Why does PS4's low power mode still need a fan?

Shifty Geezer

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It's presently hot here, 27 degrees C outside. My PS4 is in low power mode downloading Elder Scrolls and the friggin' fan is on blowing out hot air. Why?! Surely it's just a few watts of ARM processor like any mobile device downloading, with a bit of HDD. I've disabled all options other than keep connected to internet. Why's it so stupidly power hungry and heat generating doing nothing?
 
It's presently hot here, 27 degrees C outside. My PS4 is in low power mode downloading Elder Scrolls and the friggin' fan is on blowing out hot air. Why?! Surely it's just a few watts of ARM processor like any mobile device downloading, with a bit of HDD. I've disabled all options other than keep connected to internet. Why's it so stupidly power hungry and heat generating doing nothing?
If it's downloading stuff then the whole Jaguar CPU is on because ARM alone is not enough to download stuff. The fan will eventually stop when download will be over (and USB deactivated on some PS4 models).
 
The ARM doesn't handle background downloads?! Why not? I thought that was its purpose.

edit:
http://www.dualshockers.com/ps4-con...-uses-the-main-apu-and-not-just-the-arm-chip/

Ito-san explained that initially Sony attempted to have background download performed exclusively by the secondary sub-system ARM chip (as it was announced during the console’s presentation in February), in order to keep the main APU powered down, but that proved not to be fully possible.

The download process is too heavy for the ARM chip alone, so the Jaguar-based CPU of the main APU (Accelerated Processing Unit, that includes CPU and GPU) is called into action to do the heavy lifting and protocol processing.
Seems bonkers to me. How does XB1 fair with the same task?
 
Xbox can only download one game at a time (like PS3) but it still has to use the Jaguar for this.

My theory is that Sony couldn't use the ARM alone because the PS4 can download several games / updates simultaneously.
 
Xbox can only download one game at a time (like PS3) but it still has to use the Jaguar for this.

My theory is that Sony couldn't use the ARM alone because the PS4 can download several games / updates simultaneously.

Marvell processors like the one in the PS4 are used in NASs. The hardware itself should be more than capable of what it would have to do to enable this.
 
If it's only for the duration of the download, I don't really think this is a problem.. unless you're on a 5-10Mbit connection and you'd take an entire day to download a ~50GB game, it's not like the PS4Bone is going to make any significant change in the electricity bill.



Much worse than this is the stupid PSVR processing unit that needs to have its fan turned on the whole time just to get normal HDMI passthrough to the TV without using the VR headset.
 
If it's only for the duration of the download, I don't really think this is a problem.. unless you're on a 5-10Mbit connection and you'd take an entire day to download a ~50GB game, it's not like the PS4Bone is going to make any significant change in the electricity bill.



Much worse than this is the stupid PSVR processing unit that needs to have its fan turned on the whole time just to get normal HDMI passthrough to the TV without using the VR headset.


It's not a big deal, but it does make you question the utility of having the secondary SoC vs. just having a standard southbridge. I guess it does still relieve some memory/processing overhead from the main system. I'm more baffled that they couldn't make it work as originally intended.
 
Yeah, it's odd that they couldn't get it working after 4 years. It's the kind of issue that I expected at launch, but that's egregious now. Especially when my phone doesn't need a fan.

I'm still using my launch PS4 and it's noisier than it should be when it's in rest mode and only downloading.
 
Xbox can only download one game at a time (like PS3) but it still has to use the Jaguar for this.

My theory is that Sony couldn't use the ARM alone because the PS4 can download several games / updates simultaneously.

So, the PS4 doesn't simply queue titles and downloads content simultaneously?

Why? What's the benefit?
 
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It's not a big deal, but it does make you question the utility of having the secondary SoC vs. just having a standard southbridge. I guess it does still relieve some memory/processing overhead from the main system. I'm more baffled that they couldn't make it work as originally intended.

I think it would be interesting with some of the low-level knowledge of what Sony intended to say whether this scheme saves much processing overhead in a more standard arrangement than the PS4.

A big chunk of what it's doing is abstracting IO, acting as the handler for system devices, running its own OS, quality of service, and storage management/encryption. That can be decently complex, but from the looks of things it is doing a lot of work because Sony wanted this work duplicated and run through its esoteric system architecture.
How much of the work "saved" from the main system just wouldn't be there if the attempt at saving it wasn't made isn't clear.

The PS4 jailbreak seems to indicate that Sony had some oddly roundabout ways of getting things done, and part of its flaky security model is to apparently baked into the isolation of the APU and its OS from a lot of this work.

Given the limited power of the southbridge, Sony may have underestimated the performance needed for timely handling of data, decrypting, firing up devices, processing, running its OS, re-encrypting, and installing updates.
This could be doable with the chip in question, but perhaps not in the case of doing so when this chip is also navigating the system hierarchy that is also plugged into an x86 chip, suspend mode, and yet another OS--all of which might need to be updated from an arbitrary version, partly active, or could be woken up at very inconvenient times.

Perhaps that could be doable, but perhaps not without system software that is sufficiently robust or optimized, and Sony's shown signs that they are not fully up to that task.
Further up from that, it might not be within Sony's grasp to be able to get even a non-optimized but functional software stack for background updates.
The wake-up process, system management, and network+install processing stack for the PS4's fully-on APU mode is by necessity the one that already needs to be functional, and it has the performance to help brute-force kludgy workarounds--and that is the one path they could get to work. There's possibly more help available in the side of the system that has more standard hardware and isn't wholly super-proprietary.

The PS4 hack wasn't that complimentary on the quality of Sony's work. (edit: the presentation on it) Some of it was bewilderment which might not be entirely fair in its evaluation of what Sony was doing, but there's a lot that seems to be band-aids and less than successful internal development going on.
 
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If it's only for the duration of the download, I don't really think this is a problem.. unless you're on a 5-10Mbit connection and you'd take an entire day to download a ~50GB game, it's not like the PS4Bone is going to make any significant change in the electricity bill.
It's not the bill I'm worried about, but the fact I have to leave my PS4 on for 17 hours with it dumping extra heat into an already unpleasantly hot room. The question arises 'why is this?' when technically there seems no cause for it.
 
So, the PS4 doesn't simply queue titles and downloads content simultaneously?

Why? What's the benefit?
No benefit. In fact it's just screwed me over. 8 hours to go last night. Left PS4 downloading overnight. This morning - 9 hours to go because it suddenly decided to download two other PS+ titles I added ages ago. How insanely stupid is that? Why not finish the current download? Why not make a start on the other downloads any time in the earlier 12 hours of downloading so I could stop them?

Edit: Even more stupid! Go to switch off PS4 so I can free up the internet for more important things and it's downloading Tales of the Borderlands which I added ages ago but never bothered to download until now. So it added another thing from my queue completely randomly. And then there's no clear 'download queue' option anywhere in the interface because it's a load of pizzle. I go into notifications to look up ESO download state and click that to get to other downloads. What a stupid OS! A big long string of game icons and inaccessibility to anything useful, jumping through hoops and layers of navigation to get anything done, and requiring 70W to do what a Surface Pro 4 can do in 10 and an Android tablet can do in 2. Very unimpressive.
 
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I found it totally stupid too when I found out my original PS4 kept whirring even in rest mode. I haven't heard the Pro doing that, so maybe they fixed it.
 
I found it totally stupid too when I found out my original PS4 kept whirring even in rest mode. I haven't heard the Pro doing that, so maybe they fixed it.
That's interesting but based on DF findings, Pro still need Jaguars in order to download stuff while in rest mode:

Rest Mode (Online, Downloading) Pro: 58W, PS4 2000: 46W , PS4 1000: 73W

But Pro (and PS4 newer models: 1.2 and slim 2000) need less energy during this mode so the system may not need the fan. What model of PS4 do you have Shifty ? You'd need only 46W if you had a slim model.
 
How insanely stupid is that? Why not finish the current download? Why not make a start on the other downloads any time in the earlier 12 hours of downloading so I could stop them?

It's been like thst since launch. Sony allegedly fixed it in the previous major update when they changed the PS4 UX a bit, but in reality, it doesn't.

PS4 also need 2x space to install game update. It also took ages just to "verify" game data when updating.

All of those happens even when ps4 is fully powered on. No wonder the arm chip can't handle background downloads when on rest mode.

Even kn full power mode, downloading stuff is already a mess
 
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