Anti-Aliasing results in HUGE drop in performance?

I have an ATI mobility 2600 HD, which I had expected to play Half Life 2 at max settings at 1280x800 with 2x AA. I expected some drop in performance, but not one where I had 100FPS without AA, but <30FPS with AA. Is there some quality control for AA that I'm not aware of?

I'm running Vista 32-bit, with Intel Core2 Duo T5550 (which isn't the best), and 3GB of RAM. Also, I have upgraded to the latest ATI display drivers, installed with mobility modder.

 

The answer to that is...

Yes. In general, AA tends to hit performance hard. Very hard.

 

I'll do a quick run through HL2: Lost Coast and post my results, max with/out 2x AA @ 1280x800.

EDIT1: 69fps avg at 500/400.

EDIT2: 44fps avg w/ 2x AA

EDIT3: 43 fps avg w/ 4x AA

EDIT4: 68 fps agv w/ 6x AA (though I believe there's still a glitch where 6x doesn't work, as evident by fps). Will check more on this some other time/will compare levels of AA vs fps.

 

Didn't ati's 2600 series cards have a problem handling Anti-Aliasing?

 

^^ If that's true, I wish I had known that before I purchased this laptop... >.<

 

I'm pretty sure thats the case, can't remember where I read it, but I know there was a comparison done vs nvidia cards and ati cards fps just plummeted when using Anti-Aliasing. Only other thing I can think of is maybe try some other drivers. Besides the drivers and the ati card, it could also be your cpu. The half life games are pretty cpu demanding, but I would still think you could get better than 30 fps.

 

You could always try changing the type of AA, ie. box, narrow-tent, wide-tent, etc.

And weaker level mobile/desktop cards will struggle with AA since that's not what they're built for. They're built for mediocre gaming at a decent price.

 

AA hits any video card pretty hard. Even the might 8800M GTS with AA on will lose a bunch of FPS. Hope this helps. God Bless

 

Try changing your drivers.

Ive had issues with AA and AF which turned out to be the drivers. If i put my AA higher than 4x it will half the fps straight away.

If i put my AF too high it will crash the game after 10mins.

 

Normally GPUs have some dedicated hardware to assist in applying AA. In the case of the R600 (HD 2900) and presumably it's lower-end derivatives, ATI cut out that hardware and decided to use shader programs instead. Obviously this puts a greater load on the shaders as well as the internal interconnects having to shuffle things back to the shaders instead of just going downstream. This may have been acceptable on the HD 2900, but no doubt isn't optimal for lower-end GPUs.

The newer RV770 Radeon 48xx series have dedicated AA hardware added back and also have significantly more shader power, so either way, doesn't have as much of a AA performance drop.

 

Yes, my HD 2600 is similar to that as well. Even when overclocked it isn't always perfectly smooth, so is probably dipping below 30fps at some points. It's definately very playable, but after getting used to how smooth it is without AA (after recently finishing the game, I never noticed any low fps), I chose to play without.

AA was definately a weakness of the HD 2000 series.

 

AA is a weakness of all Midrange cards, not just yours man

 

I guess I'll just play it without AA...

But before that, I would like to change the drivers one more time. Does it follow the same process as on a desktop? That is, uninstall driver, run driver cleaner, then get the new driver on?

 

With the new ATI ones, you don't even need to uninstall your previous ones, you can just upgrade.

 

Source Games fare pretty well even with the AA enabled, but try upping it in games like cod4 or crysis and you'll almost hear your card whimper...

 

That's the one I'm using right now, and I was thinking of changing the drivers to something like omega drivers.

 

I play HL2, EP1 and 2 with native, all maxed, 16x AF/16x AA. It doesn't really effect the GTS, getting an average of 60-100FPS...

But I agree, I can only play CoD4 with 2xAA maxed, anymore results in 30 or so FPS, which is a bit too low for a game like that.

 

That's because your card is about 3 times as strong as the HD2600 DDR2. You also have 4x the number of ROPS = less performance hit when using AA.

 

I wasn't trying to brag, just making the comments that some cards can handle HL2 with AA. To brag, I would need to be able to even touch AA with Crysis... which is a no bueno.

 

i think the hd 2600 should be able to handle crysis fluently at max with at least some anti aliasing.

hah. brain poop. half life 2, not crysis.

 

Cant you just up the resolution instead of adding AA to it and it will be less of a performance hit?

 

Thats good, but HL is probably the best optimized pc game I've ever played, every other game will have far greater drops in performance.

 

Yes... Yes you can/should...

 

Okay, the Lost Coast results look about right.

Vanilla HL2 should be fine with AA even on a DDR2 2600. Hell, I can turn AA on in that game on my 8400M GS.

If we're talking about Episode Two, on the other hand, it wouldn't surprise me if AA didn't work so well.

Still, 2xAA shouldn't massacre framerate THAT bad. It should halve it at most at 1280x800, not knock it down from 100+ to 30.