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Upgrade Raspberry Pi 4 with a NVMe boot drive

alexellisuk.medium.com

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Re: Upgrade Raspberry Pi 4 with a NVMe boot drive

#21

Post by magicalhippo »

mmastrac wrote: post #8
timthorn wrote: post #7

Earlier quoted context omitted.

> An unnecessary additional failure point seems counterproductive One of the leading reasons for using USB attached storage on the Pi is to avoid SD card corruption issues.

FWIW I have not had any SD corruption issues after 1) using name-branded cards and 2) ensuring that I feed each Pi w/5.2V. In the end I bought a commercial 5V power supply, tweaked it up 5% and wired directly to the 5V pins on the Pi.

I'm running several Pi's from SD card, some for years, and the only issue I had was with one that randomly crashed.

Measured the resistance of the "USB charging cable" I had used for it and found it was 1 Ohm! So when the Pi peaked at 1A current draw, the cable dropped 1V.

Swapped it out for something proper (<0.1 Ohm), and haven't had issues since.

Re: Upgrade Raspberry Pi 4 with a NVMe boot drive

#24

Post by mmastrac »

magicalhippo wrote: post #21
mmastrac wrote: post #8

Earlier quoted context omitted.

FWIW I have not had any SD corruption issues after 1) using name-branded cards and 2) ensuring that I feed each Pi w/5.2V. In the end I bought a commercial 5V power supply, tweaked it up 5% and wired directly to the 5V pins on the Pi.

I'm running several Pi's from SD card, some for years, and the only issue I had was with one that randomly crashed. Measured the resistance of the "USB charging cable" I had used for it and found it was 1 Ohm! So when the Pi peaked at 1A current draw, the cable dropped 1V. Swapped it out for something proper (<0.1 Ohm), and haven't had issues since.

Same here. I even went as far as finding barrel-jack to USB connectors so I could wire thicker-gauge cables to the Pi.

In the end I gave up on trying to find low-ohm cables and just wired directly to the power supply. It's surprising how many cables just plain suck.

Re: Upgrade Raspberry Pi 4 with a NVMe boot drive

#27

Post by othercharles »

throwaway894345 wrote: post #20
othercharles wrote: post #12

Earlier quoted context omitted.

Generally speaking you can choose either power efficiency or a wide bus, but rarely both. If you want a crappy underpowered m.2 slot, probably Intel Atom is the cheapest route. High performance ARM with m.2 PCI, not sure, but guessing if it's around it probably isn't cheap

Let's say one has a friend who doesn't know what "a wide bus" refers to... What would be a good way of explaining it to said friend?

A single PCIe lane can draw 0.5 A, 4x rises to 2 A.

Separately, (random top Google result cutpaste):

    Architectural-level power optimization can target different system
    components such as CPU, caches, main memory,and buses [5, 6, 22, 4]. Power
    spent in off-chip buses can be a significant portion of the overall power
    budget. As an example, the core power consumption of Intel Celeron at
    266MHz is 16W, while its off-chip bus (for a standard configuration)
    operating at 133 MHz consumes 3.3W [12, 13]. The contribution of off-chip
    bus power consumption to the overall power budget increases even more for
    embedded systems with low-power processor cores and memories, making
    off-chip  buses  a  potential  candidate  for  power  optimization. Figure
    1 shows the power consumption due to off-chip data bus for several embedded
    benchmark codes as a percentage of the overall power consumption (which
    includes processor data path, caches, buses, TLB, register file,
    instruction issue logic, clock, and off-chip memory) for an
    embedded processor.  From this figure, we see that the off-chip data bus
    consumes between 9.8% and 23.2% of the total power consumed by the system
    depending on the benchmark being run. So, reducing the power consumption
    of the off-chip data bus would reduce the overall power consumption of
    the system to a considerable extent

Re: Upgrade Raspberry Pi 4 with a NVMe boot drive

#28

Post by lxe »

kzrdude wrote: post #23

One needs to login to read. I'm sorry, medium is not a very charitable blog host, and will cost the blog a large part of its audience with these new rules, unfortunately.

I'm getting pretty irritated that the Web is inundated with Medium. It used to be just a nice blog host, and now I don't even know what it is. Glad Substack is picking up steam.

Re: Upgrade Raspberry Pi 4 with a NVMe boot drive

#29

Post by tuatoru »

m-p-3 wrote: post #13
lifty wrote: post #10

Does anyone know any board that is similar to RPi 4, with 8GB of RAM or more and a SATA port or an nvme slot? ARM would be great.

Maybe there's something out there, but I don't know of any other SBCs than the Pi4 having more or equal to 8GB. If you can settle for 4GB, there's tye Rock Pi 4 which has a variant with on-board eMMC or an m.2 slot.

Also Friendlyarm's NanoPC T4.

M.2 PCIe x4, 4GB LPDDR3 (a bit old perhaps).

https://www.friendlyarm.com/index.php?route=product/product&...

Re: Upgrade Raspberry Pi 4 with a NVMe boot drive

#30

Post by an_opabinia »

rektide wrote: post #16
rwmj wrote: post #4

This is just plugging in NVMe over the USB 3 port? I was expecting this to be soldering something to PCIe lanes coming out of the SoC. Is this going to be any better than using an SSD with UAS which is what I'm doing already? ( https://rwmj.wordpress.com/2020/09/24/raspberry-pi-4-running... )

I am looking forward to a future where PCIe devices might be connected too. I would really appreciate it if someone other than Intel would kindly please start doing Thunderbolt. Now that USB4 is official, adding PCIe connectivity would be a very good perk for these next generation systems. So far though no one has registered interest. Please can someone other than Intel & Apple prioritize better connectivity? AMD? Me…

Many AMD enthusiast motherboards ship with Thunderbolt.

It's a straightforward technology to implement and I believe it is now royalty free. The only implementations are Intel's though and I'm sure they're expensive.

Expansion is a complicated business model. Apple doesn't even ship headphone ports. The AirPods are smash hit, not least because when you sell a $1,100 device a $100 accessory suddenly seems really well priced. PCs are similarly pretty high ticket items, that market supports a situation where spending $100 on custom internal PSU cabling is not that bad.

The Raspberry Pi is tough. Accessories cost more than 2x the device. It's a model that doesn't really make sense. You could say that people are buying these accessories, but really its greatest limiting factor is that it's too cheap, it's hard to psychologically deliver on the big ticket item + accessories shopping cart for it.

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