bensimmo wrote: ↑

Fri Nov 22, 2024 6:27 pm

But given hours isn't an SI unit, as it should be seconds, who cares, not the people who print these things out.
kWs

While not defined as an SI unit, it is used and described in official SI literature with a defined abbreviation of lowercase h.

Paul Hutch wrote: ↑

Sat Nov 23, 2024 1:01 pm

bensimmo wrote: ↑

Fri Nov 22, 2024 6:27 pm

But given hours isn't an SI unit, as it should be seconds, who cares, not the people who print these things out.
kWs

While not defined as an SI unit, it is used and described in official SI literature with a defined abbreviation of lowercase h.

I always thought W was capitalised because James Watt is someone's name.

Back on topic, does anyone have a Pi 5 that mounts a Samba share from a Synology NAS? The post

Paul Hutch wrote: ↑

Sat Nov 23, 2024 1:01 pm

bensimmo wrote: ↑

Fri Nov 22, 2024 6:27 pm

But given hours isn't an SI unit, as it should be seconds, who cares, not the people who print these things out.
kWs

While not defined as an SI unit, it is used and described in official SI literature with a defined abbreviation of lowercase h.

I always thought the W was capitalised because James Watt is someone's name.

Back on topic, does anyone mount a Samba share served by a Synology NAS to a Pi 5? The thread

viewtopic.php?t=379329

indicates that recent versions of Raspberry Pi OS hang when transferring 20 GB of data from the 2GB version of the Pi to the NAS. My conjecture is resource exhaustion, perhaps caused by memory fragmentation or a leak, is responsible for the hang. A Pi 4 is also affected in the same way. The Bullseye release of Pi OS for the Pi 4 is not.

It would be appreciated if anyone with a 2GB Pi that mounts a Samba share served by Synology NAS tried to reproduce the hang.

davidcoton wrote: ↑

Fri Nov 22, 2024 4:27 pm

bjtheone wrote: ↑

Fri Nov 22, 2024 1:16 pm

apparently electricity is like magic

As a degree-level Electrical Engineer, I can confirm that electricity is magic (refer to Asimov on "sufficiently advanced technology"). 8-)

As a fellow degree-level EE P.Eng, I get that complex power stuff is well complex. However, the volume of myth and BS about simple stuff astounds me. Simple DC power stuff can all be sorted with Ohm's law and residential house wiring is... well... simple. People talk about the risks of replacing switches/plugs like you are talking about servicing a substation. Especially over in the colonies, you really have to work at managing to off yourself downstream of the panel.

calcvat wrote: ↑

Thu Nov 21, 2024 7:37 pm

It's interesting how we produce a high-quality, fully compliant power supply for just 11ドル.60 (including VAT) in the UK, yet some people still choose other options to save only a pound or two. That’s less than the price of a cup of coffee. I can somewhat understand if someone already has a power supply, but still, it’s surprising!

I explain why people complain about that:
The RPi5 is the second item, in more than half century using electronic devices, that does erratically when not in its original supply. and the other ore did not worked properly with all peripherals connected, but looking better in the box i found a power supply that was not advertized when selling it [so i had it without paying it separately nor having to order it].
So "normal" people do not order an extra supply when they already have plenty of them. (expecially when they do not buy a kit since plan to put the board on a specific case, have already the external memories, cables so as me ordered only the board and the active cooler)
later they find the fussyness of Pi5 but is was late.
Here getting one of such specific supplies cost 16,ドル that is not completely absurd [even if I have plenty of 3A ones, even a 5A one, that however is not PD compliant so it is refused]. the problem is that there are only three distributors, only by email order, and each one of them ask for a minimum order of 40€ or at least 6€ additional for shipping.
Se people is even more unhappy, since they feel exploited.
RPL should do one thing: offer to all orphan of the 5A PSU the opportunity to order one with free delivery at a local pick-up point [that is another problem: normal delivery happens at random time dropping the package, and it is not infrequent that are stolen on the way, i normally order only with suppliers that offer this service, so I am limited to Amazon and temu only)].
this would make people happy and they gain for trust.

--
Leonardo
mailto:[email protected]

There are a number of incorrect statements in your post.

The Pi 5:

* can run just fine off a 5V/3A supply (aka an official Pi 4 supply or any other USB-C spec complaint supply), under most use cases
* can run just fine off a 5V/5A non USB-PD supply, under all use cases
* can run just fine off ANY USB-PD supply since 5V/3A mode is required to be spec compliant, under most use cases
* can run just fine off its official USB-PD supply, under all use cases

What the Pi 5 cannot do is pin the CPU while delivering 1.6A to the USB ports while powered by a 5V/3A supply. However this is not a particularly common use case. Having played with this a bit you can "cheat" and override the port current limiting to get more current to the ports, while using a 5V/3A supply, as long as the Pi is lightly loaded. This will likely come back and bite you if you have variable cpu loads.

Perhaps you have been much luckier that I or lead a much more electronic widgetly sheltered life. I have encountered devices that appear to be powered via a USB port of some description that do not actually like USB spec compliant supplies. Even more special were the devices that came with what looked like USB supplies, that delivered voltages higher than the USB specs. I also have lived the russian roulette days of the barrel connectors of many sizes, with different voltages and polarity configurations. I especially hated those power supplies.

The Pi 5 will work with any USB-C spec compliant power supply under most use cases. It will work with a USB-PD power supply under most use cases. Note these are different. It will work with any power supply (USB-PD or non USB-PD) capable of delivering 5V/5A under all use cases. That means that any spec complaint USB-C connectorized power supply will work for most use cases.

This only leaves out the older USB supplies, since magically attaching a USB-C terminated cable to a 2.5A or lower supply is not going to turn it into a 3A USB-C supply. It is also not going to turn an older, non spec compliant steaming pile of crap into a spec compliant USB-C power supply. The biggest issue is that many old USB "power supplies" were intended to be used as device chargers and function differently, since they do not require good regulation and the ability to deliver max rated current at max rated voltage. These "supplies" work great as phone chargers, but they suck as power supplies. This is the biggest driver of the mantra of "do not use phone chargers". All power supplies that have a USB-A port on them are NOT the same.

Also, crap power supplies issues are a pita to troubleshoot, unless you have a decent storage scope. My time and avoiding frustration are worth way more than the price of a decent power supply.

Most of my newer Samsung phone "chargers", which are reasonably well designed 5V@3A supplies, happily powered my Pi 5. Same for my various USB-PD laptop "chargers" as well, including one that would not power a Pi 4. However, if a single mode supply does not claim 5V@3A you almost are guaranteed to have issues. My original Pi 5 desktop setup ran off pass through power from a 2.5A rated AMP+ HAT (which I suspect was conservatively rated), even when it was booting from a USB connected SATA SSD.

So I just don't get all your angst.

When I added a NVMe SSD BASE, I needed to switch to a 5A supply to get stable operation. I choose the official supply since it was the cheapest option to buy. The setup now has a SSD BASE and an audio HAT and works flawlessly.

wooly wrote: ↑

Thu Nov 28, 2024 7:43 pm

So "normal" people do not order an extra supply when they already have plenty of them.

That is incorrect.

Normal people first find out if the power supplies they already have laying around will work or not, then make an informed decision to either order the proper supply with their pi or not.

It is uninformed people who do not order things they don't know they will need.

memjr wrote: ↑

Fri Nov 29, 2024 3:10 am

wooly wrote: ↑

Thu Nov 28, 2024 7:43 pm

So "normal" people do not order an extra supply when they already have plenty of them.

That is incorrect.

Normal people first find out if the power supplies they already have laying around will work or not, then make an informed decision to either order the proper supply with their pi or not.

It is uninformed people who do not order things they don't know they will need.

According to the canine coder whether it's normal to make informed or uniformed decisions depends on the particular human.

One of my main concerns for making a two-drive Pi-based NAS is the power supply. However, how to properly cool a case made out of porcelain tile is also a blocker.

I'm hoping Santa comes up with a solution.

ejolson wrote: ↑

Fri Nov 29, 2024 3:20 am

One of my main concerns for making a two-drive Pi-based NAS is the power supply. However, how to properly cool a case made out of porcelain tile is also a blocker.

I'm hoping Santa comes up with a solution.

Santa will not come up with an efficient Pi-based architecture for NAS. Also not in history (10+ years back to the first RPi). Those BCM SoCs have only SDIO/MMC for storage, the rest is glue- or I/O- logic. That is why I bought BananaPi (Pro, M1+) after my first Pi1B. It has SATA on-chip and connector on-board (also a power connector, only 5V though). Same as with all credit-card sized boards, only the less power-hungry 2.5inch devices work. I have an old Sandisk SSD rated 0.6A, that worked/works. But it is more interesting to use for large 3.5inch HDD, although it is only SATA2 and 2xCortex-A9, it has Gbit RJ45. As you know, 32-bit cannot handle >8T for Btrfs, so a 64-bit CPU is what I need. Or 'SAN', testing that now.

A bare BCM2712 with 2-lane/4lane M.2 for NVME SSD and a PCIe-SATA3 chip and PCIe-ethernet 2.5Gbps RJ45 world be great as I don't see what I should do with the RP1 chip. But of course this never happens as RPL's hope should be RP1 I guess. Otherwise everyone can see that RK35xx SoCs have multiPHY PCIE/USB3/SATA lanes so plenty of single SoC boards that can do NAS.The most obvious one is Odroid-M1, although also that one has no 12V for HDD and CPU is only Cortex-A55. Fast enough for NAS 1Gbps, but people always want the fastest/overkill.

So it seems there is no sub-100 dollar Arm SBC that can also feed a high-end NVME + a large 3.5inch HDD from 1 PSU. I have some old PSUs with molex connector (both 5V and 12V). I think the 5V is good enough to power a low-end Cortex-Axx based SoC, that is the least amount of work. At least less complex than BCM2712<->PCIbus<->RPT1<->USB3connector/cable<->USB_SATAchip<->HDD (excluding power wires still). Also I have 6.12 mainline working good enough for NAS/server, that is actually most important.
Fallback is still some N100, but also with those boards, it is either no SATA or 4x SATA.

wooly wrote: ↑

Thu Nov 28, 2024 7:43 pm

Here getting one of such specific supplies cost 16,ドル that is not completely absurd [even if I have plenty of 3A ones, even a 5A one, that however is not PD compliant so it is refused]. the problem is that there are only three distributors, only by email order, and each one of them ask for a minimum order of 40€ or at least 6€ additional for shipping.
Se people is even more unhappy, since they feel exploited.
RPL should do one thing: offer to all orphan of the 5A PSU the opportunity to order one with free delivery at a local pick-up point [that is another problem: normal delivery happens at random time dropping the package, and it is not infrequent that are stolen on the way, i normally order only with suppliers that offer this service, so I am limited to Amazon and temu only)].
this would make people happy and they gain for trust.

Sounds to me like you should take all of that up with the resellers in your country. And your postal/delivery services.

RPL don't sell direct to the public (except through their shop in Cambridge) and if they did you'd probably end up paying more for shipping from the UK.

I'd expect the costs of free delivery outside the UK on a PSU to be more than you expect. Especially with the required customs paperwork (it's apparently pretty much the same whether one unit or a thousand are in the box) and charges. Even if the recipient paid the import duty it's likely they'd make a loss on every unit.

The UK isn't in the EU anymore, remember.

As for not being able to use 3A or non PD 5A supplies. That's untrue. You can override the PD behaviour and force the firmware to assume a 5A capable supply. I've actually booted and run a Pi5 (from NVMe) on the 1.6A output from another Pi5's USB port. Sure, there were a few low voltage warning but it was stable under light load.

Knowledge, skills, & experience have value. If you expect to profit from someone's you should expect to pay for them.

All advice given is based on my experience. it worked for me, it may not work for you.
Need help? https://github.com/thagrol/Guides

That power supply "problem" has been the normal one with each evoluttion of RPi, no only changing the USB type of connector but requiring more current that the previous one, but it is fully justified if we want RPi to keep on evolving and improving. Let's see if the USB C type is the final one for the future RPIs (I bet that they will change again :-)
I had the RPi 2, 3, 3B+, 4 , and now RPI 5 with 8GB. No need to say that RPI5 shocked me with its quick power up and power down times, as well as its fast response with aplications like Libreoffice and other heavy ones.
On the other side of the balance, its introduction was not fully aligned with his required libraries (mainly external) and took some time to catchup (i.e.: vnc) . Several of my previous python programs don ́t work with RPI5's operating system and previous libraries , therefore I am having some fun dealing with the required changes.

thagrol wrote: ↑

Fri Nov 29, 2024 11:40 am

RPL don't sell direct to the public (except through their shop in Cambridge) and if they did you'd probably end up paying more for shipping from the UK.

It can be surprisingly affordable, depending on where you are shipping to. I am in Canada and have ordered about half my Pi stuff from UK based resellers.

bjtheone wrote: ↑

Fri Nov 29, 2024 3:32 pm

thagrol wrote: ↑

Fri Nov 29, 2024 11:40 am

RPL don't sell direct to the public (except through their shop in Cambridge) and if they did you'd probably end up paying more for shipping from the UK.

It can be surprisingly affordable, depending on where you are shipping to. I am in Canada and have ordered about half my Pi stuff from UK based resellers.

No doubt. But the definition of affordable varies with the person. All we know about the person I was responding to is that they're somewhere in the euro zone (by extension the EU)and probably not a native English speaker. Sending stuff to the EU used to be easy. Then a bunch of right wing idiots mage it more difficult and caused more taxation on it.

Sorry. Got political for a moment there. That's definitely too off topic.

Knowledge, skills, & experience have value. If you expect to profit from someone's you should expect to pay for them.

All advice given is based on my experience. it worked for me, it may not work for you.
Need help? https://github.com/thagrol/Guides

jmontsecal wrote: ↑

Fri Nov 29, 2024 3:31 pm

That power supply "problem" has been the normal one with each evoluttion of RPi, no only changing the USB type of connector but requiring more current that the previous one, but it is fully justified if we want RPi to keep on evolving and improving. Let's see if the USB C type is the final one for the future RPIs (I bet that they will change again :-)
I had the RPi 2, 3, 3B+, 4 , and now RPI 5 with 8GB. No need to say that RPI5 shocked me with its quick power up and power down times, as well as its fast response with aplications like Libreoffice and other heavy ones.
On the other side of the balance, its introduction was not fully aligned with his required libraries (mainly external) and took some time to catchup (i.e.: vnc) . Several of my previous python programs don ́t work with RPI5's operating system and previous libraries , therefore I am having some fun dealing with the required changes.

The changes are too fast for me. My experience with ATX power supplies is, as long as one is not building the ultimate gaming machine, that the same supply works in PCs that span a time period of about 30 years. Even so, the weird 12VHPWR in the ATX 3.1 revision has me wondering. It seems standards are more used to ensure obsolescence these days rather than compatibility.

Last edited by ejolson on Fri Nov 29, 2024 5:34 pm, edited 1 time in total.

wooly wrote: ↑

Thu Nov 28, 2024 7:43 pm

I have plenty of 3A ones, even a 5A one, that however is not PD compliant so it is refused.

No.

Not 'refused.'


"Not recognised by the (non-existent) PD negotiation as being capable of delivering 5 amps" would be a more accurate statement.

Except under very demanding usage an RPi5 can run perfectly well from a 3 amp supply.

Beware of the Leopard

B.Goode wrote: ↑

Fri Nov 29, 2024 4:40 pm

wooly wrote: ↑

Thu Nov 28, 2024 7:43 pm

I have plenty of 3A ones, even a 5A one, that however is not PD compliant so it is refused.

No.

Not 'refused.'


"Not recognised by the (non-existent) PD negotiation as being capable of delivering 5 amps" would be a more accurate statement.

Except under very demanding usage an RPi5 can run perfectly well from a 3 amp supply.

Here demanding means connecting any storage device to USB or a PCIe m.2 hat.

ejolson wrote: ↑

Fri Nov 29, 2024 4:43 pm

B.Goode wrote: ↑

Fri Nov 29, 2024 4:40 pm

wooly wrote: ↑

Thu Nov 28, 2024 7:43 pm

I have plenty of 3A ones, even a 5A one, that however is not PD compliant so it is refused.

No.

Not 'refused.'


"Not recognised by the (non-existent) PD negotiation as being capable of delivering 5 amps" would be a more accurate statement.

Except under very demanding usage an RPi5 can run perfectly well from a 3 amp supply.

Here demanding means connecting any storage device to USB or a PCIe m.2 hat.

Has the boot loader changed recently then? I though the confirm on boot was only needed if the USB device is the boot device. Even money chance I'm wrong about that though as I've not tested it.

Knowledge, skills, & experience have value. If you expect to profit from someone's you should expect to pay for them.

All advice given is based on my experience. it worked for me, it may not work for you.
Need help? https://github.com/thagrol/Guides

thagrol wrote: ↑

Fri Nov 29, 2024 5:10 pm

ejolson wrote: ↑

Fri Nov 29, 2024 4:43 pm

B.Goode wrote: ↑

Fri Nov 29, 2024 4:40 pm

Except under very demanding usage an RPi5 can run perfectly well from a 3 amp supply.

Here demanding means connecting any storage device to USB or a PCIe m.2 hat.

Has the boot loader changed recently then? I though the confirm on boot was only needed if the USB device is the boot device. Even money chance I'm wrong about that though as I've not tested it.

It might be possible to override the power limits on the USB ports and pretend one has a 5A supply even when it's not and then successfully mount an external drive. Even if it works at first, the SSD could draw more power over time as it wear levels while the under-specified power supply may age and fail at the wrong end of the bathtub.

thagrol wrote: ↑

Fri Nov 29, 2024 5:10 pm

ejolson wrote: ↑

Fri Nov 29, 2024 4:43 pm

B.Goode wrote: ↑

Fri Nov 29, 2024 4:40 pm

No.

Not 'refused.'


"Not recognised by the (non-existent) PD negotiation as being capable of delivering 5 amps" would be a more accurate statement.

Except under very demanding usage an RPi5 can run perfectly well from a 3 amp supply.

Here demanding means connecting any storage device to USB or a PCIe m.2 hat.

Has the boot loader changed recently then? I though the confirm on boot was only needed if the USB device is the boot device. Even money chance I'm wrong about that though as I've not tested it.

This is specific to USB boot on Pi5 because the bootloader is just deciding whether whether to select the high or the low current for USB power. For CM5 there is no boot time check because the design use-case for an embedded system where the designer has considered the power requirements. However, it's still possible to query the USB-PD information (if relevant) from device-tree 'chosen' to support customer UIs / power decisions from the OS.

ejolson wrote: ↑

Fri Nov 29, 2024 4:43 pm

Not 'refused.'
"Not recognised by the (non-existent) PD negotiation as being capable of delivering 5 amps" would be a more accurate statement.

Except under very demanding usage an RPi5 can run perfectly well from a 3 amp supply.

Here demanding means connecting any storage device to USB or a PCIe m.2 hat.

1. it start and shut down before even activating the monitor so i call it "refusing"
2. some friends having RPI5 told that were happy with a 3A PSU they previously used on a Pi4, so i trusted them.
3. with a PD compliant 3A it works, but has problems with PCIe m.2 expansion [not hat since is not connected to GPIO] when an high rate of I/O is made.
The producer of the board when I asked how to connect to the extra 2 pins for a 5V supply replied that for memories less than 1TB the supply from the PCIe cable is enough, and this was confirmed even here, telling that since the PCIe on RPI5 uses only one lane the power requirement of the "official" ssd tagged as 2.4A were acceptable.
Also the boot did not complain when booting from nvme with 3A .
It looks that it was not marked enough strong in the various documentation that the limits on power supply does apply not only to USB boot, but also to nvme boot [or using heavily the nvme after boot]
For this I was unhappy.
4. someone here said that I should have complained to the courier or the supplier: if i order from the local distributor I would pay 13,25€ for the PSU and 9€ for shipping (and if courier do not find me at home I have to go to collect 20 km away) or i have to collect at their shop ... 340 km away from here. My usual supplier for these devices ship for free click and collect but only for orders over 40€ [and it sell for 16€]
5. what happen if i connect the second exit from my PSU [that has 3 3A capable exits, up to 40W total] to some 5V point [which is better?] in the RPi5 or the M2 adapter? will the on-off switch continue to work?

--
Leonardo
mailto:[email protected]

It I documented that the Pi4 PSU is fine, but will limit everything to the 0.6A so don't connect anything that needs more.
It is documented (maybe just mentioned) that that is the 5V lines, it includes the fan connector for example.
If you are trying to run something that needs more than that, be it an SSD os an up to 2.5A NVME common sense would say 0.6A is not enough.
It is mentions that thing may boot but if the CPU needs that 'current' things may suddenly stop.

At boot often lots of devices drawer full power, hence stuff don't work.

Hence it is recommended to use Thier purpose buil PSU for the Pi5, just like I would need to buy an expensive charger to charge my Phone at full speed, and why I had to buy my son a 750W PSU for his computer and not a standard 300 to 450 PSU I already had.

bensimmo wrote: ↑

Sat Nov 30, 2024 6:07 pm

It I documented that the Pi4 PSU is fine, but will limit everything to the 0.6A so don't connect anything that needs more.
It is documented (maybe just mentioned) that that is the 5V lines, it includes the fan connector for example.

what i have alwais read [maybe otherwise is really hidden] is that it limits 0,6A to the USB ports, so i did not worried about it since all that I connect there never draw more than 45 mA [even keyboard and mouse do not draw anything since are BT]

If you are trying to run something that needs more than that, be it an SSD os an up to 2.5A NVME common sense would say 0.6A is not enough.
It is mentions that thing may boot but if the CPU needs that 'current' things may suddenly stop.
At boot often lots of devices drawer full power, hence stuff don't work.

Incidentally it did not shut when booting, but only when X was started and you tried to open something.
What i complain is that was always written in the documentation available when i bought the RPi5 that a 3A PSU would have limited only the USB part. It was never clearly written that also nvme memory could have been affected ! (and specs for that say that with 500G is 0.5 to 0.7 A, so since the PCIe port is integrated on the RPi i assumed it was included on the 2.4 "base")

just like I would need to buy an expensive charger to charge my Phone at full speed, and why I had to buy my son a 750W PSU for his computer and not a standard 300 to 450 PSU I already had.

Your examples stay on my side: you buy a new charger to charge the phone at high speed, but this is specified in the characteristics of the phone, if you do not need fast charge you may use a standard one, is not that phone suddenly reset if you look a movie. For the computer probably you had a clear specification telling that the MB draws a certain current and the same for each peripheral so you decided for a bigger PSU.

So, in short, i should assume that the current draw from the SSD on the PCIe interface, even if not drawn from the USB or the GPIO counts toward the 0,6 A limit for USB so the 13W that normally the RPi5 uses do not include device on the PCIe port [and probably not even cameras on CSI ....]?

--
Leonardo
mailto:[email protected]

Nope the computer (PC) would stop and not work with the lower spec PSU in the computer, so a new one had to be bought.
Also with the PC before that it wouldn't boot with the old GPU card due to not enough power so even then a new PSU had to be bought, with a few extra connectors iirc.


But I do get you point about USB and that may depend how you read the release information
https://www.raspberrypi.com/news/introd ... erry-pi-5/
It does say that the peak CPU power draw is 2.4A. Also the HAT's and NVME was not out or announced, unfortunately they can't magic current if the CPU happens to wanting do draw that 2.4A

For users who wish to drive high-power peripherals like hard drives and SSDs while retaining margin for peak workloads, we are offering a 12ドル USB-C power adapter which supports a 5V, 5A (25W) operating mode. If the Raspberry Pi 5 firmware detects this supply, it increases the USB current limit to 1.6A, providing 5W of extra power for downstream USB devices and 5W of extra on-board power budget: a boon for those of you who want to experiment with overclocking your Raspberry Pi 5

I hope the documentation writers can check it is clear (now HAT and NVME/AI etc use is available)
though I just looked and the second FAQ for PI5 hardware page and the FAQ
https://www.raspberrypi.com/products/raspberry-pi-5/
does not specify USB at all.

Will my Raspberry Pi 4 power supply work with Raspberry Pi 5?
Raspberry Pi 5 is a higher-performance computer than Raspberry Pi 4, and you may have problems using an under-powered supply. We recommend a high-quality 5V 5A USB-C power supply, such as the new Raspberry Pi 27W USB-C Power Supply.

bensimmo wrote: ↑

Sat Nov 30, 2024 7:24 pm

(...)

For users who wish to drive high-power peripherals like hard drives and SSDs while retaining margin for peak workloads, we are offering a 12ドル USB-C power adapter which supports a 5V, 5A (25W) operating mode. If the Raspberry Pi 5 firmware detects this supply, it increases the USB current limit to 1.6A, providing 5W of extra power for downstream USB devices and 5W of extra on-board power budget: a boon for those of you who want to experiment with overclocking your Raspberry Pi 5

I understand[understood] that the two extra A were half to power USB devices and half to allow to overclock. So I assumed that the current draw on the PCIe interface had already taken in account...

Also a BIG question: why when current go high instead of an abrupt shut down [without even syncing data] the RPi5 would not underclock to reduce power [it would be an interesting option to be able to have it always running at half clock, for applications that does not need always full speed]

About:

Will my Raspberry Pi 4 power supply work with Raspberry Pi 5?
Raspberry Pi 5 is a higher-performance computer than Raspberry Pi 4, and you may have problems using an under-powered supply. We recommend a high-quality 5V 5A USB-C power supply, such as the new Raspberry Pi 27W USB-C Power Supply.

We say here: "non chiedere all'oste se il suo vino è buono" (trad.: "never ask to an inkeeper if its wine is good") so, this part, I just saw it as a plain advertisement.

--
Leonardo
mailto:[email protected]

But it's not just an advert, they didn't make the new PSU for fun (well they my have had fun, someone might, who knows).

There are now other 5V5A Pi5 ready PSUs, there wasn't at release, so it means you can by other manufacturers. There's is designed to just work*.
Or bring your own 5V5A and make you own and run it through the GPIO or similar, maybe a PoE or other solution. They gave a way to make them work easier without it asking all the time at bootm

(note: some didn't just work at launch, not seen any reports about that again though, you had to turn them off and on again, no idea why)


As for crashing? Other Pi models reduce/limit speed, I know the Pi3 crawls in that mode, but that's on a voltage drop. If the current ramps up the voltage may just drop too far too quickly or the PSU shuts down too.

Other may be able to tell you what really happens.