d00mpie
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RP4(4gb) with M.2

Tue Jul 02, 2019 12:45 am

I was considering ordering a RPi4 4gb model. But it all hinges on If I can get any type of solid state storage to USB 3.0 as my bootable media. So say m.2 to usb 3.0. Is this possible in the current state of the RPi 4? As it is still quite new hardware. I see there is the adapters but I dont know if its supported in software and what not.

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HawaiianPi
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Re: RP4(4gb) with M.2

Tue Jul 02, 2019 2:33 am

It sort of works now, but not in the best way. USB boot is currently not supported on the Pi4, but is planned for a future firmware update.

For now you can boot the main OS from a USB drive by placing /boot on an SD card and / (the root filesystem) on the USB drive (and editing a file or two). When USB boot enabled firmware becomes available the SD card will not be necessary.

I have a couple of Pi3 models that boot from a SATA SSD with a USB adapter, so yes, it's possible (just not fully supported on the Pi4 yet).
Image

If you'd like to know more about starting boot from SD and loading the OS from USB, just ask.
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plugwash
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Re: RP4(4gb) with M.2

Tue Jul 02, 2019 4:52 am

Be aware that there are three types of M.2 SSDs.

SATA
PCIe AHCI (rare)
PCIe NVME

In general USB to m.2 adapters (unlike M.2 slots on PC/laptop motherboards) will only support one type. Most will be for SATA m.2 SSDs. Ones for NVME drives do exist, but at least from reputable vendors they tend to be relatively expensive.

USB to SATA adapters (whatever the form factor) are generally supported by the generic USB mass storage drivers and should work fine. I suspect the same will be true for USB to NVME adapters but I haven't seen any reports from anyone who has actually tried them.

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HawaiianPi
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Re: RP4(4gb) with M.2

Tue Jul 02, 2019 6:03 am

Good point from plugwash. The M.2 SSD system is a confusing mess to most consumers (even somewhat tech savvy ones). The different drive types and keying often results in people buying the wrong drive or enclosure, leaving them wondering why the drive won't fit, or why they aren't getting the advertised performance.

So what does all this mean for the new Raspberry Pi 4B with it's USB 3.0 ports?

SATA-III is rated for 6 Gbps transfer speed, and most SSD models can get pretty close to saturating that. USB 3.0 is rated for 5 Gbps, so a SATA SSD in a USB 3.0 enclosure will be slower than one on an internal SATA-III port. An NVME SSD is many times faster than a SATA SSD, and will also be more expensive, as will an NVMe USB enclosure, but will not be faster on a USB 3.0 port.

This is even more true on a Pi4, which has all 4 USB ports on a single PCIe lane with a shared 4 Gbps throughput (much faster than USB 2.0, but less than full USB 3.0 speed).

So, if you are going to get an SSD and a USB 3.0 enclosure, get the much cheaper SATA parts, because the faster PCIe AHCI or NVMe drives will not offer any perceived performance advantage for the extra money (and it will be a lot of extra money for NVMe).

I actually have a spare 256GB NVMe SSD kicking around, and I've been looking for an enclosure for it, but the cheapest I can find is just under $30, which is the same price as a new 256GB SATA SSD! So it will cost me as much as a new SSD just to put my old one in an enclosure. My GF bought an M.2 SATA SSD enclosure from Amazon for $3 a few months ago (10X less than an NVMe enclosure).

If you don't already have an SSD kicking around that you want to use, I would wait until the USB boot enabled Pi4 firmware is available and some testing has been done. There were some compatibility issues with the Pi3 series and USB booting, which hopefully will be less of a problem with the Pi4, but a wait and see attitude could save you some money.
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Gavinmc42
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Re: RP4(4gb) with M.2

Tue Jul 02, 2019 6:36 am

I suspect the same will be true for USB to NVME adapters but I haven't seen any reports from anyone who has actually tried them.
Anyone tried an Intel Optane in an USB caddy?

They should be better than Nand based SSD for lifetime writes.
I am not convinced NVMe based on 3D flash Nand is going to last that long, but they are cheaper.

At the moment I am thinking an USB3.0 externally power 2.5" HDD docking station.
Seem to have collected a bunch of 2.5" Sata drives including SSD.
How fast are Sata 2.5" rotating disc HDD?

Hmm two USB3.0 connectors, can a NAS Raid drive be done using a Pi4?
I just checked my wiring it is only 100Mbs, upgrading the home network for Pi4's is going to cost :lol:
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plugwash
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Re: RP4(4gb) with M.2

Tue Jul 02, 2019 7:57 pm

HawaiianPi wrote:
Tue Jul 02, 2019 6:03 am
An NVME SSD is many times faster than a SATA SSD, and will also be more expensive
That seems to depend on what capacity you are buying and where from.

When I look at 1TB SSDs from reputable SSD brands on scan computers I see.

NVME m.2: £98.48 (Intel)
SATA m.2: £105.98 (WD)
MSATA: £146.99 (samsung)
2.5 inch SATA: £106.31 (samsung)

hoopsurfer
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Re: RP4(4gb) with M.2

Thu Feb 13, 2020 8:34 am

For those who might want to try out a clean solution, I've rewritten and better integrated the code to support power management, shutdown and reboot on Geekwire's X856 and X735 add on boards to provide a better desktop-like experience.

I'd welcome any feedback/issues in the github repo: https://github.com/hoopsurfer/pdx

satadru
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Re: RP4(4gb) with M.2

Thu Feb 13, 2020 2:19 pm

I have a RPI4(4Gb) with a M.2 nvme ssd. See this:

viewtopic.php?t=245931&start=25

timrowledge
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Re: RP4(4gb) with M.2

Thu Feb 13, 2020 9:39 pm

hoopsurfer wrote:
Thu Feb 13, 2020 8:34 am
For those who might want to try out a clean solution, I've rewritten and better integrated the code to support power management, shutdown and reboot on Geekwire's X856 and X735 add on boards to provide a better desktop-like experience.
Excellent. I have an older X820 currently attached to 3B+ and several other assorted geekwork/suptronics boards that have done good service. The 735/856 look like a good combination to make a nice desktop machine.
I have only two issues with them

a) using the usb jumper between the Pi and ssd board makes for an ugly lump sticking out of most case designs and that just isn't nice. My current desktop Pi has the Pi in the middle of a repurposed PC powersupply case with fly-leads to the front and back with panel-mount sockets. I recently discovered some modular cable stuff that should help make that easier and neater - many short fly-leads are really stiff and not easy to squeeze into tight spaces or around sharp bends.
Take a look at https://preview.tinyurl.com/wgt7x7j to see one of the examples - neat hdmi/micro/midi with flex cable to a corresponding connector - an easy way to go fro mthe Pi dual micro-hdmi to a fullsize one at the front and back of a case. Similar stuff for USB etc can be found and I swear I found a panel mount option too.

b) I'm not sure about the power input for the 735; I thought it had a regulator and required a >6v input but it looks more like straight 5v in the doc your github page referred to. I've been using a surprisingly good quality open frame 5V/5A PSU that cost a whole C$6.97 shipped and shows astoundingly clean power output traces on a scope.

The only real problem with all this is that it will never fit into one of my replica AstroPi cases :-(
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andrum99
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Re: RP4(4gb) with M.2

Thu Feb 13, 2020 11:39 pm

plugwash wrote:
Tue Jul 02, 2019 7:57 pm
HawaiianPi wrote:
Tue Jul 02, 2019 6:03 am
An NVME SSD is many times faster than a SATA SSD, and will also be more expensive
That seems to depend on what capacity you are buying and where from.

When I look at 1TB SSDs from reputable SSD brands on scan computers I see.

NVME m.2: £98.48 (Intel)
SATA m.2: £105.98 (WD)
MSATA: £146.99 (samsung)
2.5 inch SATA: £106.31 (samsung)
NVMe is basically PCI express over the M.2 socket, optimised for SSDs. My laptop uses it for the SSD, an Intel 256GB unit, and helpfully also has space for a 2.5" SATA hard disk, which I've added myself. In future I could add a SATA SSD instead of the hard disk.

hoopsurfer
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Re: RP4(4gb) with M.2

Fri Feb 14, 2020 5:03 am

timrowledge wrote:
Thu Feb 13, 2020 9:39 pm
Excellent. I have an older X820 currently attached to 3B+ and several other assorted geekwork/suptronics boards that have done good service. The 735/856 look like a good combination to make a nice desktop machine.
I have only two issues with them ...
The X856 has a USB 3.1 to USB 3.1 hard connection (aligned port to port) that looks clean (the board is the size of the Pi). The X735 has been updated and has a USB C connection so power for everything is via a single USB C connection and is sized so it fits like a HAT. There are no loop back cables required and power for Pi, and SSD is through GPIO pins. With my improved power management code, reboot and power off can be done via a button or software (all commands work as expected).

The only cables leaving the setup are USB C power, two micro HDMI connectors to 4K displays, a small keyboard & mouse transceiver on one USB 2 port and optional is a Gigabit network connection. The remaining USB 3.1 A and C, and USB 2.0 A connectors on the Pi 4 are available. Still working on the case.

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