RAM thread of Next Generation

Feb 25, 2008
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#1
Next Generation is fast approaching and the tape has been written-

-Sony: 8 GB of RAM at a 176 GB/S transfer rate in a UMA. We will assume it is GDDR5.

-Microsoft: 8 GB of DDR3 at 68 GB/S and 32 MB ED RAM running at 102 GB/S.

Developers since the dawn of time have asserted RAM is the number one bottle neck when designing games. This thread is designed for us to learn, speculate, and discuss how third party/first party games will be effected by these design decisions.

Some topics to ask ourselves-

How much OS overhead will we see? Microsoft is using 3 GB, while Sony is still in a flux.
Which configuration offers the best flexibility? I would venture PS4 since it is the least fussy.
How can engines benefit from each situation?
What are the advantages of a larger and faster RAM pool?
 
Feb 25, 2008
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#3
Possible that Sony may add extra ram for the OS like the Wii?
My post in another thread:

I have a theory on how Sony could use 4 GB of GDDR5 with an OS overhead.
I am quite certain the PS4 has 4 GB of UMA RAM at 192 GB/S, no more, no less.

The PlayStation 4 OS will take up around 1 GB of of memory when it is booted up. However, when you are gaming, the OS shrinks down considerably to 256 MB of RAM and ONLY allows notifications and one app to "fully" run concurrently (IE Facebook notifications, Skype Calls, etc.). GDDR5 is fast enough so when you hit the "PS" button, your game pauses in the background and the OS reinflates to 1 GB once again. Allowing you the full suite of function while the game is paused in the background.

This technique is currently being used in the Vita. When you game the OS shrinks down considerably and runs a 'lite' version of itself in the background. These numbers are abritrary and pulled out of my ass. I think an economical and common sense approach where Sony allows developers 3.75 GB of GDDR5 to use in gameOS is more than generous, and a financially sound decision as opposed to chucking in another 2 GB DDR/LPDDR RAM module. The cost savings over times will be huge.
 

gofreak

GAF's Bob Woodward
Jun 8, 2004
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#5
I think in looking at RAM, there's 4 related trends to consider.

a) How much will static data grow this gen to next? (i.e. assets spooled off discs - we can look at discs, disc size, likely avg game disc footprint this gen vs next gen, resolution growth). What was the ratio of static data on disc to static data in memory at anyone time last gen and to what extent will this grow next-gen?

b) How much will dynamic data grow this gen to next (i.e. data generated by the cpu or gpu...a function of memory bandwidth as an upper limit?)

c) How much will buses from non-volatile memory to RAM grow this gen to next?

d) Less directly relevant, but how much has PC RAM capacity grown in this transition vs previous?


In terms of flexibility, at a glance each scenario could be more flexible in different ways, possibly at different ends of the render pipeline. For example a larger pool of RAM would give developers fewer memory optimisation headaches and allow for aggressive prefetching of assets passing into the top of the pipeline. However if your render pipeline is outputting to a smaller pool of memory you have less flexibility (or more hoops to jump through) if you want to go beyond what the hardware designer envisaged wrt, say, buffer sizes and how many buffers you use to put together a frame. With one larger pool of still fast memory you wouldn't have to worry so much about juggling the pipeline's output.

I don't think there's any black and white answers to 2) in that regard.
 

gofreak

GAF's Bob Woodward
Jun 8, 2004
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#9
I'm an idiot with this stuff, but more bandwidth is better than more RAM, right?

So if those both turn out to be true, 4GB at 192 GB/s will be preferable to 8GB at 64 GB/s?
More bandwidth might be better as long as you're past the point of having 'enough' RAM.

So the answer to 2) depends on whether 4GB is enough or not.
 
Feb 25, 2008
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#10
I'm an idiot with this stuff, but more bandwidth is better than more RAM, right?

So if those both turn out to be true, 4GB at 192 GB/s will be preferable to 8GB at 64 GB/s?
Like gofreak mentioned- it's not black and white. I am hoping this thread can shed into light, in laymans terms, how each configuration will benefit us as the consumer.
 
Dec 3, 2006
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#11
From the durango thread:
http://www.neogaf.com/forum/showthread.php?t=507325&page=47

it seems to be out there, the rumor is one of the "custom blocks" is a blitter. (Another being audio DSP).

I dont even really know what a blitter is. Seems to be something from the past, but I guess it's now in next gen form.
In a computer system, a blitter is a circuit, sometimes as a coprocessor or a logic block on a microprocessor, that is dedicated to the rapid movement and modification of data within that computer's memory. A blitter is capable of copying large quantities of data from one memory area to another relatively quickly, and in parallel with the CPU, whilst freeing up the CPU's more complex ISA for more general operations.
 
#12
I'd personally go with the larger memory capacity, especially at ~70GB/s. That plus 64MB edram (which should handle 1080p frame buffers with AA or without + used for very fast access memory.

The main reason is open world games, if you want open world games, having more memory allows for this to happen, and you are still looking at 3X+ the speed of 360's memory with XB3's rumored RAM. That should handle 1080p fairly easily.

What you can do with GDDR5 is more AF and you can push the entire frame buffer to ram without seeing a hiccup compared to using the edram from microsoft. That would allow for more AA but the games would be relatively more "tunnel" like, still should be better than this generation in that regard, but XB3 could have a fairly even performance between "tunnel" designed games and open world games, though this is of course if they are limiting their tunnel games to PS4's smaller ram footprint. You'd probably see higher resolution textures on XB3 vs PS4, but PS4 would have better IQ so it could end up essentially being a wash.

As for OS, I would expect XB3 to use up to 2GB for their OS, they might shrink it overtime, but at launch, saving that much space even if they don't use it, would allow them to add features later.
 

mrklaw

MrArseFace
Jun 10, 2004
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Windsor, UK
#14
I'm an idiot with this stuff, but more bandwidth is better than more RAM, right?

So if those both turn out to be true, 4GB at 192 GB/s will be preferable to 8GB at 64 GB/s?

just to make it less straightforward - its rumoured that MS will go with EDRAM to speed things up.

So it'd be slower DDR3 (but lots of it) and EDRAM

vs

faster GDDR5 (but not so much of it)
 
Mar 2, 2007
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#15
RAM was bottleneck in the 90s and also in the last two gens. It won't be much of a concern in next gen though.

Same thing with PCs: back in the 90s, adding more RAM was the first thing to do to make the PC useful (again). Nowadays RAM doesn't seem to be topic anymore when making a new build.
 
#16
My post in another thread:

I have a theory on how Sony could use 4 GB of GDDR5 with an OS overhead.
I am quite certain the PS4 has 4 GB of UMA RAM at 192 GB/S, no more, no less.

The PlayStation 4 OS will take up around 1 GB of of memory when it is booted up. However, when you are gaming, the OS shrinks down considerably to 256 MB of RAM and ONLY allows notifications and one app to "fully" run concurrently (IE Facebook notifications, Skype Calls, etc.). GDDR5 is fast enough so when you hit the "PS" button, your game pauses in the background and the OS reinflates to 1 GB once again. Allowing you the full suite of function while the game is paused in the background.

This technique is currently being used in the Vita. When you game the OS shrinks down considerably and runs a 'lite' version of itself in the background. These numbers are abritrary and pulled out of my ass. I think an economical and common sense approach where Sony allows developers 3.75 GB of GDDR5 to use in gameOS is more than generous, and a financially sound decision as opposed to chucking in another 2 GB DDR/LPDDR RAM module. The cost savings over times will be huge.
It's a good theory. Though it would be nice if it just had a dedicated amount of ram, even if it was just an extra 512mb of GDDR5.
 
Oct 31, 2006
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#17
RAM was bottleneck in the 90s and also in the last two gens. It won't be much of a concern in next gen though.

Same thing with PCs: back in the 90s, adding more RAM was the first thing to do to make the PC useful (again). Nowadays RAM doesn't seem to be topic anymore when making a new build.
Vram is still very important, but ordinary ram isnt.
 
Oct 2, 2010
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Poland
#18
I'd personally go with the larger memory capacity, especially at ~70GB/s. That plus 64MB edram (which should handle 1080p frame buffers with AA or without + used for very fast access memory.

The main reason is open world games, if you want open world games, having more memory allows for this to happen, and you are still looking at 3X+ the speed of 360's memory with XB3's rumored RAM. That should handle 1080p fairly easily.

What you can do with GDDR5 is more AF and you can push the entire frame buffer to ram without seeing a hiccup compared to using the edram from microsoft. That would allow for more AA but the games would be relatively more "tunnel" like, still should be better than this generation in that regard, but XB3 could have a fairly even performance between "tunnel" designed games and open world games, though this is of course if they are limiting their tunnel games to PS4's smaller ram footprint. You'd probably see higher resolution textures on XB3 vs PS4, but PS4 would have better IQ so it could end up essentially being a wash.

As for OS, I would expect XB3 to use up to 2GB for their OS, they might shrink it overtime, but at launch, saving that much space even if they don't use it, would allow them to add features later.
More RAM does not mean more open world games or better open world games. If anything good streaming engine needs faster RAM and fast HDD/SSD rather than more ram since it constantly load things. And then there is LOD which uses a lot of RAM. The more RAM you have the more things you will see in distance (considering you have fast RAM and good GPU+CPU combo to hold increased amount things to do).

Skyrim is rather bad example since it goes back to morrowind where normal loading between areas were common. Cells are essentially levels which are loaded one by one and that didn't change much in Skyrim or Oblivion. True streaming engine like Witcher 2 or Uncharted loads only things that players see without loadings.

There is a reason why top GPU always have fastest ram. When you will have next gen games with improved texture sizes, polycount etc then fast ram will be essential to provide good GFX.
 
Oct 1, 2006
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peter.metaclassofnil.com
#19
I think it's exceedingly unlikely that SOny would use separate "OS Ram". The whole point of an UMA is to make both the software and hardware simpler (even if the HW is slightly more expensive to build initially, it will be cheaper in the long run).

Anyway, 192 GB/s is some nice bandwidth. For comparison, a GTX680 has ... 192 GB/s. Ba-dum-tish.
 

mrklaw

MrArseFace
Jun 10, 2004
59,901
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Windsor, UK
#20
I think it's exceedingly unlikely that SOny would use separate "OS Ram". The whole point of an UMA is to make both the software and hardware simpler (even if the HW is slightly more expensive to build initially, it will be cheaper in the long run).

Anyway, 192 GB/s is some nice bandwidth. For comparison, a GTX680 has ... 192 GB/s. Ba-dum-tish.
edram at 200+GB/s with 34 or 68GB/s main memory - how does that come out in the wash? What percentage of a rendering pipeline could run direct from edram if you have 64MB EDRAM? How about if you had 128MB?
 
Oct 1, 2006
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peter.metaclassofnil.com
#21
edram at 200+GB/s with 34 or 68GB/s main memory - how does that come out in the wash? What percentage of a rendering pipeline could run direct from edram if you have 64MB EDRAM? How about if you had 128MB?
It really depends on what you're doing in your game. If you have tons of alpha blending with low-res (particle) textures, you might do the vast majority of your memory accesses in eDRAM. On the other hand, if you're texturing every rendered pixel with anisotropic sampling from 4 high-res textures then that eDRAM doesn't help you nearly as much.
 
Feb 25, 2008
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#22
It really depends on what you're doing in your game. If you have tons of alpha blending with low-res (particle) textures, you might do the vast majority of your memory accesses in eDRAM. On the other hand, if you're texturing every rendered pixel with anisotropic sampling from 4 high-res textures then that eDRAM doesn't help you nearly as much.
In your opinion how does this translate to what you will see in game. Take any game- GTA, Battlefield, Gran Turismo, Gears of War / Uncharted, and God of War- and can you briefly highlight how each system can benefit said titles.
 
Dec 7, 2008
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London
#23
More RAM does not mean more open world games or better open world games. If anything good streaming engine needs faster RAM and fast HDD/SSD rather than more ram since it constantly load things. And then there is LOD which uses a lot of RAM. The more RAM you have the more things you will see in distance (considering you have fast RAM and good GPU+CPU combo to hold increased amount things to do).

Skyrim is rather bad example since it goes back to morrowind where normal loading between areas were common. Cells are essentially levels which are loaded one by one and that didn't change much in Skyrim or Oblivion. True streaming engine like Witcher 2 or Uncharted loads only things that players see without loadings.

There is a reason why top GPU always have fastest ram. When you will have next gen games with improved texture sizes, polycount etc then fast ram will be essential to provide good GFX.
With Skyrim on PS3, what is the connection with the player making lots of item interactions and the game eventually suffering in performance? I get that world streaming is one aspect of open world games that favours fast RAM, but isn't the PS3 Skyrim issue a different aspect that requires more RAM to be constantly available?

I'm actually asking, I have no idea.
 
Jan 3, 2013
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#24
8gb for OS and 8gb for games. Both XDR2 That's the only way you can get a huge generational leap. Do it sony.

4GB is just a waste of time. You want a console to last 10 years and only include 4? Within 2 years you will hit bottlenecks AGAIN!!
 
Feb 25, 2008
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#25
4GB is just a waste of time. You want a console to last 10 years and only include 4? Within 2 years you will hit bottlenecks AGAIN!!
Do you have any idea what you are saying? This: http://www.youtube.com/watch?v=nv4Boq4HLKU is using 1.8 GB of RAM. More RAM does not equal better. Please read the thread before coming to some silly conclusions.

The GTX 680 only has 2 GB of GDDR5, which is what Watch_Dogs, Star Wars 1313, and Agnis Philosophy is using.
 
Dec 29, 2004
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#26
RAM was bottleneck in the 90s and also in the last two gens. It won't be much of a concern in next gen though.

Same thing with PCs: back in the 90s, adding more RAM was the first thing to do to make the PC useful (again). Nowadays RAM doesn't seem to be topic anymore when making a new build.
True, I have 16GB in my current PC, and haven't seen any (recent) game use more than ~1GB of system memory. It's obviously great for multitasking and switching between those different processes though, which I expect the new consoles to do way more than the current.

Having 'just' 1GB of video memory seems to be a bigger bottleneck.
 
Dec 23, 2008
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#27
I was afraid of a thread like this where people really don't understand the key differences between GDDR5 and DDR3 and just use the simple logic of which is more and that more is better (it is if all else was equal, which it isn't).

Thuway, you should highlight and bold terms like GDDR5 and DDR3 and their ramifications in a closed system and other salient points.

Do you have any idea what you are saying? This: http://www.youtube.com/watch?v=nv4Boq4HLKU is using 1.8 GB of RAM.
True but that was just the VRAM, weren't they running it on a system with 32GB DDR3 system ram?
 
Aug 28, 2009
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#30
8gb for OS and 8gb for games. Both XDR2 That's the only way you can get a huge generational leap. Do it sony.

4GB is just a waste of time. You want a console to last 10 years and only include 4? Within 2 years you will hit bottlenecks AGAIN!!
LOL!!! someone tell about this post to that twitter account with bad post

RAM is not gonna make your games pretty. I'm not expecting more than 4GB for next gen systems.

Both of my 680 have 2GB each one
 
#31
I'm an idiot with this stuff, but more bandwidth is better than more RAM, right?

So if those both turn out to be true, 4GB at 192 GB/s will be preferable to 8GB at 64 GB/s?
Here's how I'll explain it to you (I hope I'm right. Do correct me if I'm wrong).

You've 4GB RAM for Orbis and 8GB RAM for Durango. Orbis' RAM is faster but has a lower limit. Durango's RAM is slower but has a higher limit. Each game and application has it's own demand on how much free RAM it needs at a certain time. Now imagine that a software is dumped on both consoles without any optimization at all. If that particular software requires a maximum of 4GB of RAM at a certain state, Orbis will do a far more quicker job than Durango. However, if by any chance the software requires more than 4GB of RAM at a certain time, Durango will do a better job than Orbis.

Since Durango will be Windows 8 based, it will be multitasking a lot more than Orbis will. For that reason, you need 8GB RAM, dedicate a certain amount to OS and applications, and the rest to games.
 
Aug 28, 2009
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#33
Here's how I'll explain it to you (I hope I'm right. Do correct me if I'm wrong).

You've 4GB RAM for Orbis and 8GB RAM for Durango. Orbis' RAM is faster but has a lower limit. Durango's RAM is slower but has a higher limit. Each game and application has it's own demand on how much free RAM it needs at a certain time. Now imagine that a software is dumped on both consoles without any optimization at all. If that particular software requires a maximum of 4GB of RAM at a certain state, Orbis will do a far more quicker job than Durango. However, if by any chance the software requires more than 4GB of RAM at a certain time, Durango will do a better job than Orbis.

Since Durango will be Windows 8 based, it will be multitasking a lot more than Orbis will. For that reason, you need 8GB RAM, dedicate a certain amount to OS and applications, and the rest to games.
Wow if Durango comes with some kind of gimped Windows 8 it's gonna eat a lot of RAM.
 
Oct 1, 2006
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peter.metaclassofnil.com
#34
In your opinion how does this translate to what you will see in game. Take any game- GTA, Battlefield, Gran Turismo, Gears of War / Uncharted, and God of War- and can you briefly highlight how each system can benefit said titles.
I don't feel like we know enough about the 2 systems - and I know enough about those games - to say.

I will say though that if the 192 GB/s rumour is true, it will be closer to high-end PCs in that regard than I expected, the maximum on a single-GPU card right now is 7970 with 264 GB/s. Edram is much harder to compare with off-the-shelf tech.

This is actually an improvement over PS3, which had 20.8 GB/s of GPU bandwidth while the 7800 GTX (somewhat comparable timing-wise to 7970 now) on PC had 54.4 GB/s.
 
Dec 23, 2008
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Canada
#36
They don't have to since it's the logical explanation. Think about it: Agni's philosophy was designed to consume less than 2GB. Had they been using a 4GB card, that wouldn't have been the case. The next gen development knows that they may not be getting more than 2GB of VRAM (or its equivalent in DDR3 terms) and the card that is the best example of performance and ram quantity is GTX680. Utilizing the 4GB version is pointless.

I think it goes to show what the "next gen" visual fidelity needs in terms of VRAM.
 
#38
More RAM does not mean more open world games or better open world games. If anything good streaming engine needs faster RAM and fast HDD/SSD rather than more ram since it constantly load things. And then there is LOD which uses a lot of RAM. The more RAM you have the more things you will see in distance (considering you have fast RAM and good GPU+CPU combo to hold increased amount things to do).

Skyrim is rather bad example since it goes back to morrowind where normal loading between areas were common. Cells are essentially levels which are loaded one by one and that didn't change much in Skyrim or Oblivion. True streaming engine like Witcher 2 or Uncharted loads only things that players see without loadings.

There is a reason why top GPU always have fastest ram. When you will have next gen games with improved texture sizes, polycount etc then fast ram will be essential to provide good GFX.

That is pretty much the reasoning with open world games performing better with more RAM. I understand streaming, and GDDR5 would cause less pop ins, but at 70GB/s, it could in fact, be fast enough to not be an issue, especially when smaller textures like hair/fur, would be stored on the EDRAM, like in StarFox Adventures.

4GBs, would be fine for open world games, unless they are really pushing stuff, thanks to LOD. Skyrim for instance was 2GB limited on PC, and you had to edit a file to allow the game to use more system memory.
 

Stallion Free

Cock Encumbered
Jan 21, 2009
29,933
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Connecticut, U.S.
steamcommunity.com
#41
They don't have to since it's the logical explanation. Think about it: Agni's philosophy was designed to consume less than 2GB. Had they been using a 4GB card, that wouldn't have been the case. The next gen development knows that they may not be getting more than 2GB of VRAM (or its equivalent in DDR3 terms) and the card that is the best example of performance and ram quantity is GTX680. Utilizing the 4GB version is pointless.

I think it goes to show what the "next gen" visual fidelity needs in terms of VRAM.
Well that's depressing.

I mean once 4 gb becomes as common as 2/3 gb gdr5 cards we are gonna see people running sli/tri-sli set ups with 8-12 gb of vram alone. If I have cash to blow I'll probably do an sli set up for the 700 series of nv cards.
 
Feb 25, 2008
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#44
Well that's depressing.

I mean once 4 gb becomes as common as 2/3 gb gdr5 cards we are gonna see people running sli/tri-sli set ups with 8-12 gb of vram alone. If I have cash to blow I'll probably do an sli set up for the 700 series of nv cards.
WRONG. If you are using three SLI Cards with 4 GB of VRAM, you have a total of only 4 GB VRAM usable. It doesn't add up.
 
Jun 5, 2011
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#49
I'd personally go with the larger memory capacity, especially at ~70GB/s. That plus 64MB edram (which should handle 1080p frame buffers with AA or without + used for very fast access memory.

The main reason is open world games, if you want open world games, having more memory allows for this to happen, and you are still looking at 3X+ the speed of 360's memory with XB3's rumored RAM. That should handle 1080p fairly easily.

What you can do with GDDR5 is more AF and you can push the entire frame buffer to ram without seeing a hiccup compared to using the edram from microsoft. That would allow for more AA but the games would be relatively more "tunnel" like, still should be better than this generation in that regard, but XB3 could have a fairly even performance between "tunnel" designed games and open world games, though this is of course if they are limiting their tunnel games to PS4's smaller ram footprint. You'd probably see higher resolution textures on XB3 vs PS4, but PS4 would have better IQ so it could end up essentially being a wash.

As for OS, I would expect XB3 to use up to 2GB for their OS, they might shrink it overtime, but at launch, saving that much space even if they don't use it, would allow them to add features later.
So much wrong with this...

How are they going to get 70GB/s? Break it down.

Second, WTF does the RAM bandwidth have to do with open world vs linear level design? Care to explain? Open world games are not all loaded up into memory, they stream the same way that linear games do.