loekf
Regular
Yes, USB 3.0 hub controller. Appearently no on-chip PHY + controller in the south bridge. Further a Macronix 2 MB NOR flash and some SDRAM. Front-side has 256 MB NAND flash (also Marconix/Spansion).
PlayStation 4 (codename Orbis) technical hardware investigation (news and rumours)
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Yes, USB 3.0 hub controller. Appearently no on-chip PHY + controller in the south bridge. Further a Macronix 2 MB NOR flash and some SDRAM. Front-side has 256 MB NAND flash (also Marconix/Spansion).
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Deleted member 86764
Guest
Is the 2Gb DDR3 SDRAM for the secondary processor? I would presume so given its physical location. I wonder why it needs that much, weren't we assuming the chip would only use the GDDR5?
Betanumerical
Veteran
2Gb of DDR3 is probably very cheap, and low power. If it also handles the security functions, it having its own seperate physical ram and address space isn't a bad idea either.
loekf
Regular
I noticed that the guys from iFixedIt didn't find a seperate chip/ASIC for the 2nd processor. Maybe it's hidden in the southbridge (I/O) chip ?
loekf
Regular
I noticed that the guys from iFixedIt didn't find a seperate chip/ASIC for the 2nd processor. Maybe it's hidden in the southbridge (I/O) chip ?
EDIT: I was kind of right/wrong, there's:
- SCEI CXD90025G Secondary/Low Power Processor for Network Tasks
- SCEI 1327KM44S
From the type numbers, looks like the first one is the southbridge (guess SPDIF, I2S, I2C etc) incl. an ARM chip working off 2 Gb DDR SDRAM.
EDIT2:
- So we have an USB 3.0 hub between the actual USB 3.0 PHY on the southbridge and the USB ports on the front of the casing. Meaning the single (?) 5 Gbps USB 3.0 from the
southbridge is split into two USB 3.0 ports up front.
- Either they didn't want to spend the money on two USB 3.0 PHYs in the southbridge or they couldn't get compliant USB 3.0 PHYs.
- I wonder whether these ports are USB 3.0 compliant, so delivering 900 mA each (=> faster charging of your DS4).
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Deleted member 86764
Guest
I'm certain your assumption is correct, it just seems a lot for the security functions alone.
512MB is the same as the total PS3 memory size.*
It's a shame Sony didn't increase the chip and memory size so that it could function as the OS. At least then the games would have the full eight threads and 8GBs for GDDR5.
EDIT: *My mistake, the there's 256MB of DDR3
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Betanumerical
Veteran
That would have been interesting. There are arguably a few functions that would have had to run on the jaguar cores as they could not be done outside of them, but they could have trimmed it down to probably a fraction of a single core with a much larger secondary chip for the OS.
loekf
Regular
When you look at the Apple TV they could have run the OS + GUI on a single core Cortex-A9 + somewhat decent GPU @ 1080p. Shouldn't be that expensive in terms of real estate.
I think a gaming console OS could easily fit in 256MB, considering a modern, advanced multitasking OS like iOS runs comfortably on devices with 512MB total memory. Anyway, keeping the OS entirely off the jaguar cores may not be practical as the ARM CPU is bound to be rather slow and already has other tasks to watch over, and typically you need an OS kernel running on all CPUs in a multi-processor system anyway to handle task scheduling if nothing else...
I wonder where the constant gameplay recording is stored. 512MB would be enough.
They could have placed VitaSoC there [entire stack with 512MB of ram + 128MB of Vram], and created more robust OS that uses all 4 ARM cores.
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Deleted member 86764
Guest
Then it's no great surprise that the PS4 outperforms the Xbox One to such a degree. A lot of the Bone's chip size is down to the on chip memory, which is there to make up for the GDDR5 deficit.
The Vita SoC is designated CXD5315GG whilst the PS4 is CXD90025G. Now wishful thinking would whisper that including the VitaTV SoC in the PS4 would be ideal. Something they wouldn't shout from the rooftops if they haven't got the software working in time.
But then again wishful thinking would give me a Terabit 24/7 connection to Watson for all my cloud needs!
*(i)
So the MB has the 8GB of DDR5, 256MB of DDR3, and 32MB of flash. Is that right?
They may have put something similar to Vita's SOC but with slightly more powerful RAM as in the DDR3 we see above in there, at reasonable cost. This also corresponds with many leaked reports of what we saw of ORBIS having an additional ARM based chip.
I wouldn't be surprised if Sony has in fact pulled this off. It makes perfect sense if you take into account having to put all your OS resources into working on complementary architecture for both Vita and PS4.
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Deleted member 86764
Guest
Get ifixit on the just released (in Japan) VitaTV. I agree that it would be very unlikely though.
The system services like the sound engine and DRM should still be close to the cores that would be using them for latency purposes, and the memory reservation that is actually there for the OS is likely much smaller than the walled-off memory Sony currently reserves.
Moving the OS off on its own on a slow secondary core with slow memory would increase the overhead of each OS call.
So you'd get maybe a core and possibly a few hundred megabytes back, but then every other core and the GPU are going to take long round trips out to a slow OS chip in order to perform priviledged operations or synchronize with the system. It's more difficult to maintain quality of service if checking with the arbiter of QoS is itself a significant detriment to it.
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