General external expansion discussion? *spawn*

[Deleted member 11852]

Unfortunately, unless things have changed smaller node NAND cells have significantly lower lifespan. Not a little significant but a lot significant.

You mentioned this before and I forgot to come back on it. Is there a link that details this? This sounds like some early manufacturing issue that occurred once or twice and has since been resolved because ther is no technical reason for this that I can think of.

 

[JPT]

Everybody is talking like it will not be possible to get an expansion drive for the ps5 before the end of times. But Sony are delivering a 825GB drive with the console. And the price for that console is 499/399 including the drive.
So I think its within the realm of possibility that during 2021 we will see viable options to buy. In regards to price and size.
I seriously doubt Sony just went of the rails and did something super weird and not look at what will be available down the road, when you look at the approach they have had before with PS3 and PS4.

 

[Deleted member 13524]

Cerny also said the expansion drive will need to have 7GB/s reading speeds to match the latency optimization provided by the PS5 SSD's additional priority lanes, so I guess that's how they'll whitelist the drives.


The Samsung 980 Pro already does 7GB/s, by the way. People will probably be able to upgrade the PS5's storage on day one, though why they would choose to do so is beyond me.

 

[iroboto]

Cerny also said the expansion drive will need to have 7GB/s reading speeds to match the latency optimization provided by the PS5 SSD's additional priority lanes, so I guess that's how they'll whitelist the drives.


The Samsung 980 Pro already does 7GB/s, by the way. People will probably be able to upgrade the PS5's storage on day one, though why they would choose to do so is beyond me.

It may throttle below 5.5 and writes are well below 5.5 I have a graph of it somewhere above.
This is what I’m unsure of. We have no idea what the actual spec for performance Ps5 requires.

 

[goonergaz]

Without knowing the spec, how would you know that?
I'm not saying you're wrong, but this isn't 100% lock.

Below is the 980 performance over time with temperature.
It didn't even last 110 seconds before it started throttling. And it hit a massive drop further down to below 2000 GB/s.
This is what I don't know. This is why I have reservations. 70-90 degrees C, is pretty crazy high to be in a PS5. I don't know what the write requirements are either, because this is really low once its starts throttling.

https://www.tomshardware.com/reviews/samsung-980-pro-m-2-nvme-ssd-review

Why on earth would the PS5 SSD need to run for such a length of time!? A whole game can load in a few seconds- you are using an impossible scenario to prove a point. To put it another way, how much data can be moved in 110 seconds? How many game will need to do that?

The SSD is there to supplement the RAM and help get data quicker to the GPU - we’re not talking of any scenario where a game is constantly streaming.

And who knows if the PS5 has a special caddy that you fit the SSD into and then slot into the PS5, not unlike the PS4 but one that has the ability to cool the SSD.

Also it’s a given technology gets cheaper and as such that will pass directly to the consumer and not be controlled by MS and passed on when and where they see fit.

This SSD concern trolling is just like the variable clock speed BS IMO.

 

[iroboto]

Why on earth would the PS5 SSD need to run for such a length of time!? A whole game can load in a few seconds- you are using an impossible scenario to prove a point. To put it another way, how much data can be moved in 110 seconds? How many game will need to do that?

The SSD is there to supplement the RAM and help get data quicker to the GPU - we’re not talking of any scenario where a game is constantly streaming.

And who knows if the PS5 has a special caddy that you fit the SSD into and then slot into the PS5, not unlike the PS4 but one that has the ability to cook the SSD.

UE5 demo has a 768MB streaming pool.
Which means all those textures you saw, on screen at once, was held in a pool of less than 1GB. the remaining memory was used for other things. If you do that, then obviously the SSD is responsible for moving data into that pool all the time.

 

[goonergaz]

UE5 demo has a 768MB streaming pool.
Which means all those textures you saw, on screen at once, was held in a pool of less than 1GB. the remaining memory was used for other things. If you do that, then obviously the SSD is responsible for moving data into that pool all the time.

Where is this info? How much data is being moved and how often? In a real game (IIRC) Cerny mentioned 2gb being loaded as a player turned in half a second, so that’s implying a complete view is at a cost of 2gb, if a player is moving through a world and the data is constantly steaming you're essentially talking about a worse case scenario which devs won’t have the assets to stream for a whole 10 hour game to prove a point.

Just because the PS5 can doesn’t mean it will, how long until devs are maximising the SSD? And even then the game is limited in assets to mean a game will be constantly streaming.

 

[iroboto]

Where is this info? How much data is being moved and how often? In a real game (IIRC) Cerny mentioned 2gb being loaded as a player turned in half a second, so that’s implying a complete view is at a cost of 2gb, if a player is moving through a world and the data is constantly steaming you're essentially talking about a worse case scenario which devs won’t have the assets to stream for a whole 10 hour game to prove a point.

Just because the PS5 can doesn’t mean it will, how long until devs are maximising the SSD? And even then the game is limited in assets to mean a game will be constantly streaming.

https://wccftech.com/unreal-engine-5-deep-dive-million-hig-poly-objects-60fps-ps5/

I guess it's not really relevant how little or how much it uses. Ultimately, it's about ensuring that whatever Sony gives to developers, that the expansion should by and large provide the same or better spec than what PS5 offers. That's the whole reason why backwards compatibility is so challenging. Its why, XSS regardless if it has the compute or bandwidth to run X1X titles, missing those 2 GB of ram is the whole reason it can't without some sort of recompile.

There has to be standard that these drives much reach in every scenario: read/write sequential, read/write random, different block sizes, how it performs under different temperature scenarios etc.

All of those need to meet spec, not just the maximum theoretical throughput.

Now Cerny says drive will need to be operating at 7GB/s to match the number of queues the PS5 has at 5.5GB/s. At least this is what I recall. But if you're dipping below 7GB/s because of thermal throttling, you're no longer really at spec right. So it's gotta be able to hold 7GB/s throttled for instance.
Those are the type of things that I'm looking at right now.

I'm not saying there will never be an SSD that will go in there, I'm just waiting for the final list to come out before to see the spec before I speculate more.

 

[function]

Now Cerny says drive will need to be operating at 7GB/s to match the number of queues the PS5 has at 5.5GB/s. At least this is what I recall. But if you're dipping below 7GB/s because of thermal throttling, you're no longer really at spec right. So it's gotta be able to hold 7GB/s throttled for instance.
Those are the type of things that I'm looking at right now.

I'm not saying there will never be an SSD that will go in there, I'm just waiting for the final list to come out before to see the spec before I speculate more.

I don't recall Cerny saying that the expansion drive would need to be 7GB/s, merely that it would need to be faster. I don't think he actually gave a figure. The whole 7GB thing seems to have been pulled from the ether.

As you say there's a lot more to an SSD's performance than just peak sequential read, and I suspect high peak sequential read is going to be only one of many factors.

And you raise a good point about sustained performance / throttling. There has to be some kind of baseline for performance that developers can count on, or else seamless streaming that really pushed the PS5 is going to be less than seamless. I can imagine it potential even causing stability problems for games that haven't been built around PC like variability.

 

[Jay]

I don't recall Cerny saying that the expansion drive would need to be 7GB/s, merely that it would need to be faster. I don't think he actually gave a figure. The whole 7GB thing seems to have been pulled from the ether.

Could be wrong, but pretty sure it was from Cerny.
He gave the figure to indicate just how performant the PS5s customisations are and what sort of speed you would require to match it when upgrading due to the extra priority channels it has.

Probably would need to scrub through the road to PS5 to find it, or DF write up on it.

 

[Silent_Buddha]

You mentioned this before and I forgot to come back on it. Is there a link that details this? This sounds like some early manufacturing issue that occurred once or twice and has since been resolved because ther is no technical reason for this that I can think of.

This article touches on it somewhat.

https://www.eetimes.com/the-future-of-charge-trapping-flash-memory/

Basically it comes down to a cells ability to hold a charge. The smaller the node the thinner the walls of the cell are. This leads to increased degradation with an increased likelihood of intercell interference.

This problem is compounded when you move down from SLC -> MCL -> TLC -> QLC as each of those further thins the boundary between cells holding a charge.

Prior to NAND manufacturer's moving to layered NAND chips there was some concern as to how far they would be able to scale NAND capacities due to this. This is why they backed off small node NAND and instead focus on larger nodes with increased layer counts as a way to increase capacity without reducing endurance too much. The 980 Pro is up to 128 layers now, but has also switched to TLC (for cost reasons). This allows for greater capacities at the expense of SSD endurance.

You'll note that the new 980 PRO (TLC) is rated for half the endurance of the 970 PRO (MLC), or the same as the 970 EVO (TLC). This is still enough for the vast majority of consumers so it likely isn't anything to worry about, but enthusiasts aren't happy about it. But it's the main thing that makes the 980 PRO as affordable as it is at launch.

Something else to consider when looking to put a consumer NVME into the PS5, heat will also drastically reduce the effective endurance of NAND cells.

https://cdn.selinc.com/assets/Literature/Publications/White Papers/0015_NANDflash_IO_20141211.pdf?v=20170217-161047

As 7 GB/s NVME's will be generating quite a bit of heat at those speeds, it behooves Sony to ensure that there is sufficient active cooling for user installed NVME drives.

There's going to be a bloodbath of throttling and potentially dying NVME drives in PC's once DirectStorage is ubiquitous and games designed for it are common. I'm tempted to stick with 2.5 GB/s and lower speed NVMEs when it happens rather than going to the trouble of ensuring I can keep it sufficiently cool in my case.

Regards,
SB

 

[Silent_Buddha]

Why on earth would the PS5 SSD need to run for such a length of time!? A whole game can load in a few seconds- you are using an impossible scenario to prove a point. To put it another way, how much data can be moved in 110 seconds? How many game will need to do that?

Depending on the cooling the drives get when put into the PS5, it may or may not need to read continuously for that long to throttle, or read sporadically for twice as long to throttle.

Without active cooling, it can take a LONG (minutes to 10's of minutes) time for the NAND cells to cool down significantly. Thus even sporadic reads if they happen over a period of a few minutes can get the drives to a temperature where the drive will throttle.

This is why some of us are really interested in seeing a PS5 teardown. Once we see that, then there's potentially far fewer unknowns with how Sony are doing things...or maybe there will be even more questions.

Regards,
SB

 

[Jay]

I don't recall Cerny saying that the expansion drive would need to be 7GB/s, merely that it would need to be faster. I don't think he actually gave a figure. The whole 7GB thing seems to have been pulled from the ether.

About 22min 15seconds in to road to PS5.
Your right, he mentions 7Gb/s drives hitting the market, size, cooling, form factor. So that's where the figure comes from.

But he didn't say that's what would be required. He only said its going to need a bit more speed compared to the inbuilt drive due to the priority que amounts.

Worth watching that section again.

 

[function]

Could be wrong, but pretty sure it was from Cerny.
He gave the figure to indicate just how performant the PS5s customisations are and what sort of speed you would require to match it when upgrading due to the extra priority channels it has.

Probably would need to scrub through the road to PS5 to find it, or DF write up on it.

Not in Cerny's Road to PS5 presentation I'm afraid, I've just had a scan. He does mention that drives that can saturate PCIe Gen 4 x4, hitting 7GB/s, will be available by this year's end. But he doesn't say that this will be necessary to work in PS5.

I'm interesting in seeing what the IO capabilities of the recommended drives are. Currently SSDs on PC aren't really pushed as hard as they could be, I guess we might get an early indication of which drives will perform best with Direct Storage on PC!

Edit: Haha, you beat me to it

 

[Jay]

It will be interesting just how many drives are on the list of supported drives and the specs of them.
But he only committed to that to be produced probably by the end of the year.

I guess we might get an early indication of which drives will perform best with Direct Storage on PC!

Wouldn't expect early indications via direct storage.
Doesn't sound like it's due on pc until next year?

 

[goonergaz]

I don't recall Cerny saying that the expansion drive would need to be 7GB/s, merely that it would need to be faster. I don't think he actually gave a figure. The whole 7GB thing seems to have been pulled from the ether.

As you say there's a lot more to an SSD's performance than just peak sequential read, and I suspect high peak sequential read is going to be only one of many factors.

And you raise a good point about sustained performance / throttling. There has to be some kind of baseline for performance that developers can count on, or else seamless streaming that really pushed the PS5 is going to be less than seamless. I can imagine it potential even causing stability problems for games that haven't been built around PC like variability.

But again you’re assuming a lot. You’re assuming the 5.5 figure from Sony is sustainable, not sure they (or even MS) have stated as much?

I think it’s fair to say whatever measure Sony are using they are aware of what products are coming out that will be compatible, IIRC Cerny even states that drive slow will be out around the same time as PS5.

All this assuming the worst when it comes to Sony and the PS5 is frustrating.

 

[manux]

But again you’re assuming a lot. You’re assuming the 5.5 figure from Sony is sustainable, not sure they (or even MS) have stated as much?

I think it’s fair to say whatever measure Sony are using they are aware of what products are coming out that will be compatible, IIRC Cerny even states that drive slow will be out around the same time as PS5.

All this assuming the worst when it comes to Sony and the PS5 is frustrating.

Typically consoles provide deterministic behavior. Sony went to great lengths to ensure every ps5 boosts same under every load(dynamic gpu/cpu clocks). I don't see any reason to believe sony would not have done same for ssd. It's not rocket science to run ssd at max perf. Just have good enough cooling available.

 

[Silent_Buddha]

All this assuming the worst when it comes to Sony and the PS5 is frustrating.

Versus people assuming the best?

When no details are known other than some vague words and non-committal assurances?

If you assume the worst then if it turns out better (which it should) than you'll always end up happy.

If you assume the best and it doesn't live up to that, then you may end up disappointed.

Also, you may be thinking that people are assuming the worst, when (at least for me) I'm just pointing out things that have to be dealt with if people expect a user installed drive to perform as consistently as the drive that is included with the machine. I'm not saying it is or isn't going to perform sufficiently well...after all I haven't seen how Sony plan to deal with the heat and potential throttling of user added drives.

I'm certainly far more concerned with the current state of NVME cooling in the PC space which ranges from excellent (PCIE actively cooled NVME cards) to uncooled NVME drives sitting on the motherboard sandwiched between PCIE slots with virtually no airflow.

People should rightly do the same for the XB-series external drives. But there are some key differences.

• It's rated for a conservative speed, hence cooling requirements are vastly reduced.
• We have seen what they've done to address heat buildup.
  • There's a metal shroud that acts as a heat spreader and the drive is inserted into a location with direct airflow.
  • IE - it's not in a location that may get little to no airflow like the NVME drives in many PC cases.

So, having those 2 pieces of information we can make an informed decision as to whether the drive may or may not be sufficiently cooled.

If the drive speed were higher, say 5.5 GB/s and MS claimed that as sustained speed then I would have serious doubts as to how well they could cool their expansion card with the current cooling system they have for it. But it's not, so while it's possible it could happen, it's unlikely that the XB-series external drives will overheat. Perhaps if you put it next to a high heat source like a hair dryer, it'll likely throttle.

Regards,
SB

 

[goonergaz]

Versus people assuming the best?

When no details are known other than some vague words and non-committal assurances?

If you assume the worst then if it turns out better (which it should) than you'll always end up happy.

If you assume the best and it doesn't live up to that, then you may end up disappointed.

Also, you may be thinking that people are assuming the worst, when (at least for me) I'm just pointing out things that have to be dealt with if people expect a user installed drive to perform as consistently as the drive that is included with the machine. I'm not saying it is or isn't going to perform sufficiently well...after all I haven't seen how Sony plan to deal with the heat and potential throttling of user added drives.

I'm certainly far more concerned with the current state of NVME cooling in the PC space which ranges from excellent (PCIE actively cooled NVME cards) to uncooled NVME drives sitting on the motherboard sandwiched between PCIE slots with virtually no airflow.

People should rightly do the same for the XB-series external drives. But there are some key differences.

• It's rated for a conservative speed, hence cooling requirements are vastly reduced.
• We have seen what they've done to address heat buildup.
  • There's a metal shroud that acts as a heat spreader and the drive is inserted into a location with direct airflow.
  • IE - it's not in a location that may get little to no airflow like the NVME drives in many PC cases.

So, having those 2 pieces of information we can make an informed decision as to whether the drive may or may not be sufficiently cooled.

If the drive speed were higher, say 5.5 GB/s and MS claimed that as sustained speed then I would have serious doubts as to how well they could cool their expansion card with the current cooling system they have for it. But it's not, so while it's possible it could happen, it's unlikely that the XB-series external drives will overheat. Perhaps if you put it next to a high heat source like a hair dryer, it'll likely throttle.

Regards,
SB

It’s not blind faith but let’s be honest here, 825gb with a chunk dedicated to O/S means if Sony have half-heartedly implemented the SSD expansion then it will literally blow up in their faces.

I do have faith in Sony, maybe more than I should, but that’s based off a pretty good experience with PS4 and confidence in Mark Cerny. I would think Sony could easily make a proprietary SSD and make some money, but they have chosen not to do so - maybe something learnt from the Vita memory card days.

As I keep saying, time will tell and I’m more than happy to admit when I’m wrong.

 

[Unknown Soldier]

It’s not blind faith but let’s be honest here, 825gb with a chunk dedicated to O/S

If rumours are true, the O/S is only 2GB. Not a huge chunk. Not sure if it will have virtual memory set aside but that's a difference conversation entirely.