R520 can do HDR with AA

[Graphicmaniac]

looking these pics:

http://www.techpowerup.com/reviews/ATI/R5XX/1

[Ady]

and nvidia said it couldn't be done. Looks like the ATi engineers could teach the nvidia boys a lesson or two. ;)

I can't wait to try it out. :D :cool:

[nutball]

That wasn't *quite* what NVIDIA said (believe it or not adding together floating-point numbers isn't *that* hard)... they said it couldn't be done whilst maintaining decent performance.

Until the performance of HDR+AA on X1x00 is clear from reviews (cf. PR hype) we don't know if this is just a tick-box feature (like we've seen a number of in the past from both companies), or whether it's actually usable.

[Ady]

Yeah I think this is the interview where they talked about it...

http://www.bit-tech.net/bits/2005/07/11/nvidia_rsx_interview/3.html

[|MaguS|]

Guess you ignored that DOD:S has HDR and both ATI and Nvidia can do AA in it. AA can be done in HDR, It just depends on the method its implemented...

[zer0]

can a X1800 run farcry 1.3 with HDR & AA on?

[T-Spoon]

can a X1800 run farcry 1.3 with HDR & AA on?

Who knows... maybe it explains why Far Cry was patched to 1.32 and included this line in the patchnotes:

"A problem with the ShaderModel 3.0 has been fixed, that lead to graphic problems on the new ATI cards"

Another game that also uses HDR and was patched to support ATi's next gen is Earth 2160. It could be that both games were patched to support HDR + AA on ATi hardware.

[SH64]

Its still uncertain if they meant AA with OpenEXR or just the other types of HDR rendering like I16 etc..
if thats what they meant then both nV & ATi gpus can do AA in games like DoD:S & rthdribl demo & if they meant AA on all HDR methods then thats going to be a big + for the X1800 series!

[Ady]

can a X1800 run farcry 1.3 with HDR & AA on?


Yes, it looks like it will be able to.

Guess you ignored that DOD:S has HDR and both ATI and Nvidia can do AA in it. AA can be done in HDR, It just depends on the method its implemented...

Not ignored. It just wasn't what we were talking about. It's a different thing as you mentioned.

[AthlonXP1800]

Guess you ignored that DOD:S has HDR and both ATI and Nvidia can do AA in it. AA can be done in HDR, It just depends on the method its implemented...

Yeah and dont forget about long... Lost Coast. :p

[T-Spoon]

Its still uncertain if they meant AA with OpenEXR or just the other types of HDR rendering like I16 etc..
if thats what they meant then both nV & ATi gpus can do AA in games like DoD:S & rthdribl demo & if they meant AA on all HDR methods then thats going to be a big + for the X1800 series!

According to the Sell sheets:

The X1800 supports three different HDR modes (compared to NVIDIAs 1 format) for ultimate flexibility:
- 64-bit Floating Point for Maximum Range
- 64-bit Integer for Maximum Precision
- 10:10:10:2 (FP10) for Maximum speed
- All Support Blending And Anti-Aliasing (exclusive ATI advantage).

So it looks like all modes support AA.

[msxyz]

Nvidia supports both FP16 HDR and I16 "HiLo". 16bit HiLo has been available since GeForce3 days (though only under OpenGL and with limited functionality, to my knowledge) and there were even a couple of demos shown back in the day.

It's clear that the original post refers to HDR involving FP16 blending which cannot be done while using multisampling AA.

There is not a single algorithm for HDR. HDR itself is a vague term encompassing all that processes that simulate the human eye response.

[toxikneedle]

AA + HDR...... bring on the lag.

[Nutty]

The current problem is that NV doesn't do AA on floating point buffers. It doesn't mean you cant do AA, you just have to do it yourself in a pixel shader. You can still achieve the same result, but the hardware is not built todo it automatically. This is probably one thing you'll see in the next NV refresh.

"The X1800 supports three different HDR modes (compared to NVIDIAs 1 format)"

I've never heard so much bull****. NV has more than 1 HDR format.. Or how the hell do you explain RTHDRIBL running with float buffers and DOD:Source running with integer buffers ?

[anzak]

I've never heard so much bull****. NV has more than 1 HDR format.. Or how the hell do you explain RTHDRIBL running with float buffers and DOS:Source running with integer buffers ?

Yeah, also look at how they listed 12x temporal as their highest MSAA mode. 12x temporal is really two different 6xAA frames alternating and doesn't look near as good as nvidia's 8xS.

http://www.techpowerup.com/reviews/ATI/R5XX/images/X1800-4.jpg

[Subtestube]

HDR itself is a vague term encompassing all that processes that simulate the human eye response.

Erm... that's not quite true - exposure control is the thing that simulates the response to different levels of light. All HDR is is rendering internally at a higher precision, and allowing values outside of 0.0-1.0 during the rendering pipeline, so that when blurs, blooms, and all other kinds of post-processing are applied, dark areas go to black where they should and light areas don't go a nasty grey (It also prevents banding in excessively dark/light places by clamping the maximums at a sensible place - in concert with exposure control you get colours in dark areas when you should, and in light areas, when you should). Basically it allows you to maintain a proper distribution of colour without losing precision during the rendering pipeline, which is essential if you want to do proper post processing. It's true that to do exposure control properly, you do need some kind of HDR, otherwise you need to actually change what you're rendering at each stage, rather than just letting the standard pipeline sort it out.

Check this out - it explains it better than I do: http://en.wikipedia.org/wiki/High_dynamic_range_rendering

[maddbomber83]

http://www.bit-tech.net/preview/hardware/brightside_hdr_edr/2.html

The explained it all to me perty good. I want one of those tvs too.

[msxyz]

Well, I made an oversemplified statement. I know that rendering at a higher precision prevents the extreme tones to be clamped and the whole light range to be compressed.

But there are other way to obtain the same effect, ie rendering the scene twice with two different light settings and combining them together with a proper transfer function.

The point is that claiming it is (or isn't) possible to combine AA and HDR is a meaningless statement alone if we don't know what algorithm is used.

[Subtestube]

Fair call - you're quite right in that statement.

Apologies if I sounded disparageing - I didn't mean to be.

[msxyz]

No harm done :) It's always good to see people willing to explain.

[Red_Shift]

True HDR is no simulation, it's as straightforward as LDR, it's just a higher precision.
I highly doubt R520 will be able to apply AA with true HDR, we'll see that tomorrow.

[SH64]

True HDR is no simulation, it's as straightforward as LDR, it's just a higher precision.
I highly doubt R520 will be able to apply AA with true HDR, we'll see that tomorrow.

Yep tomorrow is the day .. expect some leakege tonight though! ;)

[Lfctony]

Tonight as in 2-3 hours maybe? :p I have to get up at 0500 tomorrow morning. :)

[rohit]

But dont the nv4x and g7x gpu's do HDR+AA in Luna demo?
From what i know, its HDR with 4x AA.

[Subtestube]

But dont the nv4x and g7x gpu's do HDR+AA in Luna demo?
From what i know, its HDR with 4x AA.

Yes it does, however that's done via a different method (I read a little, and I stress a little, about it a while back). I can't recall how they did it, but it was very very clever - this is what nVIDIA's pushing in any case - in an interview with some nV guy, the chap said something like (although not recalling where the interview was, I can't give you a linke or an exact quote) "well, HDR with AA in hardware is just a bad solution - we'd like to see people using a software solution [similar to what is used in Luna]".

EDIT: I should note that that's his opinion - I guess until we see performance figures for ATi's hardware implementation, we won't actually know for ourselves.