Well it was always going to be a shot in the dark...:-)

And I think I can confirm that a Pi4 cannot drive three SSDs over USB
unaided.
As soon as I tried to rsync a new drive as a backup, via NFS, I started
to get disk errors. On unrelated disks...not involved in the transfer.

The PI4 had a TV card on it that gets pretty hot so I removed that to
reduce load on the power supply, but significantly it made *no
difference at all*.

I hooked up a n HDMI screen to monitor the console messages and it was
full of disk errors of one sort or another.

Not necessarily related to the drive in use.

My tentative conclusion, which I would like some opinion on, is that it
is the USB power limit that is causing the problems, not the overall
power draw. As that would have bee relieved by removing the TV hat.

Now as far as I can tell the total USB power available on the PI4
equates to 1200mA.

But on the Pi 5 that increase to 1600mA, provided you tell the board it
has a 'high power supply'.

I believe there is a config.txt option to do that. Even if you don't
have the 'approved' PSU.

So I am thinking of going to a PI 5 rather than a separately powered USB
adapters for the drives - the other way to increase power to the drives.

Or is there a better one board computer alternative?

I want to build everything into a small 19" case with an ethernet switch
board and OSUs to reduce clutter

--
Of what good are dead warriors? … Warriors are those who desire battle
more than peace. Those who seek battle despite peace. Those who thump
their spears on the ground and talk of honor. Those who leap high the
battle dance and dream of glory … The good of dead warriors, Mother, is
that they are dead.
Sheri S Tepper: The Awakeners.

The Natural Philosopher <tnp@invalid.invalid> wrote:
> So I am thinking of going to a PI 5 rather than a separately powered USB
> adapters for the drives - the other way to increase power to the drives.
>
> Or is there a better one board computer alternative?
>
> I want to build everything into a small 19" case with an ethernet switch
> board and OSUs to reduce clutter

If you want a Pi5 NAS, this looks like a good option:

https://www.youtube.com/watch?v=l30sADfDiM8

Key part is the Radxa PCIe to 5x SATA HAT:
https://arace.tech/products/radxa-penta-sata-hat-up-to-5x-sata-disks-hat-for-raspberry-pi-5

(For 3.5" drives, there are cables so you can mount them away from the
board. USB HDD often have a SATA connector inside if you remove the
case)

Theo

On 11/05/2024 14:54, Theo wrote:
> The Natural Philosopher <tnp@invalid.invalid> wrote:
>> So I am thinking of going to a PI 5 rather than a separately powered USB
>> adapters for the drives - the other way to increase power to the drives.
>>
>> Or is there a better one board computer alternative?
>>
>> I want to build everything into a small 19" case with an ethernet switch
>> board and OSUs to reduce clutter
>
> If you want a Pi5 NAS, this looks like a good option:
>
> https://www.youtube.com/watch?v=l30sADfDiM8
>
> Key part is the Radxa PCIe to 5x SATA HAT:
> https://arace.tech/products/radxa-penta-sata-hat-up-to-5x-sata-disks-hat-for-raspberry-pi-5
>
> (For 3.5" drives, there are cables so you can mount them away from the
> board. USB HDD often have a SATA connector inside if you remove the
> case)
>
That may be an option all right - it takes external 12V which I can
probably supply.
And there is one for a Pi 4...

--
It is the folly of too many to mistake the echo of a London coffee-house
for the voice of the kingdom.

Jonathan Swift

The Natural Philosopher <tnp@invalid.invalid> wrote:
> On 11/05/2024 14:54, Theo wrote:
> > The Natural Philosopher <tnp@invalid.invalid> wrote:
> >> So I am thinking of going to a PI 5 rather than a separately powered USB
> >> adapters for the drives - the other way to increase power to the drives.
> >>
> >> Or is there a better one board computer alternative?
> >>
> >> I want to build everything into a small 19" case with an ethernet switch
> >> board and OSUs to reduce clutter
> >
> > If you want a Pi5 NAS, this looks like a good option:
> >
> > https://www.youtube.com/watch?v=l30sADfDiM8
> >
> > Key part is the Radxa PCIe to 5x SATA HAT:
> > https://arace.tech/products/radxa-penta-sata-hat-up-to-5x-sata-disks-hat-for-raspberry-pi-5
> >
> > (For 3.5" drives, there are cables so you can mount them away from the
> > board. USB HDD often have a SATA connector inside if you remove the
> > case)
> >
> That may be an option all right - it takes external 12V which I can
> probably supply.
> And there is one for a Pi 4...

I think the Radxa Pi4 one was released just before all the supply chain
mayhem when nobody could buy Pi 4s - I think they discontinued it so I'm
not sure it's actually available right now. On the Pi 4 you have to use USB
rather than PCIe, unless using a Compute Module (when you lose USB3).

I'd expect PCIe to be more stable under load than USB. They use a JMB585
PCIe to SATA chip which isn't enterprise grade but seems to work well
enough. Since Pi5 doesn't lose USB3, you can get 2.5G networking via a $10
USB adapter, rather than Jeff's odd PCIe switch.

The Pi4 was just a bit compromised for this use case IMO, but it looks like
the Pi5 plus this HAT gets most things right.

Theo

On 11/05/2024 09:53, The Natural Philosopher wrote:
> Well it was always going to be a shot in the dark...:-)
>
> And I think I can confirm that a Pi4 cannot drive three SSDs over USB
> unaided.
> As soon as I tried to rsync a new drive as a backup, via NFS, I started
> to get disk errors. On unrelated disks...not involved in the transfer.
>
> The PI4 had a TV card on it that gets pretty hot so I removed that to
> reduce load on the power supply, but significantly it made *no
> difference at all*.
>
> I hooked up a n HDMI screen to monitor the console messages and it was
> full of disk errors of one sort or another.
>
> Not necessarily related to the drive in use.
>
> My tentative conclusion, which I would like some opinion on, is that it
> is the USB power limit that is causing the problems, not the overall
> power draw. As that would have bee relieved by removing the TV hat.
>
> Now as far as I can tell the total USB power available on the PI4
> equates to 1200mA.
>
> But on the Pi 5 that increase to 1600mA, provided you tell the board it
> has a 'high power supply'.
>

1600mA isn't that much more than 1200mA. There is quite a difference in
the power requirements of different SSDs. Kingston A400 drives have a
max wattage of about 1.5 watts. Some other SSD drives quote up to 5
watts. NVME drives even more.

So If I were you, I would want to understand the drives you have, know
their power consumption, before making a decision.

FWIW, I only have one USB SSD running off an unpowered cable. The
additional drives use a secondary power supply, but I use spinning HDDs
as well as SSDs, so I needed to.

Also, the Pi 5 is a great computer, so worth buying just for fun. You'll
find something to use it for.

Theo <theom+news@chiark.greenend.org.uk> wrote:
> The Natural Philosopher <tnp@invalid.invalid> wrote:
> > So I am thinking of going to a PI 5 rather than a separately powered USB
> > adapters for the drives - the other way to increase power to the drives.
> >
> > Or is there a better one board computer alternative?
> >
> > I want to build everything into a small 19" case with an ethernet switch
> > board and OSUs to reduce clutter
>
> If you want a Pi5 NAS, this looks like a good option:
>
> https://www.youtube.com/watch?v=l30sADfDiM8
>
I don't see a Pi as the ideal NAS. Yes, it can make one but there are
better solutions. A Pi has other, better, uses.

My NAS solution is something like a Fujitsu Esprimo Q556 or Q957,
power consumption is similar to a Pi 4 or Pi 5 and it comes in a case
that can accomodate an M2 drive and two 2.5" drives. The power supply
is in the case with it. ...and it's still pretty compact.

--
Chris Green
·

On 11/05/2024 17:22, Pancho wrote:
> On 11/05/2024 09:53, The Natural Philosopher wrote:
>> Well it was always going to be a shot in the dark...:-)
>>
>> And I think I can confirm that a Pi4 cannot drive three SSDs over USB
>> unaided.
>> As soon as I tried to rsync a new drive as a backup, via NFS, I
>> started to get disk errors. On unrelated disks...not involved in the
>> transfer.
>>
>> The PI4 had a TV card on it that gets pretty hot so I removed that to
>> reduce load on the power supply, but significantly it made *no
>> difference at all*.
>>
>> I hooked up a n HDMI screen to monitor the console messages and it was
>> full of disk errors of one sort or another.
>>
>> Not necessarily related to the drive in use.
>>
>> My tentative conclusion, which I would like some opinion on, is that
>> it is the USB power limit that is causing the problems, not the
>> overall power draw. As that would have bee relieved by removing the TV
>> hat.
>>
>> Now as far as I can tell the total USB power available on the PI4
>> equates to 1200mA.
>>
>> But on the Pi 5 that increase to 1600mA, provided you tell the board
>> it has a 'high power supply'.
>>
>
> 1600mA isn't that much more than 1200mA. There is quite a difference in
> the power requirements of different SSDs. Kingston A400 drives have a
> max wattage of about 1.5 watts. Some other SSD drives quote up to 5
> watts. NVME drives even more.
>
> So If I were you, I would want to understand the drives you have, know
> their power consumption, before making a decision.
>
I did quite a lot of research before picking the drives that I did

> FWIW, I only have one USB SSD running off an unpowered cable. The
> additional drives use a secondary power supply, but I use spinning HDDs
> as well as SSDs, so I needed to.
>
> Also, the Pi 5 is a great computer, so worth buying just for fun. You'll
> find something to use it for.
>
Indeed. That was my thought. I could use it as another media driver for
the now redundant TVs (redundant because I have watched and/or recorded
all the repeats of all the shows I missed when working for a living, and
wall to wall propaganda and adverts is all that is left ...) and stick
high definition audio on it to play my music

>

--
"It is an established fact to 97% confidence limits that left wing
conspirators see right wing conspiracies everywhere"

On 11/05/2024 17:57, Chris Green wrote:
> Fujitsu Esprimo Q556

Nice idea, but the plan is to reduce box count by integrating everything
into one case, and so I need a small footprint board level device like a Pi.

--
“Those who can make you believe absurdities, can make you commit
atrocities.”

― Voltaire, Questions sur les Miracles à M. Claparede, Professeur de
Théologie à Genève, par un Proposant: Ou Extrait de Diverses Lettres de
M. de Voltaire

The Natural Philosopher <tnp@invalid.invalid> wrote:
> On 11/05/2024 17:57, Chris Green wrote:
> > Fujitsu Esprimo Q556
>
> Nice idea, but the plan is to reduce box count by integrating everything
> into one case, and so I need a small footprint board level device like a Pi.
>
But that's what is so good about the Fujitsu Esprimo Q556, it does get
everything in one case. You need no external power supply and you
need no external disk drives. You can even get a CD/DVD reader in
there if you want. It's all in a box 18cm x 18cm x 6cm (approx).

--
Chris Green
·