Question Speculation: RDNA3 + CDNA2 Architectures Thread

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uzzi38

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maddie

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For N31 it makes sense. 5x 64bit MCDs is 320 and 6x 64bit MCDs is 384. That is an advantage of the chiplet design. if you are going to cut the memory bus you use less silicon.

I presume the GDDR6X is just a typo.
Do you think it's a planned 5 MCD or a failed 6 MCD bond? If the latter, then no saving. We have seen a 2 core die 7600X exists. which is very strange. The present bond failure rate might be higher than assumed.
 

Saylick

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Ah dang, how did I miss this one in reading the Twitter thread. After 10 years of using a hardware scheduler (AMD transitioned to it with GCN), it looks like software-based scheduling is back on the menu for RDNA 3, likely for the sake of increasing perf/W and perf/A. Of course, this approach requires more software development work on the compiler but perhaps it will pan out well for AMD given they have far more resources today than before. Also, the side bonus is that compilers can get optimized over time, so FineWine is more of a possibility.

 

Aapje

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Mar 21, 2022
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@maddie

They don't need huge bonding failures to cut the card this way. One less MCD is still a saving, compared to zero savings for lasering a perfectly good part of the die.

@Saylick

A lot of 'fine wine' was AMD simply lacking the development capacity to use their hardware fully at release and only unlocking the actual power of the card much later. So less fine wine is generally better.
 

Saylick

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@Saylick

A lot of 'fine wine' was AMD simply lacking the development capacity to use their hardware fully at release and only unlocking the actual power of the card much later. So less fine wine is generally better.
Yeah, that's a good point. Given what I've read, AMD have been putting in the time and effort to make sure the launch drivers are as polished as they can be, so the wine may already be fine. I suppose one negative of a SW based scheduler is that if AMD ever change the WGP too much, development of the optimizations for older architectures may fall by the wayside, similar to what happened with Kepler after Maxwell launched.
 

Tuna-Fish

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Do you think it's a planned 5 MCD or a failed 6 MCD bond?

Both, obviously. How large proportion is "planned" of course depends on their yields for the step. I'd assume it would start with a lot higher failure rate and then over time the ratio of "true" 5-MCD parts would creep up.

We will know that failure is high if they bring products with the larger GCD and 4 MCDs to market.

If the latter, then no saving.

Being able to sell harvested products is absolutely going to save money.
 

Timorous

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Oct 27, 2008
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Do you think it's a planned 5 MCD or a failed 6 MCD bond? If the latter, then no saving. We have seen a 2 core die 7600X exists. which is very strange. The present bond failure rate might be higher than assumed.

Both as Tuna says but i expect the majority will be 5 MCDs.
 

Kaluan

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Jan 4, 2022
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We will know that failure is high if they bring products with the larger GCD and 4 MCDs to market.
Hm, I've already speculated a mid-gen refresh consisting of a N31-based RX 7850 XT may have 4-5 MCDs (and maybe 24Gbps GDDR6).

IDK, it's way too early to speculate about tertiary failure/salvages on advanced packaging, "next gen" is barely off the ground. But considering this is the general trend for chip industries, it will eventually be thing product planners and analysts have to openly account for.
 

RnR_au

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Have to say that I only play single player games but I have never though to myself:
"If only this added more fake frames between each real one, things would look smoother."
The only single player game I touch nowadays is from 2005, so the frames are already high enough not to matter for me and it sounds like its the same for you :)

But I can see the value that some people would attach to smoother game play which still preserving high detail and resolution.

I don't understand the labeling of 'fake' frames as if they are somehow inherently bad. Are we going to call out 'fake' pixels too? Ridicule usage of FSR perhaps?
 

Shmee

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This could be the time when AMD does better in the GPU market than it does in the CPU market.
It is certainly possible, as it has happened before. It was like this for most of GCN before Zen was out, IMO. The difference now, is that the AMD CPUs are already doing quite well, whether talking AM4 or AM5.
 

eek2121

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This could be the time when AMD does better in the GPU market than it does in the CPU market.

Doubt it. Too many folks equate AMD with having slow GPUs with buggy drivers, which is a shame, because next gen sounds like it is going to lay the smackdown on NVIDIA.

AMD could charge similar prices to last year and still wouldn’t sell as many units as NVIDIA.
 

Kepler_L2

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Do you think it's a planned 5 MCD or a failed 6 MCD bond? If the latter, then no saving. We have seen a 2 core die 7600X exists. which is very strange. The present bond failure rate might be higher than assumed.
Most will probably be 5 MCD, but no doubt there will be some 6 MCD with a failed bond, as well as 4 full MCD + 2 half disabled MCD.
 

Stuka87

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Dec 10, 2010
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Any predictions on how AMD will compare on ray tracing this generation?

Most were thinking below Ada, maybe a bit above Ampere.

But that was before some of this more recent info came out in regards to ray coherence sorting. So, not sure where the current guesses are. Guess we will find out in a few days.
 

Saylick

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Sep 10, 2012
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Any predictions on how AMD will compare on ray tracing this generation?

I think anywhere between 2x to 3x hybrid RT performance over N21 is fair game. Who knows what the average might be across 50 titles. Won't know until it gets benched.

Most were thinking below Ada, maybe a bit above Ampere.

But that was before some of this more recent info came out in regards to ray coherence sorting. So, not sure where the current guesses are. Guess we will find out in a few days.
AMD patent for Compute Unit Sorting for Reduced Divergence: https://www.freepatentsonline.com/20200409695.pdf
 
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maddie

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Jul 18, 2010
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Most will probably be 5 MCD, but no doubt there will be some 6 MCD with a failed bond, as well as 4 full MCD + 2 half disabled MCD.
Now that is a possibility I had not thought of, I/2 MCDs. I suppose we could tell by the placement of the memory chips on the PCB. A 1/2 MCD using (1) 2GB die is a giveaway.

edit:
I'm assuming that the MCDs use adjacent paired memory chips.
 

Thunder 57

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Aug 19, 2007
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Have to say that I only play single player games but I have never though to myself:
"If only this added more fake frames between each real one, things would look smoother."
I really see zero or less value in DLSS 3.0 - certainly at the moment with the artifacts and in the future too unless the DL AI becomes truly sentient and plays the game for me. And even the, if I wanted to watch gaming footage I could go to youtube!

Imagine being the one trying to market DLSS 3.

Fake Frames! "The way it's meant to be played"!
 

SteveGrabowski

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Oct 20, 2014
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Doubt it. Too many folks equate AMD with having slow GPUs with buggy drivers, which is a shame, because next gen sounds like it is going to lay the smackdown on NVIDIA.

AMD could charge similar prices to last year and still wouldn’t sell as many units as NVIDIA.

God I hope we get a nice 1440p card at 150W for ~$300 or so.
 

Carfax83

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Nov 1, 2010
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Even though I have always leaned strongly towards Nvidia graphics cards, I sincerely hope that RDNA3 is powerful enough to put a smackdown on Nvidia this cycle. Nvidia has too much power in the GPU market and they need to be taken down a few notches. RDNA2 came close, but it's ray tracing performance was definitely an Achilles heel compared to Ampere.

My biggest concern with RDNA3 is ray tracing. Nvidia has such a large lead, that even if RDNA3 doubles ray tracing performance, they will still be behind Nvidia in the majority of ray tracing capable titles. They need to triple ray traced performance to really be on par with Nvidia and that's a tall order.

RTX 4090 is out of stock everywhere and I don't feel like paying scalper prices on eBay so I can enjoy gaming at 4K when I build my new computer, so I'm hoping and praying that AMD delivers in a big way.

If not, I may just buy a used RTX 3090 Ti on eBay even though it's nowhere near as good as an RTX 4090 for tackling 4K. This kind of thing is almost enough to turn me into a console gamer :D
 
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