SLI question

[GundamSonicZeroX]

I was told that the same part that does HDR does AA. And I hear different answers to "Can you do HDR with AA in SLI?" I mean, one card can do HDR and the other card can do AA right?

 

[Ulfhednar]

In a word: No.

Nvidia hardware, in no shape or form, can currently do HDR&AA.

You need ATI X1K for this currently.

 

[GundamSonicZeroX]

Dammit. Well, I can at least enable it in Source.

 

[Ulfhednar]

Aye, you can do it in source as it doesn't use proper FP32 HDR. Still looks very pretty though.

 

[GundamSonicZeroX]

Yeah, I know about the FP32 HDR. I can't believe that Dark Messiah looks like the best game ever without FP32 HDR.

 

[Ulfhednar]

Oblivion FTW.

 

[BFG10K]

If one card can't do it then two can't either.

 

[josh6079]

SLI can't but Quad-SLI can. (j/k)

 

[BFG10K]

Yeah, I know about the FP32 HDR.

There is no FP 32 HDR. Currently the highest is FP 16 RGBA for a total of 64 bits.

 

[tuteja1986]

Originally posted by: GundamSonicZeroX
Yeah, I know about the FP32 HDR. I can't believe that Dark Messiah looks like the best game ever without FP32 HDR.

Gundam :! ;( poor kid ... i feel for you dieing love for Gundam Watch Gundam Stargazer yet ?

HDR with AA in Oblivion :! HDR with AA ion Dark Messiah is very good :! depends on your monitor and its bloody brightness leak

 

[GundamSonicZeroX]

Originally posted by: BFG10K

Yeah, I know about the FP32 HDR.

There is no FP 32 HDR. Currently the highest is FP 16 RGBA for a total of 64 bits.

Hmm, I must have been misinformed.

 

[TanisHalfElven]

Originally posted by: GundamSonicZeroX

Originally posted by: BFG10K

Yeah, I know about the FP32 HDR.

There is no FP 32 HDR. Currently the highest is FP 16 RGBA for a total of 64 bits.

Hmm, I must have been misinformed.

hey i can't belive i'm quoated in a sig. COOOOOOOOOOOOOOOOOOOOL.

 

[Sonikku]

You can still get a poor man's HDR +AA in Half Life 2 at least.

 

[avi85]

this is an interesting concept, why can't this be implemented in a hacked driver?
if it is a technical problem of the same core not being able to do AA & HDR at the same time then in SLI one could do the AA and the other one should be able to do HDR

 

[Dethfrumbelo]

Originally posted by: avi85
this is an interesting concept, why can't this be implemented in a hacked driver?
if it is a technical problem of the same core not being able to do AA & HDR at the same time then in SLI one could do the AA and the other one should be able to do HDR

My limited understanding is that the same bits that do the AA are also the ones tasked to do HDR in Nvidia cards, so it can only do one or the other. It's a hardware limitation and there's no getting around it.

 

[Munky]

The technical explanation is that the hardware which does multisampling AA can not perform MSAA on floating point buffers. So, there's no way to get one card to do HDR and one to do MSAA as long as you want to keep using floating point buffers for HDR rendering.

The only possibility I can think of is if the card does HDR, only renders the image at 4x the required resolution. Then a shader program scales down the HDR data while performing a filter that averages the values of several pixels into 1 resulting pixel. That's what happens in AOE3, and in effect you get supersampled AA with HDR. But that functionality was coded in the game engine, I'm not sure if the driver itself could do it. Also, it would not require SLI, since one card could do it, although the performance would not be the same as on the x1k cards.