Betanumerical
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Wasn't KZ running on the old dev kits, which had 4GB's of ram over all?.
PlayStation 4 (codename Orbis) technical hardware investigation (news and rumours)
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Wasn't KZ running on the old dev kits, which had 4GB's of ram over all?.
All of the devkits with anything like final silicon have always had 8GB. They were planned that way even when the targeted memory was 4GB.
SCE indeed said in offcial pdf: 3GB of RAM is called Video RAM (VRAM), used by GPU. 1.5 GB used by CPU as system RAM and another 128 MB is shared RAM. At least KZ only had 3GB of VRAM.
What pdf? PS4 has unified memory; it has no VRAM. If you're talking about the KZ presentation, that's just the RAM Guerilla chose to reserve. Another game might allocate 1GB to graphics content, while another may assign 4GBs to graphics content.
There's no disclosed physical reason why GPU-allocated memory is limited to 3 GB. The way memory pages are used in already public APUs allows for the allocation to vary, with the caveat that the platform itself can impose a ceiling on what the developer is able to access in total.
I said "at least KZ only uses this amount". I means that I use KZ as an example to illustrate that a PS4 game like KZ, only uses 3GB as VRAM. Therefore PS4 has good bandwidth per GB because GPU only uses 3GB in this case and most of bandwidth 176GB/s may be used by GPU.
KZ pdf SCE said in KZ, GPU only uses 3GB (p.6), which is called VRAM.
http://forum.beyond3d.com/showpost.php?p=1773314&postcount=3024
So at one point in development KZ used 3GB for video, thus all PS4 games will use 3GB for video? I'm not following this logic either. There is a pool of of available RAM, devs cannot exceed a limit imposed by Sony and cannot exceed the available bandwidth imposed by the various physical buses (176GB/s theoretical aggregate max).
That's very different to your original remark, "But PS4 has only 3GB of VRAM". The 'video RAM' label is applied by Guerilla, not Sony or the hardware spec. The PS4 hardware has no such video RAM limit. That KZ uses 3 GBs for video stuff says nothing about other games. As I say, if a different game type entirely chooses to use 1 GB for graphics content, then it gets ~150x as much BW as it has 'VRAM'. Another game that uses 4.5 GBs of graphics content would have about 33.3x as much BW as 'VRAM'. The 'BW to VRAM' ratio isn't fixed in PS4, unlike graphics cards with hard VRAM.
Silent_Buddha
Legend
Yes, it's certainly a big problem and one that I noted before we had specs for this upcoming generation of consoles.
And while streaming may be the best overall solution, I'm not entirely onboard with it as even with SSD on PC, texture pop-in with streaming solutions is still quite evident, I can only imagine how much worse it will be with a 2.5" HDD struggling to stream that amount of texture data.
Hence I was thinking of some method where you have a reasonable load time to bring in some higher quality assets than the low quality blurry textures that are displayed before the full res texture is streamed in to at least mitigate the horrible appearance of blurry textures before the full res texture is available.
Regards,
SB
"But PS4 has only 3GB of VRAM (at least KZ only uses this amount)"
I means that at least KZ uses 3GB of VRAM; and this is one of few examples we know. I don't mean all PS4 games has 3GB of VRAM.
In the above example, KZ has about 50X of bandwidth to memory-size ratio. It is still good. For others games using less than 3GB VRAM, the above ratio can increase significantly,even larger than 100X; no matter 50X or 100X, it is good, and this is the key point what I was trying to say.
So if another game tries to access 4GB or more for GPU, then the bandwidth-to-size ratio can be less than 35X and I don't know if this is a good choice for game development.
Maybe he is referring to the frame buffer.
Should allow for some supersampling until TVs catch up in resolutionI'd like to see how large the resolution is to have 3GB worth of frame buffer
I'd like to see how large the resolution is to have 3GB worth of frame buffer
In AMD speak (kernel dev guide) the frame buffer refers to the portion of memory dedicated to the gpu when talking about an apu. When talking about a discrete card its the VRAM or device memory. I am guessing the Garlic bus facilitates accesses to this region of memory on an apu. While onion and onion+ plus facilitates memory accesses to what would normally be the system (host) memory in a discrete cpu and gpu setup.
The PS4 has access to 5.5-6 GB of GDDR5 that partitions a portion to what would normally be vram and a portion to what would be system memory for game apps.
I am not versed so I may be wrong and plus the PS4 hardware is not relatively defined.
That being said don't most high end PC games require more system ram (even when accounting for OS footprint) than video ram?
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Well..I'd like to see how large the resolution is to have 3GB worth of frame buffer
Dx11 maximum texture/buffer resolution is 16384*16384, so with a FP32 RGBA buffer you would use ~4GB of memory..
With fp16 you would need use couple of buffers to reach 3GB, but it shouldn't be a problem if you really want to go that far.
They do, but part of it has to do with using system memory for uploading/caching textures. On PS3 you should be able to do with alot leass duplicated GPU-Resources
Does the PS4 have any abstraction layers it has to work through which would prevent it from being as 'close to the metal' as devs are this generation?
During the Carmack's keynote I think I heard him say that they cannot get as close to the hardware this generation or something compared to the last gen due to this?
During the Carmack's keynote I think I heard him say that they cannot get as close to the hardware this generation or something compared to the last gen due to this?
PS4 has high and low level access.
Right.. But how 'low' is 'low' compared to say PS3? That's the point I was getting at.
AFAIK as low as PS3.
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