PlayStation 4 OS consumes 3.5GB of RAM

[GoodBytes]

The guys over at Digital Foundry and ArsTechnica found that the PlayStation 4 OS consumes 3.5GB of the 8GB GDDR5 of the PlayStation, leaving only 4.5GB for the game, and GPU memory. This is compared to the PS3 where it's OS only consumed 96MB of it's 512MB. And the XBox One had as a limit of staying at or under the 3GB mark, which is what it consumes based on reports.

 

Source: http://arstechnica.com/gaming/2013/07/report-os-overhead-takes-up-3-5gb-of-ps4s-8gb-of-ram/

 

It is interesting to see what is so special in the PS4 to make it consume so much RAM. In comparison, Windows 8 only need 1GB to operate full featured.

 

 

What do you think about all this? Also, what do you think about what the PS4 will be doing on the back to consume so much memory?

[Vitalius]

What do you think about all this? Also, what do you think about what the PS4 will be doing on the back to consume so much memory?

I'm pretty sure I can accurately answer that question based on what I know. 

The PS4 has a secondary CPU dedicated to updating, streaming, and doing video encoding that runs simultaneously with the gaming side of things. Meaning you can play a video game while streaming it (like has been advertised) as well as download updates to your system.

The streaming/video encoding thing is what I'm going to guess pushes the OS to such large RAM usage.

Edit: I imagine, if they actually use the resources efficiently, if you aren't streaming/downloading updates, your game will have full access to all the VRAM, but I doubt it will change on the fly for this. 

If I had the option of disabling those features (particularly video streaming) entirely for more draw distance in games, that'd be lovely.

[CoolBeans]

That is ridiculous Windows 7 only uses 250MB and that can actually do something useful.

[WorldDominator]

The guys over at Digital Foundry and ArsTechnica found that the PlayStation 4 OS consumes 3.5GB of the 8GB GDDR5 of the PlayStation, leaving only 4.5GB for the game, and GPU memory. This is compared to the PS3 where it's OS only consumed 96MB of it's 512MB. And the XBox One had as a limit of staying at or under the 3GB mark, which is what it consumes based on reports.

 

Source: http://arstechnica.com/gaming/2013/07/report-os-overhead-takes-up-3-5gb-of-ps4s-8gb-of-ram/

 

It is interesting to see what is so special in the PS4 to make it consume so much RAM. In comparison, Windows 8 only need 1GB to function.

 

 

What do you think about all this? Also, what do you think about what the PS4 will be doing on the back to consume so much memory?

Either they're up to something sneaky or someone doesn't know what they're doing. I'd prefer to hear the latter since I'm probably going to get an xbox one :D

[kuddlesworth9419]

That is crazy, sounds like Sony did something really wrong there. The OS will be no Windows so why does it consume so much RAM. When I close my browser with nothing on W7 consumes 1.78GB of RAM but with a clean install it consumes about 250MB of RAM.

[rustikles]

It better have a crazy beautiful UI for that much RAM being taken up.

[mvitkun]

That is crazy, sounds like Sony did something really wrong there. The OS will be no Windows so why does it consume so much RAM. When I close my browser with nothing on W7 consumes 1.78GB of RAM but with a clean install it consumes about 250MB of RAM.

a clean install for me still has it taking around .96gb

[3DOSH]

I don't think that's a lot, it may be that windows 7 needs about 1.5 GB but that's including a page file and when you put that out of the equation 3.5 Gb for OS alone sounds about right.

[TopWargamer]

But Sony said it only consumes 1GB of RAM...heh...those liars. 

[samuel]

My OS uses like 6Gb of memory from 14 Gb total when doing basicaly nothing. Why you may ask? Because it's there and the OS makes good use of it (caches and such)! When a program (game) needs lot of RAM, the OS will make sure that program will have enough memory, leaving down to ~500MB for desktop usage! I actually hope that future versions of Windows will use like 50% of 32GB for caching, minimising the HDD/SSD bottleneck.

[Vitalius]

From the article:

 

In Sony's case, at least, there's some hope that this allocation could change in the future, with "sources close to Sony" suggesting the OS could take up less RAM with future streamlining updates.

In the comment below it:
 

 

This isnt really relevant without knowing exactly what role the OS plays in running a game, thing have changed since days of gaming past. Previously when running a game, the game was the only thing running, there wasnt really an OS to speak of beyond something really basic so the game had full access to everything.
 

Now adays that isnt really the case as the OS's on these new machines are always running in the background. Now where that comes in to play is how much interaction the games have with the OS while they are running.

Working with an embedded system (stb) that deals with HD video all day, I can tell you we have 2GB of ram, but at least half of that is reserved for the system drivers in kernel space (which could be considered having half of the memory reserved by the OS). This is because they have all the buffers needed to handle the HD video as well as shuffling other things around through DMA transactions and such.

So if these new consoles are making OS calls to handle more video, or the OS is the one that owns the video buffers, then having that much ram reserved by the OS makes complete sense and doesnt actually hinder the games at all

 

I agree with him.

[Cypher32]

Guys its not about how much windows 7 needs minimum etc. its the fact that Sony need to be a future proof number set in stone so that they have room to grow and it along with when  background processes are running the OS never goes over 3.5gb. This way developers know how much ram is available for sure. Also the article says there is 1 gb of flex ram and these numbers might change.

[ionbasa]

Well, There are some things that aren't explained in the article:

1. The OS could have been doing something in the background, like downloading an update.
2. The PS4's OS is supposedly "linux like" .
3. There are two chips in the PS4.

So let me put it this was The AMD APU ( 8 core CPU + GPU) is the main chip which which has available 8 Gb of GDDR5 Memory.

But, there is also a secondary "dual core" processor on the system which also handles background tasks and the presumably the OS. Now the CPU and APU should  (not necessarily) have 2 different memory banks.

 

AKA one CPU can't access another CPUs memory on its own data bus (unless there is some UMA (Unified Memory Access) implemented(which I doubt.))

 

Conclusion:

So theoretically the OS memory should be separate from the 8Gb GDDR5. If that is the case then why are people freaking out over how much memory the OS requests? Plus when you will play a game on the PS4 the OS should hopefully "go to sleep" per say because of a hardware "Hypervisior" ( the same thing happens on the PS3, so it is safe to assume the same for the PS4.)

[Cypher32]

@ionbasa They are using the 8gb of the GDDR5 i bieleve you are mistaken in that 2 cores of the 8 core processor is used for the OS if i'm not mistaken

[ionbasa]

@ionbasa They are using the 8gb of the GDDR5 i bieleve you are mistaken in that 2 cores of the 8 core processor is used for the OS if i'm not mistaken

http://www.gamasutra.com/view/feature/191007/inside_the_playstation_4_with_mark_.php?page=3

There's also another custom chip to put the system in a low-power mode for background downloads. "To make it a more green hardware, which is very important for us, we have the ability to turn off the main power in the system and just have power to that secondary custom chip, system memory, and I/O -- hard drive, Ethernet. So that allows background downloads to happen in a very low power scenario. We also have the ability to shut off everything except power to the RAMs, which is how we leave your game session suspended."

There is a secondary dual core chip! @2:26

http://www.youtube.com/watch?v=HF4F0TvCDcQ&feature=youtu.be&t=2m26s

[GoodBytes]

I don't think that's a lot, it may be that windows 7 needs about 1.5 GB but that's including a page file and when you put that out of the equation 3.5 Gb for OS alone sounds about right.

Pagefile is on the HDD/SSD not in memory.

The reason why we have the pagefile, is not for 1 program/game to get enough memory, but rather because it's impossible to know how many programs you have running, and if you want to have 3D Studio Max, PhotoShop and 2 games running, which the user alt+tab between on 4GB, the system or less, you can no problem. It will be slow when switching, but you can.

 

Here this is a gaming console. It runs 1x OS (including all it's components), and 1x game. It knows for sure that you won't be running 2 games at the same time, as you can't. And devs knows how much space they can work with, and live with. Also it must be noted that 1 program cannot use the pagefile AND RAM at the same time. A program memory block can't be split. It always stays in 1 block.

 

My OS uses like 6Gb of memory from 14 Gb total when doing basicaly nothing. Why you may ask? Because it's there and the OS makes good use of it (caches and such)! When a program (game) needs lot of RAM, the OS will make sure that program will have enough memory, leaving down to ~500MB for desktop usage! I actually hope that future versions of Windows will use like 50% of 32GB for caching, minimising the HDD/SSD bottleneck.

Yes it's SuperFetch in action. The PlayStation doesn't need such technology. It won't pre-load your games before you do, or something. All I can think about is that when you start the PS4, it loads EVERY single applications inside, running all the time for fast load. While this is a possibility, it's a stupid one. Imagine if Windows did this.

 

Guys its not about how much windows 7 needs minimum etc. its the fact that Sony need to be a future proof number set in stone so that they have room to grow and it along with when  background processes are running the OS never goes over 3.5gb. This way developers know how much ram is available for sure. Also the article says there is 1 gb of flex ram and these numbers might change.

That is why Microsoft sets as minimum specs 1GB for Windows 7 and 8.

You can run Windows 7 and 8, on a system with less memory. And needs to go a step further, because you have an integrated graphic card using shared memory.

And there is a plenty of possible configuration Microsoft needs to take into account, including but not limited to a system with an active integrated graphic solution, and a dedicate graphic card using system shared memory. Of course, to some extent. I guess 128MB each, so 256MB headroom. But I am just guessing, I have not tried it. But for sure Windows 7 and 8 runs fine on system with less than 1GB available.

 

Well, There are some things that aren't explained in the article:

1. The OS could have been doing something in the background, like downloading an update.

How much RAM did you need back in WIndows 98 days, to download stuff? Microsoft states 24 MB recommended, 16MB minimum.

Let's say, you have 32MB, because you had a 4000$ gaming PC at the time. 32MB running Windows 98, and you could download anything you wanted.

It doesn't make any sense that the second processor, assuming has it's own OS, consumes more than 64MB of RAM, let alone 32MB, just to download stuff. It has no graphical user interface to render, it doesn't have a bunch of drivers to load in memory. All it does is access the Sony servers to download updates.

[ionbasa]

How much RAM did you need back in WIndows 98 days, to download stuff? Microsoft states 24 MB recommended, 16MB minimum.

Let's say, you have 32MB, because you had a 4000$ gaming PC at the time. 32MB running Windows 98, and you could download anything you wanted.

It doesn't make any sense that the second processor, assuming has it's own OS, consumes more than 64MB of RAM, let alone 32MB, just to download stuff. It has no graphical user interface to render, it doesn't have a bunch of drivers to load in memory. All it does is access the Sony servers to download updates.

I would agree with you, but the console isn't running Windows 98. Didn't Bill also say that 640Kb of RAM is all that someone will ever need?

 

I will rebuttal you argument about not needing more that 64Mb of RAM for downloading a game off the Internet. 

 

First there is only 1 Hdd in the system. So the extra ram usage could have been because the content was cached to ram before being written to the HDD. This could be especially true it the main processor was also accessing the HDD for say loading textures. Once the main processor was done read/writing to the HDD then the content stored on the RAM could be dumped to the HDD.

[Cypher32]

@ionbasa I stand corrected

[Kajornkeat]

Well, if it consumes that much RAM, could it be a RAMDisk? Put whole OS+apps into RAMDisk for better performance and left other stuff on HDD? 

[samuel]

Well, if it consumes that much RAM, could it be a RAMDisk? Put whole OS+apps into RAMDisk for better performance and left other stuff on HDD? 

PS4 is a gaming "PC" so a GDDR5 ramdisk (of any size) is a very bad idea! This memory is fast and expensive, designed especially for bandwich hungry GPUs.  

[BurpleMan]

Pretty sure this can be taken with a pinch of salt, no context for the numbers is even provided. 

[GoodBytes]

From Sony internal doc:

http://www.eurogamer.net/articles/digitalfoundry-ps3-system-software-memory

Sony's internal docs say that 4.5GB is the baseline amount of guaranteed memory available for game-makers

[beebskadoo]

I'm pretty sure I can accurately answer that question based on what I know. 

The PS4 has a secondary CPU dedicated to updating, streaming, and doing video encoding that runs simultaneously with the gaming side of things. Meaning you can play a video game while streaming it (like has been advertised) as well as download updates to your system.

The streaming/video encoding thing is what I'm going to guess pushes the OS to such large RAM usage.

Edit: I imagine, if they actually use the resources efficiently, if you aren't streaming/downloading updates, your game will have full access to all the VRAM, but I doubt it will change on the fly for this. 

If I had the option of disabling those features (particularly video streaming) entirely for more draw distance in games, that'd be lovely.

To my understanding, the game devs are only given access to 6 of the 8 'cores' while the 2 cores are used for the OS and such. Same with the memory, the devs only have a certain amount they can play with and the rest is saved for the OS. I don't think the OS needs 3.5 GB of ram to operate but it's just sectioned off so devs can't use it. 

[Nertballs]

would i be right in saying however that this is more of a 'threshold ram usage' of some sort? eg this is how much it can use so don't make games to use up more? also, the OS won't be massively loaded while you're in game, so maybe they might dynamically share it while you're in game, or while you're streaming/not streaming. Well hopefully they'll do that anyway :P 

 

Post note: Why do i even care what they do, PC FTW! :D

[EChondo]

Maybe 1GB is idle, and 4.5GB is boost clock