/x16 blurry, maybe something renders differently on your setup? You can try changing the game's texture mipmap bias by setting image_lodbias to small negative values. Maybe -0.5 or -1. You can also try forcing it in the driver using Nvidia Inspector or similar.

Nah, just in general I don't like using AA over 4.

@ bakcom - Which version of D3 are you running? On modern rigs v1 can confer a 10-15% (or more) frame boost over the 1.2 and 1.3+ patches. Thread on the ongoing D3 benchmark extravaganza here:
Doom 3 timedemo shootout with period correct hardware.

Thanks. It was with the latest v1.31. Haven't tried older versions, but even if faster I would want the fixes.
Performance could be better in parts, but generally it was fine.

I have not had any issues with Doom 3, but I am also running a GTX 1080. Occasionally I saw some stuttering but that does not seem to be an issue after the Anniversary update.

Turn on FXAA and see if that fixes the issue. For some bizarre reason, antialiasing causes major frame drops unless you have FXAA enabled, at which point it will apply all of those settings while still maintaining a smooth 60fps. At least for me, anyways. Dunno about the others but it's worth a shot.

Errius wrote:

I tried this with GTX 550 SLI at 1920x1080 with all settings at max, including x16 AA. I get 45-50 fps when looking at the stairs before moving. It doesn't drop below that while walking towards the door, but when I turn around it drops to about 35 when I look at the guy on the bench.

1920x1080 with all that AA does need quite a bit of grunt. Those settings brought the 6800GT's and X1950's to their knees, even at much lower resolutions.

I played through Doom III again a few years ago on a GTX760 with a decent overclock and an IvyBridge i5. It held 60fps without a problem, averaging around 116fps in timedemo, but that was without AA. Factor in 30% fps reduction for the AA, and another 30% for the 750Ti being slower than the 760 by quite a margin, and it seems you're getting about the right framerate. Play it without AA! 🤣

gameragodzilla wrote:

Turn on FXAA and see if that fixes the issue. For some bizarre reason, antialiasing causes major frame drops unless you have FXAA enabled

It's a type of antialiasing that's less taxing than the default MSAA. I'm not sure I like it, but I'll have a look again the next time.

Iris030380 wrote:

It held 60fps without a problem, averaging around 116fps in timedemo, but that was without AA. Factor in 30% fps reduction for the AA, and another 30% for the 750Ti being slower than the 760 by quite a margin, and it seems you're getting about the right framerate.

There could be other bottlenecks in addition. Even in games older and simpler than Doom 3 you don't always get 60FPS with AA. For example, Max Payne (1) at 1440x1080, which I played recently.