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Question Speculation: RDNA2 + CDNA Architectures thread

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biostud

Lifer
Feb 27, 2003
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Update on AMD CPU support: SAM will likely be limited to Zen 3 since prior gens were only emulating the PDEP and PEXT instructions (native support made them 250 times faster according to Ian) that may be needed to access all of Resizable BAR. Intel supports them going back to Haswell (there BIOS support is the limiting factor for SAM support).

See eg:
https://www.reddit.com/r/Amd/comments/k6cbk7
So what you say is that intel is rolling it out on the X99 platform as well? ;)
 

Glo.

Diamond Member
Apr 25, 2015
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Basic maths suggests that if those clocks are correct, for desktop GPU, then Navi 23 SKU, with 128 bit bus, and 32 CUs should be around RTX 2070 Super performance with 120W total board power.

:)
No, I have to correct this.

32 CUs/128 bit bus with 2350 MHz.

RX 5600 XT Sapphire Pulse has 1750 MHz. N23 reference design appears to have 35% higher max boost clocks.

That alone should tell us that this die is going to be faster than RX 5600 XT, however, not as fast as RTX 2070 Super.


If RX 6700 XT is 10% above RTX 2080 Super, then cut down version will be roughly around standard 2080, then 36/160 bit version should be around 2070 Super, depending on the clock speeds.

So that leaves us with realistic potential of this GPU. RX 5700 XT/RTX 2070 performance levels.

If this is 1:1 Navi 14 replacement, and it will land in 6500 Series, AMD has just changed the game in entry/mainstream market.
 
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Mopetar

Diamond Member
Jan 31, 2011
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Will we get entry level pricing though? Even if supply constraints vanish by the time of release AMD have shown that they're willing to charge more when they offer better performance.

If the 6700XT is above the 3060 Ti by that much expect it to be priced above it as well and leave less of a gap between it and the 6800 than you would see with a $400 card. That drags up the price of everything else in the stack. It could be well into next year before either company has enough supply to act more aggressively with respect towards pricing. Ray tracing is also worth considerably less in the midrange so I don't see AMD undercutting Nvidia to compensate for any perceived weakness in the capabilities of their cards in this aspect either.
 

TESKATLIPOKA

Senior member
May 1, 2020
295
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The leak about 2350MHz in MorePowerTool Igor's Edition for N23 is not max turbo clock.
I asked another user from pctuning.cz named HEAD and he posted a screen for his RX 6800XT.


As you can see, RX 6800XT has 2577MHz, yet we know official turbo is only 2250MHz and that's 87.3% of GFX Maximum(2250/2577=0.873).
If the same applies to N23, then max turbo is ~2052MHz and not 2350MHz for this mobile part!
 

Saylick

Senior member
Sep 10, 2012
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I was browsing around and saw that Techspot put up a cool summary of Ampere vs RDNA 2: https://www.techspot.com/article/2151-nvidia-ampere-vs-amd-rdna2/

Don't think I've seen this image get posted anywhere so far though. Not sure if they got it from AMD footnotes or if it was a part of an AMD slide deck...

It really does look like for 1080p, 64 MB is where you start getting diminishing returns, while for 4K it looks like AMD could literally double it and the hit rate would go up proportionally (i.e. square root of 2 increase, ~1.41x). Regardless, the max feasible hit rate (the asymptote) looks to be around 80%.

 
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Glo.

Diamond Member
Apr 25, 2015
4,649
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The leak about 2350MHz in MorePowerTool Igor's Edition for N23 is not max turbo clock.
I asked another user from pctuning.cz named HEAD and he posted a screen for his RX 6800XT.


As you can see, RX 6800XT has 2577MHz, yet we know official turbo is only 2250MHz and that's 87.3% of GFX Maximum(2250/2577=0.873).
If the same applies to N23, then max turbo is ~2052MHz and not 2350MHz for this mobile part!
Does he have reference 6800 XT or AIB?
 

TESKATLIPOKA

Senior member
May 1, 2020
295
315
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I was browsing around and saw that Techspot put up a cool summary of Ampere vs RDNA 2: https://www.techspot.com/article/2151-nvidia-ampere-vs-amd-rdna2/

Don't think I've seen this image get posted anywhere so far though. Not sure if they got it from AMD footnotes or if it was a part of an AMD slide deck...

It really does look like for 1080p, 64 MB is where you start getting diminishing returns, while for 4K it looks like AMD could literally double it and the hit rate would go up proportionally (i.e. square root of 2 increase, ~1.41x). Regardless, the max feasible hit rate (the asymptote) looks to be around 80%.

This image is not new, It was mentioned and discussed in this thread before. You can check It at page 187-188.
This image could be seen even in reviews, at least at Techpowerup I saw It.
 
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Saylick

Senior member
Sep 10, 2012
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This image is not new, It was mentioned and discussed in this thread before. You can check It at page 187-188.
This image could be seen even in reviews, at least at Techpowerup I saw It.
Ah, I see. The slide wasn't explicitly posted in this thread but instead mentioned and then you gave a link to another forum which had it posted, hence why I missed it.
 

TESKATLIPOKA

Senior member
May 1, 2020
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Actually I had one post with It, but now after checking It, the image was missing(original linked source was deleted?), only text remained, so no wonder you didn't see It here.
I reuploaded back the image to my old post, so now It's how It used to be -> Link.
 
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Mopetar

Diamond Member
Jan 31, 2011
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I was browsing around and saw that Techspot put up a cool summary of Ampere vs RDNA 2: https://www.techspot.com/article/2151-nvidia-ampere-vs-amd-rdna2/

Don't think I've seen this image get posted anywhere so far though. Not sure if they got it from AMD footnotes or if it was a part of an AMD slide deck...

It really does look like for 1080p, 64 MB is where you start getting diminishing returns, while for 4K it looks like AMD could literally double it and the hit rate would go up proportionally (i.e. square root of 2 increase, ~1.41x). Regardless, the max feasible hit rate (the asymptote) looks to be around 80%.

If the graph is accurate, Navi 22 with 96 MB of infinity cache should be a monster for 1080p (and potentially 1440p) since the hit rate has already started to fall off by that point, especially for 1080p. We already know that cards like the 3080 and the 6800XT have more resources than they realistically need for that resolution and can't utilize all of them, so even though Navi 22 is half the number of shaders as Navi 21, it likely doesn't need them at 1080p. If it can get a much higher average boost we may see a much smaller performance gap than might normally be anticipated.
 
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pandemonium

Golden Member
Mar 17, 2011
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Nevermind! Crisis averted. There's a convert tool built into Windows to update the OS drive from MBR to GPT.


All of this talk of SAM has me legitimately confused.

Who actually isn't using CSM for UEFI mode to be able to take advantage of SAM right now?

Because if you are using Compatibility Support Module for UEFI, that means wiping your OS drive if it's Windows and starting over again. Also never being able to change the hardware attached to that drive without having to reinstall Windows again because in CSM mode, Windows can freak out; I've experienced it on a few occasions. Sometimes you'll get lucky and it won't. Either way it's a risk.

I'm pretty sure that 95% of the people that would want to take advantage of SAM, regardless of brand affiliation or hardware employed, have zero idea they probably can't or won't go through the lengths of getting it working.

Sure, it's great as far as a feature, but let's not fool ourselves here with how limited in actual implementation it will be in the real world.

Edit: Clarified.
 
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coercitiv

Diamond Member
Jan 24, 2014
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Looks like Tom's has a performance preview for CP2077 and it looks to be a pretty demanding, or unoptimized, game.
Possible plot twist, expect performance to change on release version, as the one Tom's benchmarked has some nasty DRM to prevent pre-release leaks from the press.

GamersNexus said:
FYI: Cyberpunk currently has DRM that is only active for reviewers and is known to reduce performance. Will not be active on launch day, therefore any testing published today will not accurately reflect launch performance. CDPR warned us of this, so we are waiting for launch day. Saying this because there is an article out there that is showing performance numbers, but CDPR directly told us that the early DRM is bad for performance and is *not present* in the consumer copy, therefore testing pre-launch is invalid and not representative of the game.

The early DRM is nothing evil, just to prevent leaks from reviewers or streamers to the public. As stated, it's not in the consumer copy, so we really have no problem with it. But it does mean testing should wait until the actual version of the game that people will play is out.
 

Leeea

Senior member
Apr 3, 2020
327
321
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All of this talk of SAM has me legitimately confused.

Who actually isn't using UEFI mode to be able to take advantage of SAM right now?

Because if you are using UEFI, that means wiping your OS drive if it's Windows and starting over again. Also never being able to change the hardware attached to that drive without having to reinstall Windows again because in CSM mode, Windows can freak out; I've experienced it on a few occasions. Sometimes you'll get lucky and it won't. Either way it's a risk.

I'm pretty sure that 95% of the people that would want to take advantage of SAM, regardless of brand affiliation or hardware employed, have zero idea they probably can't or won't go through the lengths of getting it working.

Sure, it's great as far as a feature, but let's not fool ourselves here with how limited in actual implementation it will be in the real world.
Legacy boot forever!

( I have been zapped with that, it is so annoying. )
 

moinmoin

Platinum Member
Jun 1, 2017
2,222
2,639
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All of this talk of SAM has me legitimately confused.

Who actually isn't using UEFI mode to be able to take advantage of SAM right now?

Because if you are using UEFI, that means wiping your OS drive if it's Windows and starting over again. Also never being able to change the hardware attached to that drive without having to reinstall Windows again because in CSM mode, Windows can freak out; I've experienced it on a few occasions. Sometimes you'll get lucky and it won't. Either way it's a risk.

I'm pretty sure that 95% of the people that would want to take advantage of SAM, regardless of brand affiliation or hardware employed, have zero idea they probably can't or won't go through the lengths of getting it working.

Sure, it's great as far as a feature, but let's not fool ourselves here with how limited in actual implementation it will be in the real world.
Now I'm confused. You mean to say most people still use legacy boot? Is that used by OEMs for pre-installed Windows? I always assumed legacy boot is a legacy option that can safely be ignored and shouldn't be in widespread use anymore 10 years after its introduction. Of course UEFI features won't be available using that, everybody knows that. Right? Right???
 

zinfamous

No Lifer
Jul 12, 2006
104,252
18,851
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What else do you expect from Toms 'Just Buy It' Hardware.
what do you mean? The Tom's article already explains:

--Denovu hurts CPU performance, so take with grain of salt
--CDPR told us that this review version is already unoptimized compared to the release version, and on top of that, there is a further day 1 patch. So, they at least explain that these benchmarks should be taken with a grain of salt.

Also consider that I don't imagine these were run with updated drivers.
 
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Timorous

Senior member
Oct 27, 2008
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what do you mean? The Tom's article already explains:

--Denovu hurts CPU performance, so take with grain of salt
--CDPR told us that this review version is already unoptimized compared to the release version, and on top of that, there is a further day 1 patch. So, they at least explain that these benchmarks should be taken with a grain of salt.

Also consider that I don't imagine these were run with updated drivers.
Seems like a pointless article with no real world applicability that was put out to garner clicks.
 

coercitiv

Diamond Member
Jan 24, 2014
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Stuka87

Diamond Member
Dec 10, 2010
5,294
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All of this talk of SAM has me legitimately confused.

Who actually isn't using UEFI mode to be able to take advantage of SAM right now?

Because if you are using UEFI, that means wiping your OS drive if it's Windows and starting over again. Also never being able to change the hardware attached to that drive without having to reinstall Windows again because in CSM mode, Windows can freak out; I've experienced it on a few occasions. Sometimes you'll get lucky and it won't. Either way it's a risk.

I'm pretty sure that 95% of the people that would want to take advantage of SAM, regardless of brand affiliation or hardware employed, have zero idea they probably can't or won't go through the lengths of getting it working.

Sure, it's great as far as a feature, but let's not fool ourselves here with how limited in actual implementation it will be in the real world.
Literally anybody that has built a PC in at least the last 5 five years, or bought one from a builder that uses retail motherboards, is all UEFI. Motherboards have not defaulted to Legacy in AGES. Systems old enough to default to Legacy are too old to even make use of a high end, or even mid range GPU. So I think this is going to be a major corner case. Even the Dell systems I have worked on have been UEFI for a long long time.

So sure, there may be people that wont be able to use it. But this is not going to be some widespread issue.
 

coercitiv

Diamond Member
Jan 24, 2014
4,107
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Seems like a pointless article with no real world applicability that was put out to garner clicks.
Tom's Hardware would respectfully disagr... whatt's that? Ah, ok:

Editor's Note, Dec. 8: At the request of the publisher, we have edited this article to remove some benchmark figures taken before the Day Zero patch that may not be representative of the consumer day one experience.
 

zinfamous

No Lifer
Jul 12, 2006
104,252
18,851
136
Seems like a pointless article with no real world applicability that was put out to garner clicks.
sure, that's fair. :D

He meant this, Tom's does indeed have a way of explaining things:

Just Buy It: Why Nvidia RTX GPUs Are Worth the Money
Life is short. How many months or years do you want to wait to enjoy a new experience? [...] When you die and your whole life flashes before your eyes, how much of it do you want to not have ray tracing?
Ah, I had no idea. That might be the 2nd or 3rd Tom's article that have read/scanned, all of them from following strange internet links like a lost puppy trying to get back home.
 
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pandemonium

Golden Member
Mar 17, 2011
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Literally anybody that has built a PC in at least the last 5 five years, or bought one from a builder that uses retail motherboards, is all UEFI. Motherboards have not defaulted to Legacy in AGES. Systems old enough to default to Legacy are too old to even make use of a high end, or even mid range GPU. So I think this is going to be a major corner case. Even the Dell systems I have worked on have been UEFI for a long long time.

So sure, there may be people that wont be able to use it. But this is not going to be some widespread issue.
No, I apologize as I wasn't clear. You can not use CSM for UEFI and expect SAM to work. So there goes 95% of the machines out there.

Nevermind! Crisis averted. There's a convert tool built into Windows to update the OS drive from MBR to GPT.

 
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