• Hey, guest user. Hope you're enjoying NeoGAF! Have you considered registering for an account? Come join us and add your take to the daily discourse.

Next-Gen PS5 & XSX |OT| Console tEch threaD

Status
Not open for further replies.

Fake

Member
The problem for me is not the Nintendo Switch shortage, its those Nintendo greedy guys selling twice the price because of the shortage with a pandemic in place.
 

icerock

Member
Damn.No wonder sony doesn't want to talk about next gen yet.



Switch numbers are low because its sold out basically every where. XB1 being out sold by PS4 to the tune of 3:1 in NA, what? I dunno about his source chief.

The problem for me is not the Nintendo Switch shortage, its those Nintendo greedy guys selling twice the price because of the shortage with a pandemic in place.

That's not on Nintendo, they are constrained by supply chain and logistics issues. Blame human beings, they are shitty because they'll use any opportunity to make quick money. If you think Switch situation is bad, wait till you see some prices of PS5 on eBay in 9 months time.
 

Fake

Member
That's not on Nintendo, they are constrained by supply chain and logistics issues. Blame human beings, they are shitty because they'll use any opportunity to make quick money. If you think Switch situation is bad, wait till you see some prices of PS5 on eBay in 9 months time.
But I'm blaming human, not Nintendo.
 

Ascend

Member
That Wikipedia article is about error correction in caches. PS5's cache scrubbers are very different, they avoid the need to flush (i.e. erase) the entire GPU cache whenever the SSD is read.

Very different technologies. With this technology the GPU compute units don't need to wait to get data from memory as often.
Oh ok. Gotcha. I don't think it's about not waiting to get data from memory as often though, but rather decreasing wait time between cycles. You'll wait lightly more often but for much shorter periods of time, so to speak. But thanks for the clarification.
 

BluRayHiDef

Banned
The PS5 TE is not a standard CU, it's generally based on a CU architecture, for instance, it has 64 SU, but it is not an RND2 CU. When Sony or MS makes a GPU, they have no way of knowing in advance which CU will be defective so as a result, they have no idea which 4 CU they will disable, it's different for each APU that gets made. So Sony needs all 40 CU to be identical in order for the active 36 CU to be identical, that's why TE can't be one of the 40 CU. If anything, the TE will probably add more power to the PS5 because it's programable, which means some developers will "hack" it and use it for other purposes.

If it is a separate and totally unique component relative to the standard CUs, then how can Sony assure tolerable yield rates for the APU, since the odds of producing an APU with one fully functional Tempest Engine out of only one Tempest Engine would be low? Do you suppose that there are redundant Tempest Engines in the APU, so that the odd of producing an APU with at least one fully functional Tempest Engine would be high?
 

FranXico

Member
I am in agreement, however didn't Cerny say it will contain no GPU properties like a CU? That it's more an SPU like in the Cell, which then I suppose could be used for other things besides audio if they are allowed to. SPUs were able to do adaptive tesselation as an example.
He said something along the lines that it was based on a CU to "benefit from GPU parallelism", but differed in some ways such as, for example, no caching, in order to resemble a CELL SPU more and make it more appropriate to audio than an actual GPU (this last comment should tell you that it's separate from the 36 active GPU CUs, btw).
 
Last edited:

DaGwaphics

Member
Edit : I see you’ve added a bit about ssd sequential vs random access speed differences. I’ve never heard of this applying to ssd. It certainly doesn’t make sense without ssd having mechanical restrictions, but I’m no expert.

Manufacturers have taken to only posting max numbers and not providing a full performance breakdown. While there are no seeks, there is still the issue of the max #s being based on requests that can fully saturate the pipeline for the duration of the test. This is easy to do when testing against a large file that is large enough, but not too large to fill the dram cache. If you run a standard random read test, say 4kb random reads spread over a section of storage larger than the dram cache, speeds will plummet. This is similar to a internet bandwidth test, testing with one large file will saturate your connection offering the best result, while thousands of tiny files will not fully utilize your connection.
 

Shmunter

Member
Manufacturers have taken to only posting max numbers and not providing a full performance breakdown. While there are no seeks, there is still the issue of the max #s being based on requests that can fully saturate the pipeline for the duration of the test. This is easy to do when testing against a large file that is large enough, but not too large to fill the dram cache. If you run a standard random read test, say 4kb random reads spread over a section of storage larger than the dram cache, speeds will plummet. This is similar to a internet bandwidth test, testing with one large file will saturate your connection offering the best result, while thousands of tiny files will not fully utilize your connection.
I can’t argue the ssd stuff because I simply don’t know enough. But the internet downloading is not strictly comparable, there are overheads for data over the net. 10 small ones have 10x the packaging overhead vs 1x bigger one. And yes I also appreciate packet sizing matters.

Apart from that, Sony doing 12 priority channels on the ssd and all this wiz bang stuff could be exactly the motivation to alleviate traditional shortcomings of the tech.

Anyway, convo out of my depth lol. All I said is PS5 ssd has ddr3 speed which checks out if reviewing speed metrics. Or at least that’s what I intended.
 
Last edited:

joe_zazen

Member
That Switch shortage is really hurting those numbers from Nintendo. I'm surprised at how badly the X1 is doing in comparison to it's direct competitor.

.

nintendo keeps very low inventories to minimise expenses. It is hurting them now...and my SO. Shes really bummed now that she cant play new AC. Not bummed enogh to pay $600 tho, lol.

we’ll prolly end up getting a light and an og later. Nintendo wins.
 
Last edited:
The problem for me is not the Nintendo Switch shortage, its those Nintendo greedy guys selling twice the price because of the shortage with a pandemic in place.

Scalpers are taking advantage of everything during this pandemic. It's really sickening to see them hoard medical supplies and higenic products. Heck people have to entertain themselves during their isolation at reasonable prices. Scalpers don't let them do that.
 
If DirectStorage is only an API, how do they magically get performance of multiple Zen cores? From your own link;

Microsoft’s Goossen told Digitial Foundry that doing decompression on the 4K textures to match the speed of the SSD rate would have consumed three Zen 2 CPU cores, plus an additional two more just for the I/O overhead. With DirectStorage, Microsoft reduced that down to just a tenth of one core. All that CPU power can now be repurposed for other things.

DirectStorage is an API (via News.Xbox.com: https://news.xbox.com/en-us/2020/03/16/xbox-series-x-glossary/):
DirectStorage – DirectStorage is an all new I/O system designed specifically for gaming to unleash the full performance of the SSD and hardware decompression. It is one of the components that comprise the Xbox Velocity Architecture. Modern games perform asset streaming in the background to continuously load the next parts of the world while you play, and DirectStorage can reduce the CPU overhead for these I/O operations from multiple cores to taking just a small fraction of a single core; thereby freeing considerable CPU power for the game to spend on areas like better physics or more NPCs in a scene. This newest member of the DirectX family is being introduced with Xbox Series X and we plan to bring it to Windows as well.

The hardware decompression unit is a different feature/component that is equivalent to multiple Zen cores.
 
Last edited:

DaGwaphics

Member
I can’t argue the ssd stuff because I simply don’t know enough. But the internet downloading is not strictly comparable, there are overheads for data over the net. 10 small ones have 10x the packaging overhead vs 1x bigger one. And yes I also appreciate packet sizing matters.

Apart from that, Sony doing 12 priority channels on the ssd and all this wiz bang stuff could be exactly the motivation to alleviate traditional shortcomings of the tech.

Anyway, convo out of my depth lol. All I said is PS5 ssd has ddr3 speed which checks out if reviewing speed metrics

Here's a link that will shed some light on these numbers. Note this is just the first result, not the most recent. But it will show why SSDs aren't RAM.

 

Thirty7ven

Banned
SSDs aren’t supposed to be ram, but if you remove the bottlenecks you won’t need as much RAM because you can switch data quickly enough in the RAM itself. It’s why we don’t need such a big increase in RAM, why data streaming is only going to become even more important, and it’s why these SSDs are a biG deal. It’s not like we have on pc, because there’s many bottlenecks there (which will be removed as well in the near future).

It’s hard to grasp for some folks, even people like Alex from DF, but thankfully devs will know what to do with it as it was their main request.
 

xool

Member
higher throughput from decompression unit (22GB/s vs 6GB/s),
That 22GB is theoretical peak of the hardware. Probably only obtainable if the texture is 1GB of zeros... The real number is 9.6
PS5 ssd is essentially 800 terrabytes of DDR3
800TB 👍
My authority has cache scrubbers, when refuted I don't have to wait for the next dubious source, just scrubbed and loaded up with some more juicy FUD.
Q. Why aren't people talking about the cache scrubbers secret sauce ?
A. Nobody know what they fuck they are or do.
 
Putting all the transfer speeds aside, there is one other important aspect here. You can read from and write to RAM bit for bit. For SSDs, you can't. You can only read pages, and only write to blocks.


RAM is cleared and reloaded frequently depending on the assets that will be needed in the near future. An SSD would not be able to do this, because they are by default hampered in terms of writing.


If DirectStorage is only an API, how do they magically get performance of multiple Zen cores? From your own link;

Microsoft’s Goossen told Digitial Foundry that doing decompression on the 4K textures to match the speed of the SSD rate would have consumed three Zen 2 CPU cores, plus an additional two more just for the I/O overhead. With DirectStorage, Microsoft reduced that down to just a tenth of one core. All that CPU power can now be repurposed for other things.

"This newest member of the DirectX family is being introduced with Xbox Series X and we plan to bring it to Windows as well."
This is coming straight from Xbox's own glossary of terms under the term DirectStorage, what else do you need other than words coming from Microsoft's mouth? The newest member of the DirectX family. DirectX isn't a component, it's an API and DirectStorage will be one of its components once the Series X launches. It will find its way on pc sometime later down the line. I don't think i need to say more.
 
Last edited:

DeepEnigma

Gold Member
SSDs aren’t supposed to be ram, but if you remove the bottlenecks you won’t need as much RAM because you can switch data quickly enough in the RAM itself. It’s why we don’t need such a big increase in RAM, why data streaming is only going to become even more important, and it’s why these SSDs are a biG deal. It’s not like we have on pc, because there’s many bottlenecks there (which will be removed as well in the near future).

It’s hard to grasp for some folks, even people like Alex from DF, but thankfully devs will know what to do with it as it was their main request.

200.gif


This is short, Laymen's, and to the point.

Something that people who allow their fanaticism and false allegiance lose sight of. This benefits ALL platforms going forward, especially the PC arena. Fighting it makes one look painfully obtuse.
 

FranXico

Member
In the coming years, APUs are going to take over PC design and are definitely going to use XboxSX and PS5 style I/O pipeline enhancements one way or another.
PCMR should be thanking console peasants for what they are going to make economically feasible this holiday season.
 

Shmunter

Member
That 22GB is theoretical peak of the hardware. Probably only obtainable if the texture is 1GB of zeros... The real number is 9.6

800TB 👍

Q. Why aren't people talking about the cache scrubbers secret sauce ?
A. Nobody know what they fuck they are or do.
According to Cerney cache scrubbers allow the deletion of discrete parts of the cache instead of all of it. The cache normally would all get blown away unnecessarily as soon as ram gets altered by streaming in new data from ssd. Cache scrubbers will only delete necessary parts of the cache where underlying ram gets changed. Obviously cache is the fastest part of the memory system so you want to preserve it to keep peak performance.
 

xool

Member
According to Cerney cache scrubbers allow the deletion of discrete parts of the cache instead of all of it. The cache normally would all get blown away unnecessarily as soon as ram gets altered by streaming in new data from ssd. Cache scrubbers will only delete necessary parts of the cache where underlying ram gets changed. Obviously cache is the fastest part of the memory system so you want to preserve it to keep peak performance.
I thought cache gets changed/overwritten when GPU access memory not in cache - .. so it'll get overwritten anyway ?

When main memory gets changed by SSD the GPU cache scrubber is informed and marks all data in that range as "old" ?? - maybe .. I don't feel this was explained that well in the talk
 

Neo Blaster

Member
I want to know something

How is the Playstation 5's SSD a "gamechanger" when all of the multiplatform games will be targeting HDD?
We'll only see a few improvements, the main one being load times, but then again, comparing SSD load times is like comparing bullet speeds.
The only games to take full advantage of PS5 ludicrously fast SSD are the First Party exclusives, which are going to be totally amazing.
At the end of the day, games are going to look better on the SXS and load faster on the PS5. Both consoles are going to be amazing.
So, for you BOTH SSDs are useless due to the lowest common denominator HDDs? Don't forget SX will be much more affected by this problem cause even its first party games will have to run on old hardware for some time, while PS5 first party games can thrive from the start.

For multis, your point can be considered while third parties make crossgen and PC titles which are bound by mechanical HDDs, but you're ignoring the bar has been raised by the consoles. Sometime in the next gen, devs will begin to mandate SSDs for PC configurations and stop making crossgen games. That's the only way game design can evolve.
 

Ascend

Member
"This newest member of the DirectX family is being introduced with Xbox Series X and we plan to bring it to Windows as well."
This is coming straight from Xbox's own glossary of terms under the term DirectStorage, what else do you need other than words coming from Microsoft's mouth? The newest member of the DirectX family. DirectX isn't a component, it's an API and DirectStorage will be one of its components once the Series X launches. It will find its way on pc sometime later down the line. I don't think i need to say more.
If you say so... I still have questions. Like... The one I already asked. How can only an API change reduce CPU performance from 3 cores to less than 1/10th of a core? Where they simply lazy all these years? Why wasn't this done earlier on the Xbox One which is known to be extremely underpowered in the CPU department?
There is something else going on here.

Don't forget SX will be much more affected by this problem cause even its first party games will have to run on old hardware for some time, while PS5 first party games can thrive from the start.
They can, but I doubt they will use it from the start. Most likely it will take at least two years into the cycle before we start seeing games that truly utilize the SSD speeds.
 
Last edited:

ethomaz

Banned
The thing is any one of the CUs from SA's can be disabled, they can't predict were the defects will hit that's why im not sold on the idea, plus TE is a different design. Besides TE is tiny it wouldn't take much space at all.
But idk could happen.
You don’t choose where to disable them unless the 40 ones are usable.
You disable the defective ones and that means there 4 defectives can be even in the same SA.
It is random.

That is how you increase the yields with redundant units.
 
Last edited:
If you say so... I still have questions. Like... The one I already asked. How can only an API change reduce CPU performance from 3 cores to less than 1/10th of a core? Where they simply lazy all these years? Why wasn't this done earlier on the Xbox One which is known to be extremely underpowered in the CPU department?
There is something else going on here.


They can, but I doubt they will use it from the start.
Afaik api's can help reduce overhead to a certain extent speeding up certain workloads depending on how they're implemented and utilised. One game engine might use it in a different way than another. No two engines are ever alike, especially proprietary ones coming from first party studios ,which are bound to use the api itself and its features in a much more streamlined manner since they're supposed to be the ones more familiar with the architecture itself compared to third party studios which could approach it in a different manner. You'll notice the effects of DirectStorage more on first party games than third party games.
 
Last edited:

Ascend

Member
What makes you think that?
Let me rephrase it a little bit. They will use the SSD speeds, but it won't be anywhere near optimal. In the beginning I expect developers to simply throw everything at the SSDs with little optimization. They have much more leeway compared to before after all. One of the things with too much freedom is that efficiency and optimization goes out the window.
Imagine for a second if the PS3 had come out with 16GB of RAM. The last thing you're going to optimize for is the RAM, because the bottleneck is everywhere else.
A similar thing will happen in the beginning of the PS5/XSX gen. Developers are currently used to running games from extremely slow hard drives. The SSDs provide such fast speeds that their optimization will not go into the SSDs for now, but into the rest of the system. And since games take a few years to develop, the games that really utilize the SSDs efficiently will release in about two years, which is actually quite short. If compared to the PS3 Cell, it took way longer than 2 years to see games that actually took real advantage of it.
 
Let me rephrase it a little bit. They will use the SSD speeds, but it won't be anywhere near optimal. In the beginning I expect developers to simply throw everything at the SSDs with little optimization. They have much more leeway compared to before after all. One of the things with too much freedom is that efficiency and optimization goes out the window.
Imagine for a second if the PS3 had come out with 16GB of RAM. The last thing you're going to optimize for is the RAM, because the bottleneck is everywhere else.
A similar thing will happen in the beginning of the PS5/XSX gen. Developers are currently used to running games from extremely slow hard drives. The SSDs provide such fast speeds that their optimization will not go into the SSDs for now, but into the rest of the system. And since games take a few years to develop, the games that really utilize the SSDs efficiently will release in about two years, which is actually quite short. If compared to the PS3 Cell, it took way longer than 2 years to see games that actually took real advantage of it.

That's just complete conjecture and doesn't really make sense at all

I mean, why exactly would Spiderman 2 or HZD 2, which we can assume both will be out by 2021/2022, take this inefficient route? And God of War 2 or Days Gone won't? They're not going to be rushing these things.
 

DaGwaphics

Member
That's just complete conjecture and doesn't really make sense at all

I mean, why exactly would Spiderman 2 or HZD 2, which we can assume both will be out by 2021/2022, take this inefficient route? And God of War 2 or Days Gone won't? They're not going to be rushing these things.

I think first parties will work to maximize both systems as quickly as possible. Third parties are in a different position. Most of those profitable $60 game sales are in console, but the PC market is still worth a good chunk of change (the mid tier being the most profitable). They could go all-in on the SSD and just forget the majority of the PC market, or they could build a game that can run on a lower standard and have all the markets covered. I know where I'm putting my money. Even if new technology hit the PC space tomorrow (better APUs, GPUs, SSDs, Memory, etc.), it will take years for that tech to become the average baseline for PC.
 
Last edited:
I think first parties will work to maximize both systems as quickly as possible. Third parties are in a different position. Most of those profitable $60 game sales are in console, but the PC market is still worth a good chunk of change (the mid tier being the most profitable). They could go all-in on the SSD and just forget the majority of the PC market, or they could build a game that can run on a lower standard and have all the markets covered. I know where I'm putting my money. Even if new technology hit the PC space tomorrow (better APUs, GPUs, SSDs, Memory, etc.), it will take years for that tech to become the average baseline for PC.

I simply don't believe that based on precedence. If the pubs were fine making current-gen exclusive and ditching the PS3/360 install, base (where PC gaming wasn't even as valued by them as it is now), then I fully expect them to do the same next-gen.
 

SonGoku

Member
Really? Ok...
Yes, completely different concepts. The 6 priority levels tailored for gaming Cerny mentioned are in the memory controller and have no correlation with nand chips
Then why did he compared it with HDD's sequential speeds? Doesn't make any sense...
Do we know for sure random reads have a significant impact in gaming, and how frequent are they? keep in mind they also implemented customizations to minimize its impact
4K random reads benchmarks were posted earlier to show how SSD throughput drops but what about current consoles laptop hdds? In 4k random read benchmarks the average 5400rpm drive scores 80 iops or 0.3 MB/s. I don't think these tests are indicative of gaming workloads

The PS5 TE is not a standard CU, it's generally based on a CU architecture, for instance, it has 64 SU, but it is not an RND2 CU. When Sony or MS makes a GPU, they have no way of knowing in advance which CU will be defective so as a result, they have no idea which 4 CU they will disable, it's different for each APU that gets made. So Sony needs all 40 CU to be identical in order for the active 36 CU to be identical, that's why TE can't be one of the 40 CU. If anything, the TE will probably add more power to the PS5 because it's programable, which means some developers will "hack" it and use it for other purposes.
Thanks for breaking it down, I know TE used a CU as its frame but they redesigned in such a way the micro architecture closely resembles a SPU. As such TE wouldn't be able to dub as a traditional CU to work in tandem with other CUs since its different on the micro-architecture level, it wouldn't contribute to the advertised 10.27TF either
I am in agreement, however didn't Cerny say it will contain no GPU properties like a CU? That it's more an SPU like in the Cell, which then I suppose could be used for other things besides audio if they are allowed to. SPUs were able to do adaptive tesselation as an example.
True but remember he said its main purpose its 3D audio and it can help with other audio related calculations since it excels at them
I don't think it would be worth it to sacrifice audio (defeating the purpose of TE) to offload visual calculations with only a fraction of GPU power
That 22GB is theoretical peak of the hardware. Probably only obtainable if the texture is 1GB of zeros... The real number is 9.6
Agreed, was merely comparing the peak capabilities of the decompression units.
 
Last edited:

xool

Member
I think first parties will work to maximize both systems as quickly as possible. Third parties are in a different position. Most of those profitable $60 game sales are in console, but the PC market is still worth a good chunk of change (the mid tier being the most profitable). They could go all-in on the SSD and just forget the majority of the PC market, or they could build a game that can run on a lower standard and have all the markets covered. I know where I'm putting my money. Even if new technology hit the PC space tomorrow (better APUs, GPUs, SSDs, Memory, etc.), it will take years for that tech to become the average baseline for PC.

I think M2 SSD / PCiE 3.0 SSD drives will become recommended mimimum specs for PC games very quickly once next gen gets going. They only need the drive for the games, so it doesn't need to be huge capacity. It's like a $50-100 upgrade to reach Series X performance. Peanuts for PC_Master_Race.

They pay more for Keyboards and Mice..
 
Last edited:

DeepEnigma

Gold Member
Yes, completely different concepts. The 6 priority levels tailored for gaming Cerny mentioned are in the memory controller and have no correlation with nand chips

Do we know for sure random reads have a significant impact in gaming, and how frequent are they? keep in mind they also implemented customizations to minimize its impact
4K random reads benchmarks were posted earlier to show how SSD throughput drops but what about current consoles laptop hdds? In 4k random read benchmarks the average 5400rpm drive scores 80 iops or 0.3 MB/s. I don't think these tests are indicative of gaming workloads


Thanks for breaking it down, I know TE used a CU as its frame but they redesigned in such a way the micro architecture closely resembles a SPU. As such TE wouldn't be able to dub as a traditional CU to work in tandem with other CUs since its different on the micro-architecture level, it wouldn't contribute to the advertised 10.27TF either

True but remember he said its main purpose its 3D audio and it can help with other audio related calculations since it excels at them
I don't think it would be worth it to sacrifice audio (defeating the purpose of TE) to offload visual calculations with only a fraction of GPU power

Agreed, was merely comparing the peak capabilities of the decompression units.

Don’t get me wrong, I think it’ll be used strictly for audio as well, and will excel at it. Also offloads the audio from the GPU resources.
 

xool

Member
Damn.No wonder sony doesn't want to talk about next gen yet.



Is this a weekly or monthly total. ~300,000 per month ~= 3.6m per year ignoring seasons, but 14.4 m if weekly - seems high. Is the data confirmed legit.

Xbox still getting owned though.

[edit] - Doubt - PS4 outselling Switch in Japan - why?? this aint right ?
 
Last edited:
Is this a weekly or monthly total. ~300,000 per month ~= 3.6m per year ignoring seasons, but 14.4 m if weekly - seems high. Is the data confirmed legit.

Xbox still getting owned though.

[edit] - Doubt - PS4 outselling Switch in Japan - why?? this aint right ?
Switch is having shortages. And media create confirmed that weekly number for Japan and this is correct . These are weekly numbers
 

Neo Blaster

Member
Is this a weekly or monthly total. ~300,000 per month ~= 3.6m per year ignoring seasons, but 14.4 m if weekly - seems high. Is the data confirmed legit.

Xbox still getting owned though.

[edit] - Doubt - PS4 outselling Switch in Japan - why?? this aint right ?
It's a weekly chart, so PS4 could be selling more than 1kk this month thanks to the quarantine. Switch is in shortage everywhere, Nintendo's low unit stock policy is surely hurting them now.
 
Last edited:

Fake

Member
[edit] - Doubt - PS4 outselling Switch in Japan - why?? this aint right ?
FF7R.
 
Last edited:

DrKeo

Member
I am in agreement, however didn't Cerny say it will contain no GPU properties like a CU? That it's more an SPU like in the Cell, which then I suppose could be used for other things besides audio if they are allowed to. SPUs were able to do adaptive tesselation as an example.
Yes, TE is programable so developers might use it for other things just like they did on PS3 with the SPUs.

If it is a separate and totally unique component relative to the standard CUs, then how can Sony assure tolerable yield rates for the APU, since the odds of producing an APU with one fully functional Tempest Engine out of only one Tempest Engine would be low? Do you suppose that there are redundant Tempest Engines in the APU, so that the odd of producing an APU with at least one fully functional Tempest Engine would be high?
Not all parts of the GPU suffer from fail rates as high as CUs. Cache for instance has a very hight tolerance for manufacturing defects. A very high percentage of PS5 consoles will have 40 fully functional CUs and most of the PS5 consoles with defective CUs will only have one defective CU so even if the TE has the exact same fail rate as a CU, it will be much lower than 2.5% out of usable PS5 APUs. That’s why GPU yields go up the less CUs a GPU has, a single CU has a very low fail rate but when you have 40, there is a defective CU in a high percentage of the GPUs.

You don’t choose where to disable them unless the 40 ones are usable.
You disable the defective ones and that means there 4 defectives can be even in the same SA.
It is random.

That is how you increase the yields with redundant units.
If all 4 defective CUs are in the same SA the GPU isn’t usable. In RDNA 1 and 2 (and GCN too) the SEs have to remain balanced, so if you deactivate a CU in one, you have to deactivate one in the other. If all 4 defective CUs are in the same SA, you need at least 8 deactivated CUs in order to make the GPU pass certification and statistically you actually need to disable more more than 12 CUs.
 
Last edited:

ethomaz

Banned
Yes, TE is programable so developers might use it for other things just like they did on PS3 with the SPUs.


Not all parts of the GPU suffer from fail rates as high as CUs. Cache for instance has a very hight tolerance for manufacturing defects. A very high percentage of PS5 consoles will have 40 fully functional CUs and most of the PS5 consoles with defective CUs will only have one defective CU so even if the TE has the exact same fail rate as a CU, it will be much lower than 2.5% out of usable PS5 APUs. That’s why GPU yields go up the less CUs a GPU has, a single CU has a very low fail rate but when you have 40, there is a defective CU in a high percentage of the GPUs.


If all 4 defective CUs are in the same SA the GPU isn’t usable. In RDNA 1 and 2 (and GCN too) the SEs have the remain balanced, so if you deactivate a CU in one, you have to deactivate one in the other. If all 4 defective CUs are in the same SA, you need at least 8 deactivated CUs in order to make the GPU pass certification and statistically you actually need to disable more more than 12 CUs.
Of course it is... there is RX 5500 with all disabled CUs in the same SA... one SA with 14CUs and the other with 1

There is no point in use redundant CUs to increase yields if only these with 1 CU defect in each SA fits.

PS5 will probably have units with the 10, 10, 10 and 6 CUs per SA.

Edit - Fixed the 20 lol
 
Last edited:
Status
Not open for further replies.
Top Bottom