ATI Radeon R600

R600 Technical Aspects 2

Custom Filter Anti-Aliasing

The R600 range have a new type of Anti-Aliasing called Custom Filter Anti-Aliasing (CFAA), featuring edge detect, narrow tent & wide tent filters to reduce texture shimming. Along with higher compression ratios for Multi-Sample Anti-Aliasing (MSAA).
The way CFAA works is different to the standard MSAA in that instead of using a box/grid to divide the screen and having samples taken from inside these boxes it uses an array of larger circular areas which allow overlapping and also better coverage.

CFAA supports programmable sample patterns & filters. It is also upgradable with driver updates which is one of the reasons why we could see some improvements in performance with each driver update.

It's worth noting that ATi's new implementation CFAA has quite a few good points to it (such as speeding up per-pixel samples on limited memory), but this technique could lead to actually a blurring of the image, rather than a sharpening and reducing jaggies. nVidia's implementation here shows it's strengths with a more precise implementation in it's QAA.


This is another advance in 3D hardware that was developed on the xbox360's GPU. Tesselation makes it easier for developers by creating a means of hardware smoothing. This means developers can have something which might look coarse and even not very detailed, the GPU will then do most of the work. The end product looks much more detailed and life-like. This also obviously works for terrains and helps in animation, converting primitive data into something beautifull.

512-bit memory interface

As mentioned earlier the Radeon 2900XT has the worlds first 512-bit memory interface, giving it a huge bandwidth boost. When comparing it to the X1900XT for example the 2900XT has over 2x the bandwidth (X1900XT 46.4GB/second)

The ATI Radeon™ HD 2900 Memory Controller
  • Worlds first 512-bit memory interface
  • Over 100GB/sec memory bandwidth
  • 512-bit 8-channel GDDR3/4 memory interface
  • Ring Bus Memory Controller
    • Fully distributed design with 1024-bit internal ring bus for memory reads and writes
    • Optimized for high performance HDR (High Dynamic Range) rendering at high display resolutions

ATI have talked about the ring-bus architecture before, but this time they've given their card 512 bits to play with - a worlds first. The ring-bus is a bi-directional approach to memory architecture meaning the data gets to where it needs to go by the shortest route, making it highly efficient. It's all about bandwidth here, and that's what GPU's really benefit from.

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Most Recent Comments

16-05-2007, 14:00:16


The long awaited and hugely anticipated ATI card is finally here. We have been given access to information and media documenting ATI's first DirectX10 graphics card. The technical specifications look promising, with some features never before seen on a GPU, making these cards innovative and one of a kind.

This article is designed to run through a little bit of the technical information without confusing the hell out of you. It is a short and sweet introduction into r600 and it's architecture and is meant to cover it in an understandable way.

I've just finished my first article (with the help of Kempez) for OC3D. I hope people find it interesting and informative.

Please Discuss Quote

16-05-2007, 14:03:07

Great work mate. Nice and simple and easy to understand while getting the key points across

Hope everyone enjoys reading it Quote

16-05-2007, 15:00:09

Great article, cant wait for the review.


16-05-2007, 16:09:29

Good work on your first write up matey!

Once again I cannot wait for the view, equk.. are you doing the review too?Quote

16-05-2007, 16:32:16

No I'm doing that Quote

16-05-2007, 16:35:56

Originally Posted by name='Kempez'
No I'm doing that

Suprise suprise.. Kemp always gets his hands on the best stuff!

Good on ya mate!Quote

16-05-2007, 16:37:28

top banana!Quote

16-05-2007, 17:57:19

PP Mguire
Well written review. I enjoyed reading it.Quote

16-05-2007, 18:23:50

A good read, seems like ATI/AMD are really pushing the envelope with sound, Avivo etc.

Two things caught my eye though, at the bottom of page 4 it says.

ATI have talked about the ring-bus architecture before, but this time they've given their card 512mb to play with - a worlds first.

I think you mean 512 bits, maybe?

At the top of page 5 it says.

However if your an HTPC enthusiast you are going to have a decent discrete GPU for your audio so I see the 5.1 sound card as a pretty neat if not slightly useless addition to the 2X00 series.

Do you maybe mean discrete sound card?

I look forward to your next article. Quote

16-05-2007, 18:36:31

Yep my bad - should be bit and APU (probably just sound card is better)Quote

16-05-2007, 19:51:18

Thanks for the feedback

I think the onchip sound is good & means ATI can market it a bit better, saying it's one of a kind, while also gaining conformity for both protected content and also Windows Vista Premium Logo.

Originally Posted by name='equk'
Because the video and sound are not seperated the card conforms to the protected content output path, which also makes it compliant with Windows Vista Premium Logo requirements.
Originally Posted by name='kempez'
However if your an HTPC enthusiast you are going to have a decent discrete GPU for your audio so I see the 5.1 sound card as a pretty neat if not slightly useless addition to the 2X00 series.
Altho I agree with what kempez has said, most people do already have a dedicated soundcard, all the on-chip one means tho is you don't need loads of wires and it can connect direct to new HDMI tv's.Quote

16-05-2007, 20:04:39

Ye I get where you're going but it's not a premium audio chip which is a little disappointingQuote

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