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jimmyjames123
04-17-04, 02:06 AM
Why is NVDA still using an impractical 8x AA setting with the 6800 Ultra? Does anyone have any insight into why they chose to use a MS+SS mix for their 8xAA, which causes a huge performance drop and essentially renders this mode useless? Does this 8xAA method even save transistors or complexity for the design?

I am of the opinion that up to 4xAA and 16xAF seems to be a good area of focus, but still NVDA has essentially rendered their 8xAA mode useless because of the massive performance drop. In addition, some reviews will test the 8xAA mode, and this makes the 6800 Ultra look exceptionally poor, especially compared to it's 4xAA performance.

How easy or difficult would this be to fix/remedy/improve?

CaiNaM
04-17-04, 02:18 AM
curious.... what game and at what resolution are you experiencing this "issue"?

jAkUp
04-17-04, 02:35 AM
Yea, im a little dissapointed with the 8xaa also... Oh well, I dont really plan on using AA that high though, since I'm a bigger fan of higher res rather than AA.

jimmyjames123
04-17-04, 02:40 AM
I agree that for this current generation it seems to be a reasonably good move for NVDA to concentrate on very high speed up to 4xAA and 16xAF at high resolutions. The 6800 Ultra delivers in spades up to these settings, according to the reviews. However, it looks as if the 8xAA was a complete afterthought. I am trying to get a better understanding of why NVDA would choose to set up 8xAA in the manner that they did. Surely there must be a more efficient way of doing 8xAA! Maybe the 8xAA is there as a checkbox feature, but is not really meant to be a practical feature, so NVDA didn't put too much work into it.

AthlonXP1800
04-17-04, 12:43 PM
Well you never know whether or not that 8xAA has huge performance hit dued to inmature driver, maybe in next few months 8xAA performance could improve alots, it probably very useful with old games at 1024x768.

zakelwe
04-17-04, 12:49 PM
Maybe they will improve it, maybe they will not, but the sweet spot for me is the 6800's ability to do 1280x1024 4XAA.

I play most games at 1024x768 - 1280x1024 with no AA and some AF but the 6800 will give me 4xAA and much higher frame rates and I might be able to go 1600x1200 in a lot of cases.

That's a big step up for me.

You're not doing a bad upgrade if you can go up one level or resolution, one level or more of AA/AF and have faster framerates. You will be impressed.

This is why a lot of people who went from GF4 to FX series were not impressed if they got 5200/5600/5700nu

Regards

Andy

hell_of_doom
04-17-04, 02:05 PM
AS far I know r420 will have AA8x and what NV40 offer right now in term of IQ is going to be a joke...just wait :clap:

jimmyjames123
04-17-04, 02:12 PM
What do you mean when you say "a joke"? I guess all the current Radeon owners better start throwing away their cards, huh? :D My goodness, what a fanboy!

So what are you doing here at NVNews other than spreading FUD?

hell_of_doom
04-17-04, 02:20 PM
What do you mean when you say "a joke"? I guess all the current Radeon owners better start throwing away their cards, huh? :D My goodness, what a fanboy!

So what are you doing here at NVNews other than spreading FUD?

Yeah you could tell IQ on current ATI cards will look like joke... :lol2:

jimmyjames123
04-17-04, 02:22 PM
Better bring out the wastebaskets then, Radeon 9xxx owners, according to h_o_d :lol2:

Ruined
04-17-04, 02:35 PM
rage3d must be down

particleman
04-17-04, 03:06 PM
I actually like Supersampling, in fact I wish there were pure (non-hybrid) supersampling modes available in the control panel. I've noticed that pure supersampling modes exhibit fewer bugs in older games, and they do antialias alpha textures. I like the 8XS mode, sure you can criticize it's performance hit, but it provides great IQ and does alpha textures, the 8XS mode is very useful for older games that use a lot of alpha textures.

I tend to not use modes above 4x anyways.

StealthHawk
04-18-04, 02:30 AM
Well you never know whether or not that 8xAA has huge performance hit dued to inmature driver, maybe in next few months 8xAA performance could improve alots, it probably very useful with old games at 1024x768.

Of course we know why there is a big performance hit. Because the Super Sampling portion of 8xS is using 4x Super Sampling! You can see the same basic performance trend when using 8xS on a NV3x or even on a NV2x. The only thing that is going to change performance is if NVIDIA exposes a better hybrid mode that offers similar IQ instead of 8xS...which I believe they actually have. Why this mode isn't in the control panel instead of 8xS is beyond me.

edit: duh, nevermind. Obviously they are using 8xS because the other mode is D3D only.

particleman
04-18-04, 02:58 AM
BTW why isn't that we have never seen 4XS, 6XS, or 4X Supersampling work in OpenGL? Is there any technical reason why they can't do it?

XanderF
04-18-04, 03:02 AM
I like the 8XS mode, sure you can criticize it's performance hit, but it provides great IQ and does alpha textures, the 8XS mode is very useful for older games that use a lot of alpha textures.

Yeah, I mean, c'mon. Who was it - Anand's? Toms? Ran Far Cry at 1280x1024 with 8xAA. Got something like 24fps.

Okay, so that's unplayable.

At 1280x1024.

In FAR CRY!!!

On the 6800u, 8xAA is going to be usable on DAMN NEAR every game currently out! What are you bitching about?

As to why it was implemented - actually, it probably was to save space. Super-sampling is pretty cheap to do, transistor-wise. Multi-sampling isn't. Hence, even on the 6800, nVidia is sticking with a limit of 4xMSAA. Since ATI will obviously be offering higher FSAA modes than that (already are), nVidia uses combined MSAA + SSAA algorithms to compete.

And, honestly, why not? We all know what SSAA does for texture 'crawl' and alpha-textures. 4xMSAA already looks pretty damn good, combining that with SSAA, too, both for its smoothing capability and ability to fix so much more on the image MSAA just can't touch?

Sounds like a good idea to me!

Deathlike2
04-18-04, 03:07 AM
Super-sampling is pretty cheap to do, transistor-wise.

True, but it's slow.
2X SSAA cuts fillrate in half (1/2)...
4X SSAA cuts fillrate by a quarter (1/4)

Sounds like a good idea to me!

I don't see how this is beneficial... I can only see it useful for old games... and ONLY old games.

StealthHawk
04-18-04, 03:10 AM
BTW why isn't that we have never seen 4XS, 6XS, or 4X Supersampling work in OpenGL? Is there any technical reason why they can't do it?

Supposedly Super Sampling can only be done in OGL when the scale factor is equal for both vertical and horizontal scale. 4xS for example, uses a Super Sampling component of 1x2. 1 and 2 obviously not being equal, apparently this kind of Super Sampling cannot be done in OGL. 6x uses 1.5x1, so same story here.

There is no reason why 4x Super Sampling cannot be done in OGL. In fact, that is the Super Sampling component of 8xS, which is available in OGL.

XanderF
04-18-04, 03:11 AM
But define 'old games'!

As I mentioned, one review showed it hitting 24fps in FAR CRY!!! That's *almost* playable levels (well, about half, actually), and tell me there is a game on the market a fraction as demanding as Far Cry is.

XanderF
04-18-04, 03:17 AM
Okay, my bad.

I think this was the page I was thinking of (http://www.tomshardware.com/graphic/20040414/geforce_6800-43.html).

Note that is is 22fps, and it's UT2K4.

But....running at 1600x1200!!

Especially given the nature of SSAA, you'll see a substantially reduced performance hit by playing at normal resolutions. I'd bet the numbers would be almost double that playing at 1280x1024.

NightFire
04-18-04, 08:44 AM
But remember, it's *rumored* that the early reviewers may have gotten a clocked down version using A1 silicon. The final retail may be as fast as 475 Mhz, and bear in mind that Nvidia's partners *may* increase the clock speed.
All wild speculation, but you never know.