Question Speculation: RDNA2 + CDNA Architectures thread

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uzzi38

uzzi38

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Oct 16, 2019
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All die sizes are within 5mm^2. The poster here has been right on some things in the past afaik, and to his credit was the first to saying 505mm^2 for Navi21, which other people have backed up. Even still though, take the following with a pich of salt.

Navi21 - 505mm^2

Navi22 - 340mm^2

Navi23 - 240mm^2

Source is the following post: https://www.ptt.cc/bbs/PC_Shopping/M.1588075782.A.C1E.html
 
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TESKATLIPOKA

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May 1, 2020
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As mentioned at beyond3d by Jawed, N23(236mm2) is 50% bigger than Navi14(157mm2). It doesn't make sense, that It should be only 32CU GPU with 128bit GDDR6 when Navi 14 has 24CU and 128bit GDDR6. The difference in the supposed specs is only 8CU and 1 RDNA1 CU is ~2.1mm2, so the difference should be ~17mm2 instead of 79mm2, yet It's not.
 
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Saylick

Saylick

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Sep 10, 2012
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TESKATLIPOKA said:
As mentioned at beyond3d by Jawed, N23(236mm2) is 50% bigger than Navi14(157mm2). It doesn't make sense, that It should be only 32CU GPU with 128bit GDDR6 when Navi 14 has 24CU and 128bit GDDR6. The difference in the supposed specs is only 8CU and 1 RDNA1 CU is ~2.1mm2, so the difference should be ~17mm2 instead of 79mm2, yet It's not.
Click to expand...
Infinity Cache?
 
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K

Karnak

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Jan 5, 2017
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Yuko is wrong according to ExecutableFix (was the one leaking Cezanne/Lucienne earlier). Besides that doesn't make any sense to me either what Yuko is saying.
 
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lixlax

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Nov 6, 2014
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So the leaks are suggesting N21= 80CU; N22=40CU; N23=32CU and N24=24CU? Doesn't make sense to me- Navi 22-24 all close together and then huge cap to Navi 21.

Also the leaked clockspeeds are all over the place- anywhere from 2GHz-2.5GHZ.
 
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Bigos

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Jun 2, 2019
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stebler said:
Navi 22 10 GiB version
https://twitter.com/x/status/1318117797562646528
Click to expand...

There haven't been many GPUs missing a 32-bit part of the memory bus [1]. This means that it has either a misbalanced memory configuration (some memory channels having more memory than others) or a cut-down 160-bit memory bus.

However, if we assume that Navi 22 has 384-bit memory bus then the answer is straight-forward - the cut down version has one double-memory controller less, 320-bit in total. This would also mean that every other rumored bus size, like N21 being 256-bit, should also be multiplied by 2. In my opinion that is a more likely explanation than the "infinity cache" that would magically cut the memory bandwidth needs of a huge GPU in half (the cache might still exist but have a different purpose, e.g. to speed up unpredictable memory access patterns of ray tracing BVH traversal).

Please note though that this is just my assumption that might be completely wrong.

[1] Technically, single GDDR6 channel is 32-bit. Looking at the wiki page, it seems there was at the very least a cut-down GeForce 1050 with 96-bit bus, and 1080Ti/2080Ti use 352-bit bus. For AMD, there is a single cut-down Navi-14. Not many in total.

List of Nvidia graphics processing units - Wikipedia

en.wikipedia.org en.wikipedia.org

List of AMD graphics processing units - Wikipedia

en.wikipedia.org en.wikipedia.org
 
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Glo.

Glo.

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Apr 25, 2015
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Bigos said:
There haven't been many GPUs missing a 32-bit part of the memory bus [1]. This means that it has either a misbalanced memory configuration (some memory channels having more memory than others) or a cut-down 160-bit memory bus.

However, if we assume that Navi 22 has 384-bit memory bus then the answer is straight-forward - the cut down version has one double-memory controller less, 320-bit in total. This would also mean that every other rumored bus size, like N21 being 256-bit, should also be multiplied by 2. In my opinion that is a more likely explanation than the "infinity cache" that would magically cut the memory bandwidth needs of a huge GPU in half (the cache might still exist but have a different purpose, e.g. to speed up unpredictable memory access patterns of ray tracing BVH traversal).

Please note though that this is just my assumption that might be completely wrong.

[1] Technically, single GDDR6 channel is 32-bit. Looking at the wiki page, it seems there was at the very least a cut-down GeForce 1050 with 96-bit bus, and 1080Ti/2080Ti use 352-bit bus. For AMD, there is a single cut-down Navi-14. Not many in total.

List of Nvidia graphics processing units - Wikipedia

en.wikipedia.org en.wikipedia.org

List of AMD graphics processing units - Wikipedia

en.wikipedia.org en.wikipedia.org
Click to expand...
We know the specs for Navi GPUs.

N21 has 256 bit GDDR6, N22 has 192 bit GDDR6, N23 has 128 bit GDDR6 memory controller.

You can easily get 160 bit bus from N22 cut down version.
 
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K

Konan

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Jul 28, 2017
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lixlax said:
So the leaks are suggesting N21= 80CU; N22=40CU; N23=32CU and N24=24CU? Doesn't make sense to me- Navi 22-24 all close together and then huge cap to Navi 21.

Also the leaked clockspeeds are all over the place- anywhere from 2GHz-2.5GHZ.
Click to expand...

It could come out something similar to fill the gaps -

Navi 21a = XT = 80CU = boost clock 2050Mhz
Navi 21b = XTL = 72 CU = boost clock 2200Mhz
Navi 21 = XL = 64CU

There should be 2 to 3 SKUs cut from Navi 21.
It was speculated before regarding there was an XTX variant the "secret one" that only AMD has - and that could still come out but "KittyCorgi" (Yuko) above is not saying so today.
 
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Glo.

Glo.

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Apr 25, 2015
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Konan said:
It could come out something similar to fill the gaps -

Navi 21a = XT = 80CU = boost clock 2050Mhz
Navi 21b = XTL = 72 CU = boost clock 2200Mhz
Navi 21 = XL = 64CU

There should be 2 to 3 SKUs cut from Navi 21.
It was speculated before regarding there was an XTX variant the "secret one" that only AMD has - and that could still come out but "KittyCorgi" (Yuko) above is not saying so today.
Click to expand...
Navi 22 has XTL.

There is no XTL for Navi 21 GPUs.

Speaking about KittyCorgi, I think at this point in time its pretty clear that his sources have access not to the Big Navi but to Navi 22 GPUs, and if we bare this in mind, everything what he posted makes sense, now.
 
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K

Konan

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Glo. said:
Navi 22 has XTL.

There is no XTL for Navi 21 GPUs.

Speaking about KittyCorgi, I think at this point in time its pretty clear that his sources have access not to the Big Navi but to Navi 22 GPUs, and if we bare this in mind, everything what he posted makes sense, now.
Click to expand...
Yep that could be very true too.
 
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lightmanek

lightmanek

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Feb 19, 2017
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blckgrffn said:
Resurrect the ability to turn an XL into an XT!

...thinks fondly of the x1800 XL he bought back in the day that was tricked into being an XT...

XT PE is even better. More letters!
Click to expand...
Or My 9500 Non-Pro into 9700 Pro, these were the times! (Yes, it would be nice if something akin to a mythical R300 came out of ATi's labs ... (errr or is it AMD now?)
 
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Glo.

Glo.

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parkerface said:
Digital Foundry just uploaded a video highlighting Xbox Series X power and thermals.

Few quick takeaways are Rise of the Tomb Raider peaked at 151W, Dead or Alive 6 at 165W, and Gears 5 at 211W. Richard even made a nod to Big Navi at the end of the video, which I thought was amusing.
Click to expand...
Why is Digital Foundry Hyping up RDNA2 architecture?

Its going to be crap, after all.
 
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