What rendering tricks might RSX employ?

Discussion in 'Console Technology' started by Shifty Geezer, Jun 13, 2005.

  1. Titanio

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    I think it may become a choice of 1080p with 2xAA or none vs 720p with 4xAA. The bandwidth requirements, at a guess, are probably similar between the two?

    If bandwidth was really really tight with your game without HDR, and you wanted to do it, David Kirk mentioned it as something that you could ship off to Cell, where you could allow it to eat Cell's internal bandwidth all it wanted. Sure, RSX has a nice implementation for HDR there (or at least a high precision one), but if bandwidth is more precious to you than that, it might become an option for you.

    I'm not really sure how big a problem bandwidth will be though. Again, how much bandwidth does a 2xAA or a 4xAA 720p frame take? (I'm not suggesting it's not a lot, btw, I know it is - I literally would just like to know so we can get a rough idea of where things stand).
     
  2. marconelly!

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    Can't you use FSAA on graphics before it's merged with HDR buffer, or something like that? I thought that was possible.
     
  3. mckmas8808

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    Lets just be honest Thegameman the Xbox blew away the PS2 and GC in the graphics department. It wasn't even close. Yes some games on both system did what they were meant to do but most couldn't compare.

    I don't think we will see any titles using a fp32 hdr anytime soon. I believe that it will cause a massive bandwidth hit .



    So what was the Alfred/Doc Ock demo used for? So is everything that they were explaining a waste of time? I understand marketing but wouldn't that only make Sony look worst if everything they demoed (i.e. Doc Ock, Getaway, etc) couldn't be possible at all.


    And is what Squeak posted correct? I don't see why it couldn't be. Wasn't that in a way the point of half the tech demos?
     
  4. pc999

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    From what I read, I got the impression that xenus would be very bad performer in older games and other rez than 720p comparatively to desktop cards, I may be wrong, but that would be a big disvantage (not in a closed box) to the desktop part.

    BTW I thought that RSX only has 35G of BW total(Vram+XDR) :? .
     
  5. jvd

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    I belive you can , but i believe the nv40 lacks this feature . There is no game or benchmark out that allows fsaa and hdr to be used at the same time . At least htat i've heard about

    edit : I should mention i don't know how the work around works . but ibelieve it works in the xenos . I'm unsure of the r520 or future nvidia products though as there has been no talk about it
     
  6. Titanio

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    128-bit HDR was not mentioned in relation to either the Doc Oc demo or The Getaway demo. That's not what those demos are about. The Getaway was apparently being done wholly on Cell, so I'm not sure if it could be using 128-bit HDR or not.

    Combined VRam and XDR bandwidth is 47GB/s. RSX has 57GB/s of external bandwidth which is a subtly different figure (35GB/s of that could be going to Cell - the SPEs' local memory and L2 cache - and to XDR, but XDR bandwidth tops out at 25GB/s).
     
  7. Thegameman

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    I don't think that xbox games are blowing away anything on gamecube on PS2 the diference is a little more,NG,DOA,RSC2 are some of the most graphical games on xbox,GT4 and GOW look very on par with this games,the xbox games have and edge cleaner picture less jagies and a little chraper graphics,but nothing out of this world,RS3 and RE4 look on par with xbox games as well,what you don't see is that GT4 hold incredible well to xbox games,the problem is that most xbox games look great and almost all PS2 games look bad,but few that take advantage of the PS2,do stand out and can be even compare side by side like GT4 and Forza,which should not be the case cuz the xbox is 20 months newer than the PS2.

    If you compare the xbox most graphical games to the Gamecube or PS2 average games it does,but well made games on both the gamecube and the PS2 look to be on par.

    My 2 cents
     
  8. SteamedRice

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    what HDR mode was on the unreal 2k7 at 720p in sony conference that tim sweeny showed with 2 months work and working with cell only? That looked impressive with no slowdowns and Getaway demo too with just cell alone.

    Dunno but maybe cell+rsx is powerful enough to do hdr smoothly instead of thinking bandwidth this and that like these are PC video cards running on athlon 64s on winXP compared to fully gaming console.
     
  9. Titanio

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    UE3 was using the GPU. Its CPU utilisation was limited to the PPE, perhaps that's what you're confusing it with.
     
  10. wco81

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    I could have sworn Phil Harrison pointed out HDR in the context of panning over the buildings in the London demo.
     
  11. pc999

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    Thanks.
     
  12. Titanio

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    128-bit HDR? Anyway, the point of the demo still wasn't HDR. And it was apparently running only on Cell anyway, so it doesn't tell us much about HDR in RSX ;)
     
  13. wco81

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    I thought he said something like "you could see the effects of the HDR here in the details."

    But I don't recall him saying that demo was only using the Cell, although I know they said that later.

    Plus most of it was outdoor scenes in direct sunlight. I don't recall if they panned over some areas which were in shade.

    It wouldn't make sense to highlight HDR on some facade of a building directly and brightly lit.
     
  14. Titanio

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    I can't remember what was in the vid, but some of the shots are in the shade:

    http://ps3media.ign.com/ps3/image/article/616/616976/the-getaway-ps3-20050519100625263.jpg

    http://ps3media.ign.com/ps3/image/article/616/616976/the-getaway-ps3-20050519100624154.jpg

    http://ps3media.ign.com/ps3/image/article/616/616976/the-getaway-ps3-20050519100623263.jpg
     
  15. talyn99

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    Yeah well, kind of a contradiction. If the best games on PS2 and Cube are on par with the best X-box games. Then the X-box must be even more grossly untapped than even the PS2. And if you believe the Kakizo(think that right) guys bloq-like page. Then the cell alone is akin to a few PS2 crammed on a chip. Come on people, if Sony was truly NOT blowing smoke up our collective asses in saying that the Getaway demo was running wholly on cell. Then to me this whole eDRAM thing is a moot point.

    On the PS2, developers could use the 2MB on the PS1 shrunken down chipset on the motherboard. Now, if the same holds true, and you have shrunken down chipset , WITH eDRAM, in theory, developers can use that as a back frame buffer cant they.

    Not to beat the Geo-texturing dead horse, not to mention what Shiney is doing. Normal-mapping, 1500 enemies on-screen at once, HMMMMMMM. Think people, clearly alot of you do not know as much as you pretend too.

    For the Cube and X-box versions, can the same be said, can they fit all those enemies onscreen at once. XDR RAM is way faster than the other RAM. I believe SOny will make that minor adjustment , since Samsung made that better albeit smaller XDR on a smaller die. If that is the case, cant the other Ram be used as a backframe buffer. Cause the eDRAM thing really gettin on my nerve. Cause every X-block fanboy hinging every damn thing on it.

    Lastly................... it;s said many developers moved x360 projects to PS3. My guess they know more than us.
    My two cents
     
  16. repi

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    No current graphics card can do MSAA on HDR surfaces. There are no tricks the get it either. You can do manual SSAA tough, but that's waay expensive.

    Xenos can do MSAA and it would be strange if RSX couldn't. Hope the next-gen PC cards also can do it because more and more games will use HDR rendering and gamers just have gotten used to 2x-4x MSAA and will probably not be that happy to see the return of the jaggies (tm).
     
  17. jvd

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    Right the xenos can . I don't know about the rsx . The rsx is looking like a version of the g70 which is based on the nv40. I don't know if the limitation in the nv40 will carry over so I don't want to comment .


    According to the xenos article the chip should not take a hit doing 4x fsaa and it should perform the same with fp10 hdr as it would with int format . So it should be extremely fast with that . I think we will see it used all the time as for the rsx I believe personaly that they will improve the efficency of fp16. But i think fp32 will be like what the fp16 performance is like on the 6800s . Basicly 40% + reduction in performance. However I think fp16 will be useable in almost all games with minimal performance hits
     
  18. talyn99

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  19. Shifty Geezer

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    The brightness of these scenes was dynamically rescaled during the footage to simluate exposure of a video camera. Harrison (if that's the right guy) mentions HDR lighting towards the clips end.
     
  20. Titanio

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    Yeah, to clarify they were emulating a number of optical effects to capture to look of a camcorder. That includes auto white balancing, auto focussing and DOF, so bear that in mind if you're scrutinising the shots ;)
     
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