Albofighter
Newcomer
Ihere said sonys target has been 192 GB/S (assuming 4 gb ram) since 2011 but not sure if thats gdrr5 http://www.neogaf.com/forum/showpost.php?p=46846238&postcount=157
PlayStation 4 (codename Orbis) technical hardware investigation (news and rumours)
- Thread starter Love_In_Rio
- Start date
- Status
Ok. But I think you overestimating engenering cost of memory side. I thought previous prototypes of ps4 (feb 2012) was designed with 2 GB, and then sony changed it to 4 GB (oct 2012 I think). So if design is not so final, they could change things. It's more realistic than ddr4 which is nowhere in a wild, and which production could be unpredictable in cost and supply.
dagnastyep
Newcomer
2, 4, 8GB of GDDR5 = 256bit memory bus. 3, 6, 9 = 384bit memory bus. They'd basically have to rework the whole chip to go from 4 to 6GB. Not going to happen.
I just want to know what those 16GB devkits were used for, if they exist.
Bagel seed
Veteran
I think lherre is just one of those low tier multi devs I was hypothesizing about before, the ones stuck with the gimped kits. Ubisoft Spain right? Not an impressive games list. But like he said, he doesn't know or can't say if it's changed or not.
Silent_Buddha
Legend
Going from 2 GB to 4 GB of GDDR5 is relatively easy. The bus width doesn't change, you just use higher density memory.
Going above 4 GB of GDDR5 means changing the bus width which means changing your memory controller which means changing your CPU design.
It isn't cheap and it isn't easy.
Regards,
SB
BTW how bus width calculated? What if I want 5,5 GB for my specific config?
with the clamshell mode and 16bit mode of GDDR5 chip you can simulate 1GB 32bit chip with two 512MB chip (front side and back side PCB) without modify memory controller or PCB print. it seem you can double RAM capacity at the last moment
Last edited by a moderator:
Bagel seed
Veteran
According to Sweetvar in Oct, there was a 6 month delay in the production for Sony's chip at AMD. But it was still ahead of MS's at that time. So something happened, which could account for possible changes to fit a memory increase. 6 months is a long time.
My insider information tells me they were for either one of two things. The special sauce theory was:
The extra memory balanced the system so it would not tip over, spilling the coffee.
The more benign theory floated, which doesn't seem likely, was the Orbis devkits were used to, hold onto your hat, make games
Perhaps this is a silly question so excuse my ignorance but could you design a controller capable of supporting 8GB and test out 4GB and depending on performance up the ram later?
temesgen, we don't even know if there was a SoC spun that only supported 4GB. We know there have been devkits with discrete GPU boards and rumors of lower end SoCs.
Orbis likely will have 4GB of memory, if it was designed for GDDR5, for the reasons I noted earlier. But there is no need to speculate about a revised memory controller and major changes if, indeed, the devkits were using discreet GPUs.
Like I mentioned earlier people are taking devkits (which are glorified PCs) and rumored specs and then looking at "changes" to the plan. For pete's sake, the Xbox 360 started off with some G5's and Radeon 9800 Pros and moved onto some X800s -- that doesn't mean MS "changed" the design.
I agree its highly unlikely the ram would be boosted if it required a redesign of hardware; that is why I am asking the question. Could a controller designed to handle 8GB work with only 4GB present on the kits?
edit: just reread - nvm my post
yes 256bit controller can support 4 or 8GB GDDR5 and devkit seem already 8GB
http://www.vgleaks.com/orbis-devkits-roadmaptypes/
http://www.vgleaks.com/orbis-devkits-roadmaptypes/
Silent_Buddha
Legend
The dev kit likely has 8 GB of DDR3 combined with the discrete graphics card with 2 or 3 GB of GDDR5.
All 3 of those devkits in that link of yours uses a discrete graphics card. It's possible the discrete graphics card may have 4 GB of GDDR5, but I'm not sure Sony would want to pay that much for a limited run development kit. Custom firmware (as mentioned in the link) is relatively easy. Custom GDDR5 amount for a one off discrete graphics card to only be used on the pre-release dev kit would be much more costly.
Regards,
SB
Well, maybe: 8GB = 4GB for games (as in console) + 4GB for debug and dev tools...
no the last devkit (named "SoC based devkit") use the final SoC and GDDR5 of course (no discrete GPU, no DDR3)
Silent_Buddha
Legend
Whoops yeah, I didn't scroll down far enough.
Either way, 8 GB on the dev kit pretty much guarantee's that it'll be 4 GB on the console. If the console will be 8 GB, then the dev kit would likely need 12-16 GB for development.
And ignoring the whole what is possible. Another 4 GB of GDDR5 would add at least another 80 USD onto the BOM (at least according to the only thing we have to go by, which is AMD's BOM cost for GDDR5 in 2011). Even if it was half of that, 40 USD, that would still be too expensive, IMO. 80 USD (if GDDR5 was as cheap as 10 USD per GB) would potentially be more than 1/3 of the total BOM dedicated just to memory, assuming a targeted price point of 299 USD for the base model. 1/4 of the total BOM if 399 USD is the target for the base model.
Regards,
SB
- Status
