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Question Speculation: RDNA2 + CDNA Architectures thread

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raghu78

Diamond Member
Aug 23, 2012
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Yes, guys. Kepler_L2 is correct.

Historically XT and XTX are full dies. They just differ by clock speeds, and power targets.

So its not 72 CUs. Its full, 80 CUs, with 2.4 GHz game clock, at 255W of power drawn(hence the TGP).

Im lost. Its GG. Its beyond EVERYTHING we thought it could possibly be.

80CU vs 82SM 72CU vs 68SM 72CU vs 68SM

What we will see.

So if kopite is right and I tie the info VCZ said about XTX having more CU than XT then its obvious that

RX 6900 XT = Navi 21 XTX = 80/16GB /128 ROPs (fully enabled)
RX 6900 = Navi 21 XT = 72,/16GB/128 ROPs (4 WGP disabled)
RX 6800XT = Navi 21 XL = 72/16GB/112 ROPs (1 SA fully disabled)
RX 6800 = Navi 21 XE = 60/12GB/96 ROPs (1 SE disabled with 64 bit G6 MC disabled)

Navi21 XT > Base clock 2000MHz to 2100MHz > Boost clock around 2400MHz

https://twitter.com/T4CFantasy/status/1316618720148676608
2160 / 2410
 
Last edited:

andermans

Junior Member
Sep 11, 2020
14
17
36
Wouldn't the game clock be pretty much equal the boost clock if you give it enough cooling & power? I've looked at the clock speed graphs of some Rx 5700 XT AIB reviews on TPU and most stay pretty damn near the advertised boost speed.
 

Glo.

Diamond Member
Apr 25, 2015
4,471
2,924
136

80CU vs 82SM 72CU vs 68SM 72CU vs 68SM

What we will see.

So if kopite is right and I tie the info VCZ said about XTX having more CU than XT then its obvious that

RX 6900 XT = Navi 21 XTX = 80/16GB /128 ROPs (fully enabled)
RX 6900 = Navi 21 XT = 72,/16GB/128 ROPs (4 WGP disabled)
RX 6800XT = Navi 21 XL = 72/16GB/112 ROPs (1 SA fully disabled)
RX 6800 = Navi 21 XE = 60/12GB/96 ROPs (1 SE disabled with 64 bit G6 MC disabled)

Navi21 XT > Base clock 2000MHz to 2100MHz > Boost clock around 2400MHz

https://twitter.com/T4CFantasy/status/1316618720148676608
2160 / 2410
Or...

80 CU/High clocks - XTX, 80CU/Low clocks - XT, 72/high clock - XL, 72/low clock - XE.

And Navi 24 is actually 64 CU die.

Because that way it also makes absolute sense.
 
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raghu78

Diamond Member
Aug 23, 2012
4,091
1,460
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Or...

80 CU/High clocks - XTX, 80CU/Low clocks - XT, 72/high clock - XL, 72/low clock - XE.

And Navi 24 is actually 64 CU die.

Because that way it also makes absolute sense.
N24 is not 64 CU. N24 is a small die with 16-20 CU and < 150 sq mm. You have to remember N23 according to Acquariuszi is 240 sq mm.
 

Timorous

Senior member
Oct 27, 2008
481
369
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80 CUs @ 2.4Ghz game clocks.

With 80% CU scaling, 50% clock scaling and 0% IPC increase vs 5700xt you get, 1.8 × 1.125 = 2.025x 5700XT. This is 3080 performance.

This is conservative.

72CUs with 80% CU scaling, 50% clock scaling and 10% IPC gets 1.64 × 1.125 × 1.1 = 2.0295x 5700XT.

Even with conservative CU scaling and clock scaling numbers a 72 CU card with a 10% IPC gain will be trading blows with the 3080.

If clock scaling and or CU scaling is better than these numbers the top 80CU card should easily beat the 3090.
 

Glo.

Diamond Member
Apr 25, 2015
4,471
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Thats a really high clock but what important is performance. If its on par with 3080 I'd call that a victory for AMD.
Which SKU in particular you are talking about, being on par with RTX 3080?

Because maybe you missed, but there is no way in hell top SKU is only on par with 3080. No way, in hell.
 
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Timorous

Senior member
Oct 27, 2008
481
369
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Which SKU in particular you are talking about, being on par with RTX 3080?

Because maybe you missed, but there is no way in hell top SKU is only on par with 3080. No way, in hell.
Agreed. If these clocks hold in games then it is looking 3090ish minimum.
 

Vope45

Member
Oct 4, 2020
48
58
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Which SKU in particular you are talking about, being on par with RTX 3080?

Because maybe you missed, but there is no way in hell top SKU is only on par with 3080. No way, in hell.
The Xt variants, XTX at this point will most likely be a higher clock version of the XT, I really hope not though.
 

linkgoron

Golden Member
Mar 9, 2005
1,969
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If what I've seen is correct, AMD have been using the XT moniker on GPU code-names for years to signify the fully enabled chip (found one example in the last ten years where it wasn't). Why would they change it now? XTX has been used a few times recently (Navi 10, 14, and less recently in 2013...) to signify a more highly-clocked fully-enabled chip. They might change it, but IMO it's unlikely.

What we've seen from AMD has been a card slower by around 10% than the 3080, and people here are talking about beating the 3090 by 10-15%. I'll be happy if AMD can produce a 5% winner vs the 3080. People here are leading themselves to disappointment. People should go re-read the Vega thread. The same user, using the same tactics, overhyping yet another AMD launch.



Which SKU in particular you are talking about, being on par with RTX 3080?

Because maybe you missed, but there is no way in hell top SKU is only on par with 3080. No way, in hell.
I will leave you with this spoiler to the Vega thread:
1602981002814.png
 

Glo.

Diamond Member
Apr 25, 2015
4,471
2,924
136
If what I've seen is correct, AMD have been using the XT moniker on GPU code-names for years to signify the fully enabled chip (found one example in the last ten years where it wasn't). Why would they change it now? XTX has been used a few times recently (Navi 10, 14, and less recently in 2013...) to signify a more highly-clocked fully-enabled chip. They might change it, but IMO it's unlikely.

What we've seen from AMD has been a card slower by around 10% than the 3080, and people here are talking about beating the 3090 by 10-15%. I'll be happy if AMD can produce a 5% winner vs the 3080. People here are leading themselves to disappointment. People should go re-read the Vega thread. The same user, using the same tactics, overhyping yet another AMD launch.





I will leave you with this spoiler to the Vega thread:
The GPU that they have showed might have not been neither XTX, nor XT, but XL, per this:
and this:
So basically, low clocked version of 72 CU die, with this level of clocks: https://twitter.com/_rogame/status/1317584994156617729

I perfectly understand where you guys coming from with disbelief about Navi 2.

But NOTHING so far points to reality, that this time AMD underperformed in any way shape or form. This is the real deal.

P.S. Shoot the message, not the messenger. Your post will age really badly.
 
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linkgoron

Golden Member
Mar 9, 2005
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The GPU that they have showed might have not been neither XTX, nor XT, but XL, per this:
and this:
So basically, low clocked version of 72 CU die. https://twitter.com/_rogame/status/1317584994156617729

I perfectly understand where you guys coming from with disbelief about Navi 2.

But NOTHING so far points to reality, that this time AMD underperformed in any way shape or form. This is the real deal.
1602982113483.png

1602982299093.png
 

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