Danoposada
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Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Wed Aug 21, 2019 4:01 am

Hello everyone. I'm Daniel and a RPi 4 will be arriving at my door in a week or three. First timer 8-)
I want to take the RPi 4, attach a 2.5" HDD, build a case for the whole thing, and attach a couple of wired gamepads for gaming with my fiancee. I'm hoping the case doesn't have to be too bulky.
(A bit of a heads up: I know NOTHING about electricity, so I apologize in advance if this questions seem dumb)

So, I've been reading a bit about connecting a 2.5 HDD via USB 3.0 and one of the first issues mentioned is how the RPi4 can't reliably power a HDD on it's own. Now, why is that?
Is it because:
1) The official power supply can't handle the load?
2) the USB 3.0 standard can't handle the load?
3) Both?
4) None of the above?

See, I've been shuffling some solutions for each problem but, since I don't know what I'm doing, I don't know what is feasible.

Here's what I'm thinking:

Solution to 1) Get a better power supply.
If this is the fix, can anyone point me in the right direction? what specs am I looking for?

Solution to 2.A) Use a Y-shape USB cable and sacrifice one of the other USB ports in favor of more power for the HDD.

Solution to 2.B) Get either a powered SATA-to-USB 3.0 adapter or a powered hub.
This solution is not attractive to me because it's "bulky": I'll have 2 power supplies attached to the wall at all times instead of one, and with the hub I'll have either and additional piece of hardware floating around , or a much bigger case (to hide the hub).

Solution to 3) Take either a Y-shape USB cable or a powered SATA-to-USB 3.0 adapter and find a common power supply for both the RPI 4 and the HDD. With this option, instead of using the PI's original power supply, I would attach both the Pi and the HDD to something like this:
https://lygte-info.dk/review/USBpower%2 ... %20UK.html

I tried to find something with specs akin to what (in my VERY limited knowledge of electricity) the RPi4 + HDD combo might need.

Problem 4) ?????

Sorry for making this so long.
Any help or insight is highly appreciated.
Cheers.

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rpdom
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Re: Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Wed Aug 21, 2019 5:17 am

Whether a Pi 4B can power a USB HDD depends on the drive and how much power it requires to start up. Most drives should be fine.

Using a Y cable plugged in to two of the USB ports on a Pi is pointless as all ports share a common 5V supply. You can pull up to 1.2A from any combination of the four USB ports. 1.2A from one port only, 0.3A from each of the four ports, 0.6A from 2 ports, 0.3A from one port and 0.9A from another, or any combination that adds up to 1.2A.

Apart from very large storage, I'm switching to SSDs on my Pis that required more than a few GB of storage. They use less current than HDDs and don't have a huge start-up surge requirement. Also the prices are dropping nicely.

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Gavinmc42
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Re: Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Wed Aug 21, 2019 7:22 am

Did you get the official 3Amp Power supply too?
They increased the Pi's current capability so USB drives are more reliable.
SSD draw less power so would be a better choice.

But I got an externally powered dock as well, so I can swap drives around.
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Danoposada
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Re: Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Wed Aug 21, 2019 6:06 pm

Ok, seems like the RPi4 can support a 2'5" HDD, but ¿will it be able to support The HDD with the other peripherals at the same time?
Like, if I have A 2.5" HDD + 2 wired gamepads + keyboard + mouse; will it run reliably?
I mean, all external USB 3.0 HDDs can draw up to 0.9A (at least, that's the limit they work with)
So, are those 0.3A that are left over enough to power the other peripherals and stay stable?
Last edited by Danoposada on Wed Aug 21, 2019 9:13 pm, edited 1 time in total.

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HawaiianPi
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Re: Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Wed Aug 21, 2019 7:34 pm

Danoposada wrote:
Wed Aug 21, 2019 6:06 pm
Ok, seems like the RPi4 can support a 2'5" HDD, but ¿will it be able to support The HDD with other peripherals)?
No one here can answer that without knowing the exact spec's of your equipment. Add up the power requirements of everything you want to connect, and if it's less than 1.2A you should be fine.

As others have suggested, use an SSD instead, for improved performance and lower power consumption.

Or get an externally powered HDD, HDD dock, or USB hub.

I've used my Pi computers with HDD up to 2TB, and most work fine with no additional power. The exception would be internal drives mounted in enclosures, which may not conform to the USB power spec (typically 7200 RPM drives, but I've seen slower drives with 1A+ power ratings). Most 2.5" portable USB drives should work fine as storage. Booting from USB is not supported on the Pi4 at this time, but will be added in a future firmware update (it is possible to have /boot on SD card and / on USB).
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bjtheone
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Re: Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Wed Aug 21, 2019 8:31 pm

Beyond being less power hungry than a real hard drive, an SSD is also smaller, easier to package, and much more robust.

If you go with a wireless keyboard/mouse combo or a media keyboard with a builtin track pad you have enough USB ports and life should be grand. If you want to go all wired you end up short a USB port and need to add a HUB into the mix. At that point you can go powered HUB and solve your power issues (if any) that way.

I have no idea what a gamepad draws but I have a 4B with a 128 Gb SSD, 2 wireless receivers, USB3 thumb drive, cat5 ethernet, 1 HDMI connected monitor, and a set of powered external speakers running happily off of the official P/S.

Danoposada
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Re: Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Wed Aug 21, 2019 9:17 pm

Ok. I'll keep all these in mind.
Thanks for all the insight, really. ^_^

Cheers.

Danoposada
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Re: Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Thu Aug 22, 2019 6:24 pm

Ok, this is my last goose-chase on the subject, I promise :oops:
Keep in mind that all this nonsense is so I can use only one power supply instead of 2, as I'm aware that all this could be easily worked out with a powered USB hub and 2 power supplies.

So I've been absorbing all this info, and trying to figure out what all this means. This is what I THINK the info I've gathered means (keep in mind I don't really know much about electricity):
Taking my maximum hypothetical setup (RPi4 + USB 3.0 HDD + 2 wired gamepads + wireless dongle for keyboard and mouse) the hypothetical max and average power draw would be something like this:

ITEM/MAX AMP/AVG AMP/INFO SOURCE/
RPi 4/ /1.25/ /0.6 - 0.85/ /SOURCE
USB 3.0 HDD/ /0.9 [USB 3.0]/ /0.5/ /SOURCE/
Wired gamepad (x2)/ /0.5 (1.0)/ /???/ /SOURCE/
Keyboard/mouse dongle/ /0.5 [USB 2.0]/ /???/ /N/A

From what I gather, the problem with peripherals is NOT that the official power supply (or any other, for that matter) can't handle load, as forgoing the use of keyboard/mouse with gamepads at the same time (I.e: using either dongle or gamepads, not both at the same time) and using either gamepads with low amp or a PSX dual adapter (which I already have at hand and is incredibly cheap) would put me in a hypothetical max power draw of 2.6 amps (including the RPi 4).
Well below the 3.0 amps that the official power supply provides.
(As a side note: the canakit power supply works at 5.1V / 3.5A. Are they any any good?)

The real problem is that the USB ports can only draw 1.2A max - A USB 3.0 HDD + PSX dual adapter draws a max of 1.4A.
Now, max and real power draws are different, so that setup MIGHT work, but is not guaranteed.

To guarantee it I need a way to give power to at least one of the peripherals directly from the power supply; preferably the HDD.

Now, here's the question: is there an adapter or something that might allow me that?

EDIT: Would something like this work?
The idea is to connect the official power supply to this hub, then the hub to the RPi4, then use one of these cables to connect the HDD to both the RPi 4 and the HUB: USB 3.0 to the Pi for data and USB 2.0 to the HUB for power

Fraoch
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Re: Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Fri Aug 23, 2019 2:37 pm

Danoposada wrote:EDIT: Would something like this work?
The idea is to connect the official power supply to this hub, then the hub to the RPi4, then use one of these cables to connect the HDD to both the RPi 4 and the HUB: USB 3.0 to the Pi for data and USB 2.0 to the HUB for power
I'm not sure how the Y-cable would behave - ideally it would feed power via USB 2.0 and data through USB 3.0 but it might not work like that, instead sharing the power, drawing whatever it could over USB 3.0 and whatever it could over USB 2.0 and backfeeding as well.

It might be better to get a powered USB hub that does not backfeed.

However, another idea: Bluetooth devices free up ports and free up power requirements. Do you already have your keyboard, mouse and game pad? Because if you don't, look at Bluetooth devices. There are lots of nice Bluetooth keyboards, I recently got a cheap Bluetooth mouse that works very well, and there are some very nice Bluetooth gamepads that work well with Linux, like:

https://www.amazon.com/8Bitdo-SN30-Cont ... way&sr=8-3

Those will free up enough power that you'll easily have the power for the USB HDD...though if you don't have this already you may want to switch to an SSD for power savings and extra speed.
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Danoposada
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Re: Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Fri Aug 23, 2019 8:19 pm

Fraoch wrote:
Fri Aug 23, 2019 2:37 pm
Do you already have your keyboard, mouse and game pad?
Fraoch wrote:
Fri Aug 23, 2019 2:37 pm
though if you don't have this already you may want to switch to an SSD for power savings and extra speed.
Big part of the problem boils down to that.

First, I already have all of that: Wireless dongle for keyboard and mouse, 2 original Dualshock 2 gamepads, PSX to USB dual adapter, a Toshiba USB 3.0 HDD; plus an original Dualshock 3.

Second, even if that weren't the case, there are the problems of availability and cost.
I don't live in the USA, I don't live in the Euro zone. Currency conversion and cost of living make a huge difference: If it's easily available locally or it can be considered at least a bit "legacy" stock, is cheap; and by that, it means it has a price in line with what everything costs around here. If not, is overpriced as hell.

USB 3.0 HDDs, original Dualshock 2 and 3, PSX adapters are very affordable and easly available; SSDs and products like the 8Bitdo aren't.

I mean with the money I buy two Dualshock 2, two Dualshock 3 AND the PSX dual adapter (5 items total), I'd still be $4.99 short for buying just that ONE 8Bitdo gamepad (plus around $13 in shipping, if I can't manage to find it locally)
HDDs vs. SSDs are the same tale: External USB 3.0 HDDs are about 35% cheaper than internal SSDs; external SSDs are even a bit more expensive.

A HUB like the one I asked about and the Y cable are around $10 each.

And of course, there's the aesthetic component:
Danoposada wrote: Keep in mind that all this nonsense is so I can use only one power supply instead of 2, as I'm aware that all this could be easily worked out with a powered USB hub and 2 power supplies

Danoposada
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Re: Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Sat Aug 24, 2019 3:08 am

Fraoch wrote:
Fri Aug 23, 2019 2:37 pm

I'm not sure how the Y-cable would behave - ideally it would feed power via USB 2.0 and data through USB 3.0 but it might not work like that, instead sharing the power, drawing whatever it could over USB 3.0 and whatever it could over USB 2.0 and backfeeding as well.
Ok, forget the Y cable.
How about this:
This kind of hub : connect the official power supply to the hub, and the hub to the Pi's power port. Power done.
Then, for data, connect the HDD to the hub, and use a male-to-male USB 3.0 cable to connect one of the hub's USB ports to one on the Pi.


Would that work?
What problems does that setup have?

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Re: Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Sat Aug 24, 2019 6:30 am

Danoposada wrote:
Sat Aug 24, 2019 3:08 am
Fraoch wrote:
Fri Aug 23, 2019 2:37 pm

I'm not sure how the Y-cable would behave - ideally it would feed power via USB 2.0 and data through USB 3.0 but it might not work like that, instead sharing the power, drawing whatever it could over USB 3.0 and whatever it could over USB 2.0 and backfeeding as well.
Ok, forget the Y cable.
How about this:
This kind of hub : connect the official power supply to the hub, and the hub to the Pi's power port. Power done.
Then, for data, connect the HDD to the hub, and use a male-to-male USB 3.0 cable to connect one of the hub's USB ports to one on the Pi.


Would that work?
What problems does that setup have?

The Raspberry Pi SBC requires a Power Supply and not a Charger, which is what you have linked to.......
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Danoposada
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Re: Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Sat Aug 24, 2019 3:45 pm

fruitoftheloom wrote:
Sat Aug 24, 2019 6:30 am
The Raspberry Pi SBC requires a Power Supply and not a Charger, which is what you have linked
1) It ISN'T a charger, It's a HUB. I don't mean to be rude, but maybe you didn't take the time to actually look at the product:
Product Page wrote: i-tec USB-C HUB 3 Port + Power Delivery
2) It WOULD use a power supply: the OFFICIAL RPi 4 power supply.
(Or the one from Canakit, if someone can confirm they are good. It's 5.1V / 3.5A - a bit higher than the official one)
That's the reason I looked into that hub:
Product Page wrote: USB Type-C Power Delivery port for charging notebooks, tablets or smartphones with support for Power Delivery. To this port you can connect an original or a universal AC power adapter with USB Type-C connector.
3) Even if it wouldn't work, an explanation as to why would be usefu,l so one doesn't repeat the same mistakes over and over.
This might come as a surprise to some, but most of us come here to learn, and not just for a quick and easy answer.
I have learned more about electricity in this past 5 days than in all my 35 years.
Last edited by Danoposada on Sat Aug 24, 2019 4:14 pm, edited 1 time in total.

fruitoftheloom
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Re: Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Sat Aug 24, 2019 4:11 pm

Danoposada wrote:
Sat Aug 24, 2019 3:45 pm
fruitoftheloom wrote:
Sat Aug 24, 2019 6:30 am
The Raspberry Pi SBC requires a Power Supply and not a Charger, which is what you have linked
1) It ISN'T a charger, It's a HUB. I don't mean to be rude, but maybe you didn't take the time to actually look at the product:
Product Page wrote: i-tec USB-C HUB 3 Port + Power Delivery
2) It WOULD use a power supply: the OFFICIAL RPi 4 power supply.
(Or the one from Canakit, if someone can confirm they are good. It's 5.1V / 3.5A - a bit higher than the official one)
That's the reason I looked into that hub:
Product Page wrote: USB Type-C Power Delivery port for charging notebooks, tablets or smartphones with support for Power Delivery. To this port you can connect an original or a universal AC power adapter with USB Type-C connector.
3) Even if it wouldn't work, an explanation as to why would be useful so one doesn't repeat the same mistakes over and over.
This might come as a surprise to some, but most of us come here to learn, and not just for a quick and easy answer.
I have learned more about electricity in this past 5 days than in all my 35 years.

Charging a Laptop Battery or Smartphone Battery is not the same as powering a Raspberry Pi.

A good power supply has a stable voltage +/- 5%, whereas a charger can have great variance depending on what it is designed to charge
:roll:

Power Delivery port for charging notebooks, tablets or smartphones with support for Power Delivery.

https://www.goalzero.com/blog/what-tech ... -delivery/
Last edited by fruitoftheloom on Sat Aug 24, 2019 4:34 pm, edited 3 times in total.
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Danoposada
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Re: Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Sat Aug 24, 2019 4:18 pm

How is it that a power delivery port doesn't deliver power?

What's the difference?

Fraoch
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Re: Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Mon Aug 26, 2019 2:12 pm

Danoposada wrote:
Fri Aug 23, 2019 8:19 pm
First, I already have all of that: Wireless dongle for keyboard and mouse, 2 original Dualshock 2 gamepads, PSX to USB dual adapter, a Toshiba USB 3.0 HDD; plus an original Dualshock 3.
Thought so and that's why I asked...oh well.
Second, even if that weren't the case, there are the problems of availability and cost.
I don't live in the USA, I don't live in the Euro zone. Currency conversion and cost of living make a huge difference: If it's easily available locally or it can be considered at least a bit "legacy" stock, is cheap; and by that, it means it has a price in line with what everything costs around here. If not, is overpriced as hell.

USB 3.0 HDDs, original Dualshock 2 and 3, PSX adapters are very affordable and easly available; SSDs and products like the 8Bitdo aren't.

I mean with the money I buy two Dualshock 2, two Dualshock 3 AND the PSX dual adapter (5 items total), I'd still be $4.99 short for buying just that ONE 8Bitdo gamepad (plus around $13 in shipping, if I can't manage to find it locally)
HDDs vs. SSDs are the same tale: External USB 3.0 HDDs are about 35% cheaper than internal SSDs; external SSDs are even a bit more expensive.

A HUB like the one I asked about and the Y cable are around $10 each.
I hear you, I'm in Canada and things here are exchange rate + up to 50% premium if they're available at all.
Danoposada wrote: How is it that a power delivery port doesn't deliver power?

What's the difference?
What's meant by that is the port complies with the USB Power Delivery standard. Simply put, there's a two-way communication with the connected device - if the connected device reports the capability, USB PD delivers up to 100 W at higher voltages and currents (maximum 20 V @ 5 A = 100 W). If the device does not report back that it is USB-PD capable, the charger assumes it's a "dumb" device and supplies the standard 5 V at up to 3 A.

The Rasbperry Pi 4 is such a device. It is not USB-PD capable and so does not report back anything. Any charger or power supply then delivers 5 V. The official Raspberry Pi power supply has been built to actually provide 3 A at 5 V. Inferior power supplies or chargers may allow the voltage to sag when delivering that much current - it can sag low enough that the Raspberry Pi may not boot or may exhibit problems, problems with its connected devices or SD card corruption. A charger will still work if it delivers, say 4.7 V at 3 A, but a Raspberry Pi cannot be powered by such a charger.

Those chargers may have inferior voltage conversion sections (undersized because they're cheap or use inferior components that can't deliver the power required and maintain 5 V) or thin wires with too much resistance.

The Raspberry Pi power supply is designed to actually deliver 5 V @ 3 A and not sag. In fact, it outputs 5.1 V to compensate for any losses.

Personally I wouldn't "route" the Raspberry Pi's power supply through the hub, the Raspberry Pi power supply should go directly to the Rasbperry Pi and nowhere else. Get a powered hub that does not backfeed and use its own, separate, power supply.

There are recommendations here:

https://elinux.org/RPi_Powered_USB_Hubs

which are unfortunately from the RPi3B+ days so there are not many USB 3.0 hubs.

I see the one at the top of the list, unfortunately it's quite expensive:

https://www.amazon.ca/Anker-Charging-Ad ... =pc&sr=1-3

Another hub on the list seems only to be available in the Euro zone but is also quite expensive:

https://www.amazon.de/IB-AC611-4-fach-U ... B00CO3RAA4

This one is a slightly more reasonable price and seems to be available in Europe:

https://www.amazon.fr/Transcend-TS-HUB3 ... B005D69QD8

Keep looking and post back here.
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313Alf
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Re: Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Mon Aug 26, 2019 8:48 pm

Thanks for this post, I think it may explain why my Pi4 setup kept freezing when running SDR software.
Peripherals used were Intel SSD (1A), RTL-SDR dongle (~0.24A) and official keyboard/mouse (~0.08A). Definitely over the 1.2A limit. I use the official Pi4 power supply.

I went back to SD card only and it now works fine for SDR. I should have been using an externally powered USB hub for my initial setup. I'll check out the ones mentioned in above replies.

Danoposada
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Re: Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Thu Aug 29, 2019 10:58 pm

@Fraoch:

That's amazing. It's a very complete answer :) .

Thanks a million, it really did clarify a lot of questions I had.

I guess y I'll keep looking for a way to do this, or a powered USB.

I'm not sure how much luck I'll have with that.
I went to the biggest tecnology mall in the city and found only 2 powered hubs: one was 2.0 and the other was 3.0. Worst, neither was listed in the page you linked.
Still, I'll keep looking.

And Fraoch, again, thank you for the answer. You are the best.

Fraoch
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Re: Powering a RPI 4 + 2.5" HDD connected to USB 3.0

Thu Aug 29, 2019 11:07 pm

You're very welcome! :)

Personally, I would not buy this in a "bricks & mortar" physical shop. It's nice to support them, but if you're saying that one of the largest ones only had two USB hubs in total then you've got to look online.

Amazon's eliminating competitors like that - which is a shame but with a result like that you can see why.

Do you have access to Amazon where you are? That's where I'd get it if I were you. There may be other online shops worth checking out as well - not being from Europe I would not have any idea what to recommend.
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