AMD Radeon RDNA2 Navi (RX 6800, 6800 XT, 6900 XT) [2020-10-28]

Discussion in 'Architecture and Products' started by BRiT, Oct 28, 2020.

  1. JoeJ

    Veteran Newcomer

    Joined:
    Apr 1, 2018
    Messages:
    1,053
    Likes Received:
    1,239
    Indeed! Should not take that long and might explain... :)
    I still lack DXR experience, but the concept of top / bottom level AS usually is:
    Build high quality tree per model. (Usually only once and offline, but DXR does it on client CPU on model load.)
    Build low quality top levels per frame over the set of active models. (DXR on GPU - even for thousands of sub trees this should give no perf problems.)
    DXR seems fine here? It only lacks the option to cache bottom AS to disk, which could be added.

    One thing is quite ironic to me:
    When many people said 'realtime RT is not possible because building AS takes too long', i laughed because i knew the top / bottom split idea had already solved this problem since centuries.
    Then when RTX came out, it took me quite some time to realize the problem is suddenly back for open world games.
     
  2. 3dcgi

    Veteran Subscriber

    Joined:
    Feb 7, 2002
    Messages:
    2,465
    Likes Received:
    350
    Navi21 can rasterize 4 primitives/clock as can XSX and PS5. Navi21 will be better at tessellation and some other circumstances though, such as reaching its peak pre-cull rate more often. How did you conclude XSX has a higher throughput that the 6800?
     
  3. pharma

    Veteran Regular

    Joined:
    Mar 29, 2004
    Messages:
    4,108
    Likes Received:
    3,230
    AMD to Produce Reference Design RX 6800 XT and RX 6800 Only Until "Early 2021"
    https://www.techpowerup.com/274887/...-rx-6800-xt-and-rx-6800-only-until-early-2021
     
    Lightman likes this.
  4. Leoneazzurro5

    Newcomer

    Joined:
    Aug 18, 2020
    Messages:
    217
    Likes Received:
    239
    The vanilla 6800 has one less SE so one less rasterizer. But higher clocks, and it not known if pre-cull numbers are the same.
     
  5. chris1515

    Legend Regular

    Joined:
    Jul 24, 2005
    Messages:
    5,968
    Likes Received:
    6,084
    Location:
    Barcelona Spain
    Congrats for the GPU and the console, I was afraid for the consoles after Vega 7 release but happy after RDNA release and extatic after RDNA 2 presentation.
     
    #1005 chris1515, Nov 19, 2020
    Last edited: Nov 19, 2020
    Lightman and 3dcgi like this.
  6. Digidi

    Regular Newcomer

    Joined:
    Sep 1, 2015
    Messages:
    381
    Likes Received:
    205
    Thank you for Testing CarstenS.
    Hmm Strange, here is a quote from a programmer answering my questions on twitter, maybe you have to activate the new pipilen, so the old byond3d suite test is now not working anymore? :



     
    #1006 Digidi, Nov 19, 2020
    Last edited: Nov 19, 2020
    Lightman, chris1515, Krteq and 2 others like this.
  7. 3dcgi

    Veteran Subscriber

    Joined:
    Feb 7, 2002
    Messages:
    2,465
    Likes Received:
    350
    I hadn't realized an entire SE was harvested for the 6800. That would reduce the triangle rasterization rate, but Navi21 has enough pre-cull launch capability per SE that it's limited by the Geometry Processor and not the number of SEs in this case.
     
  8. 3dcgi

    Veteran Subscriber

    Joined:
    Feb 7, 2002
    Messages:
    2,465
    Likes Received:
    350
    Digidi, don't look at Navi10. There are some inconsistencies in performance there that will only confuse things. The quoted rates for Navi21 are more robust and thus more easily measured.
     
  9. techuse

    Regular Newcomer

    Joined:
    Feb 19, 2013
    Messages:
    618
    Likes Received:
    358
    Which review has these synthetic benchmarks?
     
  10. Digidi

    Regular Newcomer

    Joined:
    Sep 1, 2015
    Messages:
    381
    Likes Received:
    205
    @CarstenS Can you maybe post the beyond3d polygon information from 3090 and 6800xt ? This will be very nice. When you reffer the values was this with culling or withouth culling? I can remember that you stated that N10 was better then the 2080ti without culling.

    ------------------------------------------------------------------------------------------------------------------

    What is confusing is that Navi21 has indeed 8 Scan/converter (Rasterizer) when you look into the linux and macos driver. That make it strange. Normaly it should rasterize 8 primitives/clock.
    Linux:
    https://www.pcgamer.com/a-linux-update-may-have-let-slip-amd-big-navis-mammoth-core/
    MaxOs:

    --------------------------------------------------------------------------------------------------------------

    This is also strange. Why do you make a backend of 128rops when the frontend can only deliver 1/2 of the pixel of the backend?
     
    #1010 Digidi, Nov 19, 2020
    Last edited: Nov 19, 2020
  11. pharma

    Veteran Regular

    Joined:
    Mar 29, 2004
    Messages:
    4,108
    Likes Received:
    3,230
    PSman1700 likes this.
  12. PSman1700

    Veteran Newcomer

    Joined:
    Mar 22, 2019
    Messages:
    4,264
    Likes Received:
    1,910
    Their still behind NV for the most, 6800XT is somewhere between 3070 and 3080 in normal rendering. In RT its very much behind its not even a discussion. DLSS is a whole different matter, as is BW/4k performance which is kinda why people get next gen products in this range i assume. With this were talking about a 6800xt thats north of 20TF's worth of raw power with IC/full rdna2, over double of what console got.
    That lands them in the mid range GPU segment and even less so for RT and DLSS, AI/tensor aside.

    Like someone else noted, its abit like zen2, AMD comes closer, but still not there. When 2013 consoles launched, they where more competitive on all fronts (GCN vs kepler/7950 vs 670 etc) then today. So yes, i'd had liked to see even more GPU in them for sure, tech is moving very fast still.
    Same for Zen2, feels they missed the boat somewhat there, Zen3 is a rather large IPC improvement. You cant have too much CPU this day and age with 120fps and more madness. 16GB will be OK considering SSD's, but same there, had they had more ram, the SSD's could have loaded even more to VRAM at once. I know where talking about consoles which means compromises, but since its being taken up id share my opinion (dream). The 2001 xbox was basically on par with the most powerfull GPU at launch, same for 360 and PS2. Today we dont get that anymore :p
     
    xpea and Rootax like this.
  13. Kaotik

    Kaotik Drunk Member
    Legend

    Joined:
    Apr 16, 2003
    Messages:
    9,595
    Likes Received:
    3,711
    Location:
    Finland
    Is NVIDIA still bringing more FE's? Since FE is the only 3070 ever sold at MSRP, AIB cards are way higher, and it's FE was so limited only few select NVIDIA storefronts had any to sell (not betting my head on this, but I think it was mentioned somewhere only two European NVIDIA stores had any)
    AMD has confirmed to produce references 'till sometime in Q1/21 and is expected to re-stock their own store too (which sells at MSRP guaranteed)
     
  14. pjbliverpool

    pjbliverpool B3D Scallywag
    Legend

    Joined:
    May 8, 2005
    Messages:
    8,446
    Likes Received:
    2,626
    Location:
    Guess...
    They use a good selection of the latest games in their benchmarks. Generally speaking it seems that games releasing on the new consoles perform relatively better on RDNA2 than "last gen" games, potentially to the point of the 6800XT being faster than the 3080 on average, at least at 1440p and very possibly at by future preferred resolution of 3440x1440p. I expect that trend to grow stronger over time as games come to take more advantage of RDNA2.

    That combined with the additional VRAM and cheaper price are almost enough to seal the deal for me to go with a 6800XT. However RT and DLSS are the two big wild cards.

    RT - I know many will say it doesn't matter that much but if the current trend holds then a very high proportion of games released on the next gen consoles (aka, pretty much all games) will feature some form of RT from now on. So in a way, looking at non RT performance today is like looking at performance without Antialiasing at the start of the last generation. i.e. largely irrelevant. And in that measure, if looks like Ampere may still have an advantage even when developers start to specifically target RDNA's RT hardware in the consoles. Then again, given the performance hit it may be that it gradually falls out of use on consoles with the current run just being a dash to include it as check box feature. That will limit it's applicability on the PC and nullify much of Nvidia's advantage here.

    DLSS - I have zero, I mean precisely zero confidence that AMD will release a MLSS solution that is comparable to DLSS in quality or performance any time soon. Probably not before I'm looking to get my next GPU. Meanwhile DLSS itself, while not widely used, is not really niche either, and does feature in quite a few big name titles including the must have CB 2077. And despite some claims to the contrary, I think that where it's available it's a no brainer to use and is at least comparable to native resolution. I'd previously expected Nvidia to release a game agnostic version of it which would have essentially been game over, but I'm doubting that to be the case now, so it's relevance to me hinges on it's take up.

    So in conclusion, I'm torn and don't know which to get!
     
    Cuthalu, xpea and PSman1700 like this.
  15. CarstenS

    Legend Veteran Subscriber

    Joined:
    May 31, 2002
    Messages:
    5,279
    Likes Received:
    2,945
    Location:
    Germany
    Much increased polygon rates notwithstanding: What do those have to do with the amount of rasterizers? They are tested separately.
     
  16. pjbliverpool

    pjbliverpool B3D Scallywag
    Legend

    Joined:
    May 8, 2005
    Messages:
    8,446
    Likes Received:
    2,626
    Location:
    Guess...
    I was assuming it only features 3 active Shader Engines and so 3 primitive units. I know there's no confirmation of that yet but I think we have had 96 ROPS confirmed which would suggest the entire 4th SE might be disabled. Happy to be told I'm wrong though!
     
  17. Digidi

    Regular Newcomer

    Joined:
    Sep 1, 2015
    Messages:
    381
    Likes Received:
    205
    I thought polygon rates means how many polygons can be transfert to pixel by the rasterizer (scan converter)? Am i wrong?
     
  18. Leoneazzurro5

    Newcomer

    Joined:
    Aug 18, 2020
    Messages:
    217
    Likes Received:
    239
    Well yeah, around 5-8% slower in 4K, on par at 1440p and dusting it below that compared to a 3080 in rasterization (depending on the test suite it could also be fastr) can be also called "somewhere in between" but I think you took the meaning quite too far. Also ignoring lower power, cheaper, and with more VRAM than both competitors. I dunno about 10 Gbytes, but 8 Gigabytes of VRAM will soon be a limit.
     
  19. Kaotik

    Kaotik Drunk Member
    Legend

    Joined:
    Apr 16, 2003
    Messages:
    9,595
    Likes Received:
    3,711
    Location:
    Finland
    Erinyes, Lightman and Silent_Buddha like this.
  20. 3dcgi

    Veteran Subscriber

    Joined:
    Feb 7, 2002
    Messages:
    2,465
    Likes Received:
    350
    I suspect there's some subtlety with those defines. The front end of the scan converter matters for triangle throughput, but in order to scale the pixel rate maybe the back end is implemented differently. ;)
     
Loading...

Share This Page

  • About Us

    Beyond3D has been around for over a decade and prides itself on being the best place on the web for in-depth, technically-driven discussion and analysis of 3D graphics hardware. If you love pixels and transistors, you've come to the right place!

    Beyond3D is proudly published by GPU Tools Ltd.
Loading...