Quincunx AA vs. 4xAA

[AirRaid]

What are your views on this? I know Quincux blurs textures slightly, giving (only slightly) poorer image quality overall, but it does perform a lot better than 4x does.... Just wondering, cos I get like an extra 10-20 fps in Tenebrae with Quincunx rather than 4x.

[Crix]

I was wondering about this also. Yeah, 4X is really slow.

I know tomshardware.com had a good article a long time ago comparing all the AA's including shots from Quake3 comparing jaggies and textures.

[GS-1719]

I don't allow anything to pass my eyes without Quincunx. There is very little performance cost too.

[Katarhyne]

You'll find that Quincunx and 2x have an extremely similar performance requirement. There's a reason - they're the same thing. The only difference is that Quincunx applies a blur filter over the whole scene. You can get the same effect by playing on a TV. Essentially, all Quincunx does is lower the dot-pitch of your monitor. Congaturations, you've just been fooled by Nvidia.

If you have a high-quality monitor, using Quincunx makes you a very big fool.

[PlayfulPuppy]

Katarhyne said:

You'll find that Quincunx and 2x have an extremely similar performance requirement. There's a reason - they're the same thing. The only difference is that Quincunx applies a blur filter over the whole scene. You can get the same effect by playing on a TV. Essentially, all Quincunx does is lower the dot-pitch of your monitor. Congaturations, you've just been fooled by Nvidia.

If you have a high-quality monitor, using Quincunx makes you a very big fool.

So, if I take a screenshot while the game is running on my TV, the screenshot will look smooth?

Like, wow.

Please note scarcasm and do math. :)

[Katarhyne]

Of course not. I realize you're being sarcastic, but...

For the benefit of those who think that's the way it works - it's not. In fact, there are some other very interesting issues that spring up around this very issue. But I won't get into them. I'll merely say that the reason you don't see the blurring on a TV-out screenshot is because a screenshot is literally a snapshot of the output that the video card is sending to the RAMDAC (NOT what the video card is sending to the monitor, thus anything that happens after the RAMDAC, like 3dfx's 16-bit post filter, and some other effects Nvidia does with some FSAA modes including '4x9' mode, won't show up in a screenshot). So, if the image is blurred by the output device, it obviously won't show up in a screenshot.

[Radea`]

Yeah, as Katarhyne said, all QuinCunx AA is 2X FSAA with a blur filter to reduce noticable aliased textures/edges/whatever. To counteract the bluring you can enable AF I guess, but since its using a different algorithm than ATI cards (ATI cards only apply AF on whats needed (adaptive), which is one of the reasons for the very good AF performance, and 16X AF rivals 8X on nVIDIA's) the nVIDIA card falls to the ground in performance.

Another reason why I hate QuinCunx... nVIDIA cards by default (its about time to admit it) have a lower LOD than ATI cards. Applying a blurring filter over a already multi-sampled AA image before being sent to the inferior RAMDAC's, your in for a shit IQ treat :). I'd just use regular 2X FSAA, as then you dont have *as bad* of an IQ *or* performance problem if your using AF.