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Forums - Gaming - XBONE having problems with eSRAM yield. Crazy Buttocks confirms.

walsufnir on 05 June 2013
ethomaz said:
Otakumegane said:
Can someone explain eSRAM and why it's so important all of a sudden?

It a part really important when you have a slow RAM in your system... the eSRAM or eDRAM is used to cache some data and avoid the usual bottleneck caused by low speeds issues in memory RAM... for graphics a system uses a lot of bandwidth so these embedded RAM are fast and have amazing low latency.

nVidia will use embedded RAM in the next generation of GPUs because the graphical power is increasing more than the GDDR speeds... so the RAM speeds will be a bottleneck for PC games soon... so they will use embedded RAM like MS and Nintendo do.

 

Hi and back again, old friend! Please remember that also Intel uses edram now: http://www.anandtech.com/show/6911/intels-return-to-the-dram-business-haswell-gt3e-to-integrate-128mb-edram



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thranx on 05 June 2013
kitler53 said:

if you downclock the initial shippments to achieve better yeilds you can't really fix that later.  unless MS is prepared to go the route of multi-spec consoles every xbone console will be down-speced for the entire generation.

if you stick to your orignal spec and the yeilds are currently low the intial shipments will have expensive chipsets (~chip cost = (wafer cost)/((chips per waffer)*(yeild%)) ) and probably lower stock at launch.  that cost will quickly come down in price when the yeild issues are figured out in what i'll assume is a few months time.

..or you delay until 2014.

 

I think those are the three options if the rumor is true.


thats what I was thinking too. I would rather them release this year with limited supply than to down clock anyhting or to wait another year.



Pemalite on 05 June 2013
kitler53 said:
Porcupine_I said:
kitler53 said:
wouldn't low yield just mean low shipment numbers at launch until it is figured out?

probably, but if you want high shipment numbers at launch and a downgrade of the clockspeed can fix the problems of the faulty chips, you could also go down that route.

problem is, if you do that you can't fix it later.


i was going to rebuttle with that but you beat me too it.  downclocking now would really fuck up all the games currently in developement and limit future potential (without cloud assist which if I were MS I wouldn't rely on after the always online fallout).

 

also, it's just a little air-born..

Also "Downlocking" doesn't actually fix yield all yield problems, it's a very complex problem.

Sometimes you have units on a chip that are just simply far to damaged to do anything with, not even down-clocking or throwing more voltage at the problem can solve it.
AMD, nVidia, Intel and all the other semiconductor manufacturers have a solution to that however, they disable the non-functioning portions of the chip and sell it as a cheaper product, I.E. Instead of a Quad Core, it's now a Dual Core.
They can then harvest more working parts of a wafer, again that's not viable as all the hardware across all the consoles needs to be identical.

What Microsoft should have done (If this rumour is indeed true) is throw more transisters at the problem and built more redundancy into every chip, so if a Core or a Pixel pipeline is buggered, they have some spares, I would actually be surprised if they didn't do that, unfortunatly because it drives up die-area it also drives up costs and the Xbox One's Die-Size is already rather monolothic due to the eSRAM.

Now, when a chip has allot of leakage (Should not really be a problem now on a mature 28nm manufacturing process) they simply underclock or throw more voltage at the problem, unfortunatly underclocking affects all the consoles as they have to keep the hardware the same.
Over-volting won't work either as consoles have cooling systems that are engineered for a specific TDP.

kitler53 said:


i've been told MS have mountains of money to ensure that the xbone is succesful.  wouldn't taking a high cost per chip for a couple of months until you can get better yields be worth it?  its not like this kind of issue should take years to figure out.  faced with missing this holiday (giving ps4 a head start), down specing the system (risking delays to launch games that would need to be modified for the change in specs), or taking a short term financial hit,..  i'd take the hit and hide it in MS's billion+ quarterly profits.


Nah. 28nm that the Xbox One is using is fairly mature, they would need to do a re-spin of the silicon and re-work the chips to get better yields and maybe throw more redundancy in the chips for when something doesn't function, but that costs more transisters and hence drives up costs.

However, if AMD is handling the manufacturing side, I'm pretty sure they have a deal where they only pay for working chips anyway, they might just have to fire up some more production lines to throw more chips out, it also means supply might be limited on launch, provided this rumour is true.






www.youtube.com/@Pemalite

walsufnir on 05 June 2013
ethomaz said:
walsufnir said:
sth88 said:
 

I'm no tech expert, but doesn't the X1 have more advantages over the Wii U than just GPU speeds?

 

Of course. Better CPU, better GPU, more ram, faster ram, esram is same (although probably with lower bandwidth), SHAPE-audio-chip most probably more capable than WiiU-solution, especially because of the total sound-processing-offloading to SHAPE...

Bold: No, they are not the same... Wii U uses eDRAM like 360... Xbone uses eSRAM... different techs, different performance, different results... for games the eSRAM have advantage over eDRAM because the high bandwidth (speed) and low latency.

The main differences...

1. SRAM is static while DRAM is dynamic
2. SRAM is faster compared to DRAM
3. SRAM consumes less power than DRAM
4. SRAM uses more transistors per bit of memory compared to DRAM
5. SRAM is more expensive than DRAM
6. DRAM is used in main memory while SRAM is commonly used in cache memory


Yes, generally you are right but it fulfills the same purpose :) And i actually meant the size. Of course there are differences between sram and dram :)



Lafiel on 05 June 2013
kitler53 said:


not sure i follow.  which part are you not sure about?  didn't molyneux leave MS?  what are the two possible routes? 

Yea, I ment, that MS probably don't want to burn billions of cash to ensure Xbox1 is successful. Molyneux left MS, but he said that when he was still there they had 2 concepts for the next Xbox, one was a budget machine and one a high-end machine, but both were designed to be profitable from the start.



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Porcupine_I on 05 June 2013
Lafiel said:
kitler53 said:

i've been told MS have mountains of money to ensure that the xbone is succesful.  wouldn't taking a high cost per chip for a couple of months until you can get better yields be worth it?  its not like this kind of issue should take years to figure out.  faced with missing this holiday, down specing the system, or taking a short term financial hit,..  i'd take the hit and hide it in MS's billion+ quarterly profits.

I'm not so sure about that. Molyneux said in the after show discussion for the X1 reveal at IGN that when he was still there they had 2 possible routes, but both were planned with profitability first in mind - the console as it is now he said was like a mix of both concepts, but I doubt that they dropped the aspiration to be profitable from the start.

i'm also for a while now under the impression that MS was pretty much done throwing money at the xbox business just for the sake of it.

it's just a personal hunch though, don't anyone ask for sources. Yes, i'm looking at that guy over there.



“It appeared that there had even been demonstrations to thank Big Brother for raising the chocolate ration to twenty grams a week. And only yesterday, he reflected, it had been announced that the ration was to be reduced to twenty grams a week. Was it possible that they could swallow that, after only twenty-four hours? Yes, they swallowed it.”

- George Orwell, ‘1984’

ethomaz on 05 June 2013

Now I will try to explain the difference between the PS4's APU and Xbone's APU.

PS4's APU

* 8-core Jaguar CPU
* 18 CUs GPU
* Memory controller
* 3 billion transistors
* < 300 mm² in 28nm

Xbone's APU

* 8-core Jaguar CPU
* 12 CUs GPU
* Memory controller
* 32MB eSRAM
* Fixed units: Data Moves, etc
* 5 billion transasistors
* > 400 mm² in 28nm

What define the cost and the complexity of chip? The size and how many differente parts the chip have inside it. So the Xbone's chip is huge (billion transistors > 400mm²5) and have a lot of differnt part inside it (eSRAM, Data Move, etc).

So Sony have the advantage...

In a 300mm Wafer you can produce 150 chips of the 300mm² size.. in the same 300mm Wafer you can produce only 100 chips of the 400mm² size (not real numbers... just for comparison... I used the 40nm processo... in 28nm you can produce more chips too). The cost of a Wafer is fixed... so paying the same Sony can have more chips per Wafer than Microsoft... the cost of the PS4 APU is cheaper than Xbone APU.

That not end here... you have a percentage of chips that pass in the tests for real use... so a simple and good production of chips have a margin close to 90% of the chips are GOOD... a complex and bad production (issues) have a margin below 50% of the chips are GOOD.

So using the same cost for the Wafer... I will use $10,000... and using the 80% good chips for PS4 and 50% good chips for Xbone... I can estimate these costs...

PS4: $10,000 / 120 (80% of the 150 chips are good) = $83 per APU
Xbone: $10,000 / 50 (50% of the 100 chips are good) = $200 per APU

I don't how the cost of the Wafer used to produce the chips... I can guess a value from $5,000 to $8,000 (these are the cost I remember from the 40nm process)... and I don't know the percentage of GOOD chips or the real die-size of the Xbone or PS4 APUs.

But I can say for sure... the Xbone's APU is more complex to produce end and at least 40% more expensive than the PS4's APU.

MS will never catch PS4 in APU costs in this generation... the difference is simple:

PS4: small (3 billion transistors) and simple (CPU, GPU and memory controller)
Xbone: big (5 billion transistors) and complex (CPU, GPU, memory controller, eSRAM, DataMove, etc)

The percentage of the GOOD chips per Wafer for PS4 will be always better than Xbone too.



ethomaz on 05 June 2013
walsufnir said:

Yes, generally you are right but it fulfills the same purpose :) And i actually meant the size. Of course there are differences between sram and dram :)

;)

Size you mean... 32MB? Yeah the same... and the same porpose... I agree.



kitler53 on 05 June 2013
Porcupine_I said:
Lafiel said:
kitler53 said:

i've been told MS have mountains of money to ensure that the xbone is succesful.  wouldn't taking a high cost per chip for a couple of months until you can get better yields be worth it?  its not like this kind of issue should take years to figure out.  faced with missing this holiday, down specing the system, or taking a short term financial hit,..  i'd take the hit and hide it in MS's billion+ quarterly profits.

I'm not so sure about that. Molyneux said in the after show discussion for the X1 reveal at IGN that when he was still there they had 2 possible routes, but both were planned with profitability first in mind - the console as it is now he said was like a mix of both concepts, but I doubt that they dropped the aspiration to be profitable from the start.

i'm also for a while now under the impression that MS was pretty much done throwing money at the xbox business just for the sake of it.

it's just a personal hunch though, don't anyone ask for sources. Yes, i'm looking at that guy over there.


not sure i agree with that.  1B investment in games.  400M for the NFL deal.  the live TV thing.  they seem to be investing pretty significantly, imo.



walsufnir on 05 June 2013
ethomaz said:

Now I will try to explain the difference between the PS4's APU and Xbone's APU.

PS4's APU

* 8-core Jaguar CPU
* 18 CUs GPU
* 3 billion transistors
* < 300 mm² in 28nm

Xbone's APU

* 8-core Jaguar CPU
* 12 CUs GPU
* 32MB eSRAM
* Fixed units: Data Moves, etc
* 5 billion transasistors
* > 400 mm² in 28nm

What define the cost and the complexity of chip? The size and how many differente parts the chip have inside it. So the Xbone's chip is huge (billion transistors > 400mm²5) and have a lot of differnt part inside it (eSRAM, Data Move, etc).

So Sony have the advantage...

In a 300mm Wafer you can produce 150 chips of the 300mm² size.. in the same 300mm Wafer you can produce only 100 chips of the 400mm² size (not real numbers... just for comparison... I used the 40nm processo... in 28nm you can produce more chips too). The cost of a Wafer is fixed... so paying the same Sony can have more chips per Wafer than Microsoft... the cost of the PS4 APU is cheaper than Xbone APU.

That not end here... you have a percentage of chips that pass in the tests for real use... so a simple and good production of chips have a margin close to 90% of the chips are GOOD... a complex and bad production (issues) have a margin below 50% of the chips are GOOD.

So using the same cost for the Wafer... I will use $10,000... and using the 80% good chips for PS4 and 50% good chips for Xbone... I can estimate these costs...

PS4: $10,000 / 120 (80% of the 150 chips are good) = $83 per APU
Xbone: $10,000 / 50 (50% of the 100 chips are good) = $200 per APU

I don't how the cost of the Wafer used to produce the chips... I can guess a value from $5,000 to $8,000 (these are the cost I remember from the 40nm process)... and I don't know the percentage of GOOD chips or the real die-size of the Xbone or PS4 APUs.

But I can say for sure... the Xbone's APU is more complex to produce end and at least 40% more expensive than the PS4's APU.

MS will never catch PS4 in APU costs in this generation... the difference is simple:

PS4: small (3 billion transistors) and simple (CPU, GPU and memory controller)
Xbone: big (5 billion transistors) and complex (CPU, GPU, memory controller, eSRAM, DataMove, etc)

The percentage of the GOOD chips per Wafer for PS4 will be always better than Xbone too.


You are right but it will only increase costs for MS and won't effect performance. It is like this gen: 360 is way easier than the complex ps3. But I think it is doubtable that MS will never achieve comparable outcome of wafers and I doubt that costs will always stay higher - it also depends on how much chips you order. Also keep in mind that when looking at system-performance you have to consider every part of the system. For example, SHAPE is built so that sound-processing won't need any CPU-performance. It is not like "we add everything together and we know how much it'll be better". But yes, overall $ony has an advantage also in my opinion.