We've started to order things!


The heat pad that connects the SoC to the PCB (which has copper layers for cooling) is also not yet installed and an aluminium plate will be installed as well behind the SoC.

I don't think that any of us have ever seen this combination. This is the first I recall seeing mention of the aluminum plate - though I could have just missed it.

I'm assuming that since the plate would rest between the SoC board and the case plastics that it would have been taken into account in the mold generation. Does it connect over to the SD cages?

Some time if/when you have the chance, a few pictures of all of the pieces (including the heat pad(s?) and aluminum plate) and how they go together would be fascinating.
 
I'm assuming that since the plate would rest between the SoC board and the case plastics that it would have been taken into account in the mold generation. Does it connect over to the SD cages?
I don't have a reference right now, but ED said a long time ago that the cooling solution for the SoC would connect to the SD cages. This makes some sort of heat sink necessary and while he's at it it would only make sense to expand it over as much of the footprint of the Pyra as possible.

I'm not sure how well that would work, but it might even be worth considering to put some larger heat sink element in the empty lower front left corner. Since the plastic case would still block the heat dissipation I'm not sure if it would be better to design it like a traditional heat sink with a lot of surface area, or if a solid block of aluminium would make more sense, so it would be more of an actual heat sink to absorb thermal peaks instead of a heat dissipator.
 
I'm not sure how well that would work, but it might even be worth considering to put some larger heat sink element in the empty lower front left corner.
Don't fill that corner - it's where the longer RHS extends into. (Red Hot Stylus - side experiments of mine.)

Since the plastic case would still block the heat dissipation I'm not sure if it would be better to design it like a traditional heat sink with a lot of surface area, or if a solid block of aluminium would make more sense, so it would be more of an actual heat sink to absorb thermal peaks instead of a heat dissipator.

Which raises the question again of how to get the heat out of the case instead of just adding places for it to accumulate.

I've had this idea/fantasy of someone, someday, making a CNC milled aluminum replacement for just the lower case plastics. It could then act as both a much larger heat sink and a liquid cooled heat exchanger - to the user's hands. (Don't panic - it would not be that hot once spread to that material volume.) I don't really think that such exotic solutions will be necessary. It is more of a mental exercise in how a Pyra form factor could work with a much hotter running SoC.

I wonder - Does the @zmatt prototype have the thermal pad & AL plate thermal solutions in place?

This project keeps getting closer to reality. I'm really looking forward to the next round of updates.
 
Has ED ever indicated how much a replacement CPU/RAM/emmc board would cost say given the current chipset as an example?

I know it would depend on future chipsets chosen, but I guess an indication using the cost of the current SOC , RAM and emmc would be good. My guess would be around $150 - $200 given the over $50 cost just for the Omap 5 SOC. OF course then there is the RAM, the emmc , the board coast and the population , contingency etc. Plus then add wholesale and retail markups.
 
I think I recall ED predicting future SoC builds could cost less than 100EUR to the end user.

Regarding ED's cooling solution, I'm a little confused by 'the head pad that connects the SoC to the PCB'. I'd have thought the SoC would be soldered to the CPU board PCB, and a sticky heat pad would be required on top of it to connect to the aluminum plate that would connect to the SD card cages and make them part of the heat sink, and potentially also radiators to the outside of the case.

Edit: I think this is the source of ED's estimate: https://pyra-handheld.com/boards/threads/snapdragon-soc-410e-and-600e.78238/#post-1394120
 
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I think I recall ED predicting future SoC builds could cost less than 100EUR to the end user.

Regarding ED's cooling solution, I'm a little confused by 'the head pad that connects the SoC to the PCB'. I'd have thought the SoC would be soldered to the CPU board PCB, and a sticky heat pad would be required on top of it to connect to the aluminum plate that would connect to the SD card cages and make them part of the heat sink, and potentially also radiators to the outside of the case.

Edit: I think this is the source of ED's estimate: https://pyra-handheld.com/boards/threads/snapdragon-soc-410e-and-600e.78238/#post-1394120

To be fair, that was for a cheaper lower power SOC, and even then it was a big if - ie if it the SOC was cheap
 
Regarding ED's cooling solution, I'm a little confused by 'the head pad that connects the SoC to the PCB'. I'd have thought the SoC would be soldered to the CPU board PCB, and a sticky heat pad would be required on top of it to connect to the aluminum plate that would connect to the SD card cages and make them part of the heat sink, and potentially also radiators to the outside of the case.

The SoC gets sandwiched between the CPU board PCB and the Main board PCB - the heat pad in question would transfer heat to the exposed copper on the Main board PCB, effectively turning the Main board itself into a heat-sink.

I'm having trouble picturing where the aluminium plate fits in though.

-Neelix
 
The SoC gets sandwiched between the CPU board PCB and the Main board PCB - the heat pad in question would transfer heat to the exposed copper on the Main board PCB, effectively turning the Main board itself into a heat-sink.

I'm having trouble picturing where the aluminium plate fits in though.

-Neelix

I believe that the aluminum plate would go on the back side of the SoC between the SoC and the case plastics. So, from the desk up:
Battery door, battery, lower case plastics (including stylus holder & stylus), aluminum plate, SoC, thermal pad, main/peripheral board, key mat, keyboard surround, screen bezel, screen, screen back light board, plastic lid illumination piece, screen outer lid, glue, aluminum logo plate.
 
Note that the second 4GB of memory technically resides at 0x200000000, although using 0x300000000 like igep does works too since the excess row bit is ignored by the memory hence the two regions are aliases.

Hey cool good to hear you figured it out! The aliases should be just fine, I think the only advantage for not using the aliases
would be with IO-coherent C-A15 hardware like mach-keystone. But that requires extra hoops for the addressing like
keystone does, and 5432 never was wired to be IO-coherent AFAIK.

I've also uncovered the mystery of the stolen memory at 0xFF000000

OK good to hear we could reclaim that, it's after all 16MB which is quite a bit of memory. The cpu1 startup address pointing
there worries me a bit though if there's some save/restore code relocated there.. I'll try to verify that. So maybe let's reclaim it a
bit later after things really are verified to be working. We don't have much PM yet happening for 5432 in mainline kernel.
 
The aliases should be just fine, I think the only advantage for not using the aliases would be with IO-coherent C-A15 hardware like mach-keystone. But that requires extra hoops for the addressing like keystone does, and 5432 never was wired to be IO-coherent AFAIK.
Thank god it isn't, the cortex-A15 was ARM's first processor supporting a coherent interconnect and it has several "category A" bugs related to it. (e.g. #781819: "If the above conditions occur, the A15 will deadlock." .. "There is no workaround in a coherent ACE system.")

The cpu1 startup address pointing there worries me a bit though if there's some save/restore code relocated there..
That just can't be right. With LISA setup like this, any access to (phys) 0x00FF000000-0x00FFFFFFFF would result in a bus error.
 
It's been 2 weeks since the last news post...

66511846.jpg

:D
 
I believe that the aluminum plate would go on the back side of the SoC between the SoC and the case plastics. So, from the desk up:
Battery door, battery, lower case plastics (including stylus holder & stylus), aluminum plate, SoC, thermal pad, main/peripheral board, key mat, keyboard surround, screen bezel, screen, screen back light board, plastic lid illumination piece, screen outer lid, glue, aluminum logo plate.
What about the air?
 
if you've read the posts lately you would have seen they may have figured out the 4gb ram issue. to me that's a new news post
This is true, but things like that can be easily if one isn't regularly scouring the threads.

A picture tells a thousand words though ;-)
 
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