Subj : Re: Stress testing a Pi...
To   : Pancho
From : The Natural Philosopher
Date : Sun May 12 2024 01:57:25

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"

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