It's actually quite clear this function is handled by the VCE (video compression engine) and UVD (universal video decoder) blocks of the SoC. It would be kind of awkward to put it in some external chip with no direct connection to the framebuffer holding the data that needs to be encoded. And basically all recent GPUs of AMD contain these blocks (save for some ultra low end models).
PlayStation 4 (codename Orbis) technical hardware investigation (news and rumours)
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Deleted member 86764
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If not for the OS or compression/decompression, it's only used for DRM and help in preventing hacking of the system? If so, it seems strange that they'd use it as a selling point during the reveal. I agree it almost certainly isn't accessible by the devs, but it in some way may leave the SOC to concentrate more on games.
It remains a bit of an unknown quantity. I'm fairly sure that Sony are keeping it a secret for good reason. They've actually been MORE quiet on it since the initial reveal.
It remains a bit of an unknown quantity. I'm fairly sure that Sony are keeping it a secret for good reason. They've actually been MORE quiet on it since the initial reveal.
The background processor was disclosed as being able to manage downloads and updates. There is imprecise language as to its involvement in network download and upload traffic during gaming.
Fundamentaly, it seems to be capable of arbitrating traffic between mass storage, the network, and potentially the main SoC during gameplay. When the console not active, this processor may be capable of at least initiating downloads and udpates.
Without further public disclosure about the details of its involvement, I don't see a way to eliminate a number of very different possibilities for how this arrangement is implemented. Many of the possibilities do not require the game or application to know much, if anything, about the processor.
A bunch of those functions aren't glamorous, and there could be platform-specific security details, since this processor does appear to interact with some potentially sensitive system paths.
This may give Sony little reason to go into too much detail concerning a rather unexciting and anonymous device from a gamer's point of view, and a potential vector into accessing the OS or system functions for those not interested in buying games.
Fundamentaly, it seems to be capable of arbitrating traffic between mass storage, the network, and potentially the main SoC during gameplay. When the console not active, this processor may be capable of at least initiating downloads and udpates.
Without further public disclosure about the details of its involvement, I don't see a way to eliminate a number of very different possibilities for how this arrangement is implemented. Many of the possibilities do not require the game or application to know much, if anything, about the processor.
A bunch of those functions aren't glamorous, and there could be platform-specific security details, since this processor does appear to interact with some potentially sensitive system paths.
This may give Sony little reason to go into too much detail concerning a rather unexciting and anonymous device from a gamer's point of view, and a potential vector into accessing the OS or system functions for those not interested in buying games.
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Deleted member 86764
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You're probably right.
I'd have thought a tiny proportion of a single Jaguar core could be devoted to downloads and updates, even security. I'm not saying the chip is powerful in anyway, I'm certain it isn't. Just seems there's more to it, so that the system has a little competitive advantage. Especially is it had its own memory pool of slow memory.
Do we not think the GDDR5 pool is excessively fast for OS functionality? If you're going to consider as much as 2-3GB for the system, that's a big expense for something that'd be covered by much cheaper RAM.
I'd have thought a tiny proportion of a single Jaguar core could be devoted to downloads and updates, even security. I'm not saying the chip is powerful in anyway, I'm certain it isn't. Just seems there's more to it, so that the system has a little competitive advantage. Especially is it had its own memory pool of slow memory.
Do we not think the GDDR5 pool is excessively fast for OS functionality? If you're going to consider as much as 2-3GB for the system, that's a big expense for something that'd be covered by much cheaper RAM.
The ARM can run at very low power when the console is 'off'. I don't think the OS Processor has anything to do competitive advantage, but user experience with a consistent performance at various power levels. And it can handle security too, which is reason not to talk about it, as 3dilettante says.
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Deleted member 86764
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I'm thinking more along the lines of the reverse of what a current gaming PC would do. Normally a PC has a high amount of system RAM, with a comparatively small video RAM. What if the PS4 has a tiny system RAM and a high video RAM? Perfect for a gaming machine. The devs would never need know.
I'm probably in a dreamworld, but it's fun to speculate.
I'm probably in a dreamworld, but it's fun to speculate.
Sony's original bullet point was energy efficiency, particularly for a form of networked idle that allowed the background processor to download updates when the console was "off".
Depending on their energy ceiling, keeping the SoC idling for the same purpose could have been too high. Power gating for the CPUs is at a module granularity, with an uncertain amount of system RAM that has to stay at least minimally active. AMD chips with 100W or more TDPs can drop down to single digit watt ranges, but even that could be too high.
There's also a potential yield benefit, if the idle power range is a limiter. Leaky APUs that don't idle as low as the norm can still be considered good if the tiny background processor is all that matters at those power modes.
The downside to unifying anything is that you eventually wind up using the single resource for things that don't benefit from the full capabilities of it. Since it's fast, it shouldn't waste too much time on it.
Having a separate RAM pool in addition to the GDDR5 just for the OS doesn't sound like it saves money, however. Synchronization updates and system structures like page tables having to hop between pools can lead to performance regressions.
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Deleted member 86764
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If the secondary chip is only running downloads, updates and security, I doubt it'll need even 10MB of RAM. Maybe just a tiny cache.
Regardless, it'd be interesting to know more, even if just a confirmation that it's used for security measures.
Regardless, it'd be interesting to know more, even if just a confirmation that it's used for security measures.
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Deleted member 86764
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Just for the record; the image during the reveal gave the chip a complete slide unto itself.
"Secondary Custom Chip
Background Processing"
I completely agree that it's most likely for the items described above by 3dilettante, but interesting nonetheless.
"Secondary Custom Chip
Background Processing"
I completely agree that it's most likely for the items described above by 3dilettante, but interesting nonetheless.
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Deleted member 86764
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What chips do Sony use in their mobile chipsets?
I think Cerny said the secondary chip can access the GDDR5 memory.
No more information after that. :-/
Secondary devices, like disk and IO controllers, use DMA to work with main memory in PCs.
Since the secondary processor sits in the middle of things like the network and storage, both of which in another system could write to main memory, it makes sense that the background processor can.
That could be the weakest level of interaction through memory between the background processor and the CPU cores. It doesn't rule out tighter synchronization and sharing of the memory space, but the looser the coupling, the less the low level details on either side can affect one another.
Since the secondary processor sits in the middle of things like the network and storage, both of which in another system could write to main memory, it makes sense that the background processor can.
That could be the weakest level of interaction through memory between the background processor and the CPU cores. It doesn't rule out tighter synchronization and sharing of the memory space, but the looser the coupling, the less the low level details on either side can affect one another.
No more of that 14+4 and unbalanced system talk...
http://www.guardian.co.uk/technology/gamesblog/2013/jul/15/ps4-develop-2013-playstation-sony
http://www.guardian.co.uk/technology/gamesblog/2013/jul/15/ps4-develop-2013-playstation-sony
PSP uses custom Sony chip based on 32bit MIPS-architecture with some custom GPU and another custom Sony chip based on 64bit MIPS-architecture as the "media engine"
PS Vita uses 2GHz quadcore ARM Cortex-A9 with PowerVR SGX543MP4+
Their phones use with couple exceptions Qualcomm Snapdragons
Yes, I vaguely remember they said the GDDR5 memory will remain powered in low power mode. So the secondary chip should be able to access the main memory during that time too.
article said:
Haha, at least he's honest. They should reveal the info to people like DF instead.
Low level access for tweaking performance and utilization should be nice but what's exactly not round here ?
Love_In_Rio
Veteran
This is final kit?. 2,75 GHz and is representative of final console?. What?. Have they introduced turbo boost in CPU?.
The 2.75GHz "maximum clock frequency in the system" is clearly the WCLK of the GDDR5 running at the announced 5.5 Gbps. GDDR5 needs two clock signals to work, one at 1.375GHz and the other one at the mentioned 2.75GHz (for 5.5Gbps operation), which is likely the highest clock in the system, not the CPU clock.
arijoytunir
Regular
what is the "cell" clock speed in ps3 dev kit ? is it the same 3.2ghz or higher ? or has ps4's cpu been upclocked?
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