Mark Cerny Explains How the PS4′s 8 GB GDRR5 RAM and Bus Work and Why They Were Chosen

The PS4′s loving dad (or at least one of its fathers) Mark Cerny did a lot of thinking on the console’s architecture even before the first piece of circuitry was printed, so he's the best one to explain how the much touted 8 gigabytes of unified GDRR5 RAM coupled with the bus work, and why that solution was implemented.

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PositiveEmotions4005d ago

Why doesnt n4g just makes one article telling everything that mark cerny explain instead having so many articles on mark cerny explained this and that..

No offense n4g

Prcko4005d ago (Edited 4005d ago )

mostly site editors make stories on their websites,and they submit those stories here for hot temperature
after few weeks i kinda know those websites:
dualshockers,playstationlifes tyle,dso gaming,gamechup and few others :)

cayleee4005d ago (Edited 4005d ago )

No offence but why doesnt Mark Cerny ever talk about the CPU, which happens to be a tablet CPU running at 1.6ghz or whatever it is?

Or why not mention the mobile GPU within the machine. Why focus on something like RAM which essentially does no calculations. Its just a container that holds Data and transports it. How fast that Data gets processed essentially depends on CPU & GPU funnily both of those are never talked about.

CryofSilence4005d ago (Edited 4005d ago )


The modified Jaguar AMD CPU is a desktop based, x86 8 core CPU. Tablets generally use ARM based chips. Point one: invalidated.

The GPU outperforms in specs capable desktop GPUs. Point two: invalidated.

RAM is the highway on which calculations are transferred. Increase the number of lanes and the speed limit, and you get better results. The processors will have no problems filling that; most current processors wouldn't have problems either. Point three: invalidated.

Stop trolling and read a little.

loulou4005d ago (Edited 4005d ago )

caylee becareful. you cannot say things like that on n4g.

have a look at crysis 3 or bf3/4 recommended ultra settings, and you will see that the amount of RAM is not huge at all.

it is the cpu and gpu that make the difference.

but dont bother trying to say that on here. they dont want to hear things like this. all of a sudden ram is the new buzzword, just like cell was back in the day.

and yes kids i have a ps4 on pre-order

arjman4005d ago

Stop turning it into a fanboy-related comment, cayleee stated that the CPU is a tablet processor when in reality the 8-core X86 processor will outperform any ARM processor on the market.

Cayleee if you're gonna troll at least do it properly. If you were an XBox fan you'd know the CPUs in both consoles are very similar and if you were a PC fan you'd know that the 8-core APU isn't comparable to a mobile part. So I ask, what the hell is your deal?

awi59514004d ago (Edited 4004d ago )


In reality all amd 8 core cpus suck major (&*)&*. Except maybe the 8350 and 8320 and these cpu's in these consoles arent those so its a huge fail on both microsoft and sony's consoles. Console guys should really stop talking like they know anything about pc parts.

I dont think the parts in these consoles are even worth 400 and 500 dollars i think they both are pulling a apple and trying to make major profit off the consoles day one. Because both these consoles sound like gaming Laptops. My Pc far outperforms every card in the 7000 series of amd cards except a 7990 which is a 800 dollar card and these cards dont come close.

So ill just stick to my pc and still have better looking games. I get 110 fps in BF3 on ultra at 1080P right now. Ill put my Pc performance on BF4 against both these consoles and i bet ill still come ontop with fPS performance and graphcis.

starchild4004d ago


Actually the AMD CPU in the PS4 and Xbox One utilizes their Jaguar core, which also powers their Kaveri APU, which IS in fact designed for use in tablets and netbooks.

Jaguar has about one quarter the performance per core as an i5 2500k.

arjman4004d ago (Edited 4004d ago )

Its hard to gauge the true performance of a CPU & GPU combo without truly optimising a game for the hardware. Yes the comparable AMD parts will lose in PC game benchmarks and general benchmarks compared to high end parts but that's because the consoles need low power, low heat components.

With proper optimisation we'll see just how capable these consoles are. I too game on PC and I can appreciate the heat and power specs they have to meet. There's no point comparing the consoles to an i5 and titan equipped PC which most likely has several fans cooling it while it sucks up several hundred watts because they can't get that kind of power in a console sized case.

And I don't appreciate the way you talked up your own PC bragging about it and such, all you're doing is giving PC gamers a bad name.

@star child
The key word is 'utilizes', Nvidia utilize their desktop architecture in their mobile parts for example.

awi59514004d ago


Don't patronize me man the PS fanboys have gone completely mental lately talking about how the PS4 is so much better than the average pc's we game on. Go talk to them about how they are acting. Im just setting the record straight the specs they tout so much pc cards had those specs 3 years ago well actually they were higher.

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Abriael4005d ago (Edited 4005d ago )

Because it would be an enormous wall of text that would bore most people after the first two pages, while it's a lot easier on the eyes and on the brain to read on specific topics, that are of interest and relevant on their own.

TechnicianTed4005d ago (Edited 4005d ago )

No Abriael, it's so sites can make more than one article based on one interview. Let's not make it out to be more than it is.

This is what I hate about so called journalism from many of the two bit sites we now get flooded with.

No real journalism, just picking through the bones and getting hits based on headlines.

Abriael4005d ago (Edited 4005d ago )

@TechnicianTed: if you're not interested, you're entirely free not to read it.

This kind of thing is relevant, whether you like it or not, so I'm not exactly sure why we should omit it to make you happy.

There's very little "bone picking" here, considering that it's the first time the founding architecture of the console has been really explained in detail.

Maybe you should just bring your rage elsewhere?

besides, you don't even know what we're talking about, since this isn't an interview, but a 50 minute conference, so maybe you should get your facts straight?

And it's a very intense conference with a ton of relevant info.
Good luck putting that all in a single article without boring the hell out of your readers.

TechnicianTed4005d ago

'@TechnicianTed: if you're not interested, you're entirely free not to read it. '

I didn't.

'This kind of thing is relevant, whether you like it or not, so I'm not exactly sure why we should omit it to make you happy. '

It's been covered already, it's old news.

'There's very little "bone picking" here, considering that it's the first time the founding architecture of the console has been really explained in detail. '

Explained by the man himself, in the full conference, in better detail than the article.

'Maybe you should just bring your rage elsewhere? '

I haven't got any rage, maybe you have because I insulted your website?

'besides, you don't even know what we're talking about, since this isn't an interview, but a 50 minute conference, so maybe you should get your facts straight?'

I was talking in general. Many websites, including your own, pick through an interview, or in this case a speech given by a developer, and make an article based on a certain passage in that interview, or speech, and make an article on it. Are you denying that is not what this article is?

This very article is based on a small amount of what the full speech amounted to. I'm sorry but we already know, it's not news. It's picking out of the bones and making out that you did all the work.

You did nothing, there's no journalism here. No one on your site has made any real effort with this article. This is something that anyone on the internet could do, it involves no skill whatsoever.

'Good luck putting that all in a single article without boring the hell out of your readers. '

Maybe if your staff had some talent it wouldn't be an issue. If your site actually provided some real journalism I wouldn't be saying what I'm saying.

But your site is one of those two bit sites, so I suppose the truth hurts.

mrmarx4005d ago

more clicks.. more money

fr0sty4005d ago (Edited 4005d ago )


You didn't even read the article, which proves you are just talking out of your ass. If you were a real journalist, you would know that keeping your readers engaged and interested is a very big part of it. Presenting them with a 5 page wall of text is not going to keep them reading, and many important details will get lost in the mix. By breaking the story down into individual elements, it allows the journalist to elaborate in much more detail about what was said instead of just a passive mention about it. It allows for deep technical analysis, rather than just bullet point mentions. That's how you properly cover a story without turning it into a novel.

It took 50 minutes just for Cerny to say these things. As a journalist, I wouldn't just cover what he said alone. I would know that my readers may not even understand what the hell he is talking about, so I would do my best to break the technical babble down into layman's terms so everyone could have a grasp on what was being said. I would explain in detail how every bit of what he was talking about worked. By doing so, it would take what took someone 50 minutes to say and turn it into what would take 5 hours to read. Not good for an internet article, so therefore it would have to be broken up.

nix4005d ago

should have just posted the 45 minute long video and the highlights.

+ Show (4) more repliesLast reply 4005d ago
mushroomwig4005d ago

How else are they supposed to milk those hits?

mrmarx4005d ago

lol you almost said "tits"

a_squirrel4005d ago

They are the tits of the industry, and they have been swelling with milk since E3.

adorie4005d ago

All aboard the 256 bit bus.

starchild4005d ago

I think Sony were very smart in their designing of the PS4. The x86 ISA and the overall familiar PC-like architecture is going to be great for ease of development.

It's interesting to me to compare to my HD 7950 graphics card in my PC which is based on the same AMD GCN architecture.

The Xbox One has 12 compute units, the PS4 has 18, and my HD 7950 has 28. And instead of a 256 bit bus, the HD 7950 has a 384 bit bus.

4005d ago
fr0sty4005d ago

I would expect similar performance out of PS4 than what you get out of your GPU. Mainly due to not having OS overhead (PS4's OS runs on a small chunk of RAM and even has it's own ARM sub-CPU so the main system CPU doesn't have to process any OS commands at all), the developers are able to have much finer control over the hardware rather than having to work with restrictive APUs, and your PC GPU lacks a few advantages such as being able to issue 64 compute commands at once or having a direct bus connecting the CPU to the GPU. Your CPU and GPU are connected with one PCI express bus, so there is a bandwidth advantage on PS4 due to both chips being on the same die. Also, due to having one pool of RAM, if the GPU wants to help the CPU (or vice versa), they don't have to wait the amount of time it takes to copy that data into their local pool of RAM before they can begin working on it.

This can be made up for somewhat due to the fact that you have more raw power in your CPU and GPU, but your system is only as fast as it's slowest component. PS4 is a finely tuned gaming machine. More so than any PC is for the reasons listed above (and more, I didn't even list all of the customizations made to PS4's GPU).

So, once you balance all that out, you'll very likely end up with similar performance out of the two. You may get a slightly higher framerate out of the PC in certain titles, but I wouldn't expect much more.

Valkyre4005d ago

@ WeMilk

your buses are not enough to display grand theft auto V upon release, they were never interesting enough for red dead redemtpion, the Last of Us dont like your buses either, Metal Gear Solid V "might" at some point enjoy your buses etc etc etc

I believe you get the point...

Enjoy your buses and your limited library of games. Maybe one day you will realise tht your PC has nothing exclusive to it and all those years your buses are essentially inactive because all you do is play console ports with a few texture and resolution upgrades.

But hey,.. good times!

Now that new generation consoles are out, perhaps your buses will actually start working... but i dont want to burst your bubbles... you probably are going to need to upgrade your hardware... :(

AndrewLB4005d ago

People don't seem to realize that memory bandwidth is not some kind of game changer considering the PS4's GPU will never come close to utilizing it all. A great example was inadvertently made by starchild with his HD 7950. That card with it's 384-bit memory bus has a bandwidth of 240gb/s, a texture fillrate of 89.6GTexels/s, and pixel fillrate of 25.6GPixels/s. In contrast, the GTX 680 which by all accounts completely destroys the 7950 has only a 256-bit bus and bandwidth of 192gb/s, while having a texture fillrate of 144.8GTexels/s and pixel fillrate of 36.2GPixels/s.
This proves that memory bandwidth is only useful if the GPU is powerful enough to use it, and much of the HD 7950's massive bandwidth is never utilized, and goes to waste.

Btw... the graphics card that is much closer in performance to the PS4 would be the HD7850. The memory bandwidth and 1.7TFlops are very close to the PS4.

Frosty- Again you equate higher free memory bandwidth with actual performance, but that doesn't change the fact that his card can process 2.9Tflops while the PS4 is at 1.7Tflops, not counting the fact that the HD 7950 has almost DOUBLE the PS4's texture fill rate. Additionally, the OS overhead PC's have to deal with because of windows almost completely falls on the CPU, and not the GPU. When a full screen game is run, GPU's switch to a kind of exclusivity mode which allows the GPU to have almost complete focus on the game itself, but it's the CPU that has to not only run the game, but everything windows related in the background.