Review Raspberry Pi M.2 HAT+ Review: Low-cost, high-speed

[Admin]

Arriving months after its competitors, Raspberry Pi’s own M.2 HAT+ board brings low-cost, high-speed storage in the new HAT+ form factor.

Raspberry Pi M.2 HAT+ Review: Low-cost, high-speed : Read more

 

[Storage Wars]

There are a variety of RPi 5 NVMe HATs from various manufacturers. Some are bottom HATs with no possible access to the GPIO pins, some are top HATs that have no GPIO surface mount connector (for example, several Geekworm products), and some are top HATs that do have a GPIO connector. Some the products that do have GPIO connector claim to pull power from those pins, but no other signals.

The Pineberry Pi Hat Drive Review: Use NVMe SSDs with Your Pi from December 2023 states: “Hat Drive Top has an additional passthrough for the 40-pin GPIO, although it doesn’t use it. This passthrough is solely there to provide access to the GPIO, and eventually to use the best HATs.” Interestingly, several owners of both the top and bottom Pineberry HATS have anecdotally reported significant speed differences when using the same NVMe drive, with the faster speeds attributed to the top version of the HAT.

With the recent introduction of the official RPi NVMe HAT, they released a schematic of the official reference design for other manufacturers to follow. As you can see in the upper left corner of the schematic, it appears that the official RPi NVMe HAT is using several electrical connections on the GPIO pins besides power: https://datasheets.raspberrypi.com/m2-hat-plus/raspberry-pi-m2-hat-plus-schematics.pdf

This makes me wonder how stable 3rd party NVMe HAT products are in comparison to the official HAT. It also makes me wonder if we will see a flurry of second generation 3rd party products that incorporate some or all of the reference design attributes.

 

[bit_user]

The lack of 2280 support is pretty disappointing, as is the continued lack of clarity around PCIe 3.0 support. I don't currently own a Pi 5 and I'm wondering if I should continue to hold back, in hopes that PCIe 3.0 support will be ironed out in a future revision.

 

[MisterWho]

There are a variety of RPi 5 NVMe HATs from various manufacturers. Some are bottom HATs with no possible access to the GPIO pins, some are top HATs that have no GPIO surface mount connector (for example, several Geekworm products), and some are top HATs that do have a GPIO connector. Some the products that do have GPIO connector claim to pull power from those pins, but no other signals.

The Pineberry Pi Hat Drive Review: Use NVMe SSDs with Your Pi from December 2023 states: “Hat Drive Top has an additional passthrough for the 40-pin GPIO, although it doesn’t use it. This passthrough is solely there to provide access to the GPIO, and eventually to use the best HATs.” Interestingly, several owners of both the top and bottom Pineberry HATS have anecdotally reported significant speed differences when using the same NVMe drive, with the faster speeds attributed to the top version of the HAT.

With the recent introduction of the official RPi NVMe HAT, they released a schematic of the official reference design for other manufacturers to follow. As you can see in the upper left corner of the schematic, it appears that the official RPi NVMe HAT is using several electrical connections on the GPIO pins besides power: https://datasheets.raspberrypi.com/m2-hat-plus/raspberry-pi-m2-hat-plus-schematics.pdf

This makes me wonder how stable 3rd party NVMe HAT products are in comparison to the official HAT. It also makes me wonder if we will see a flurry of second generation 3rd party products that incorporate some or all of the reference design attributes.

What do you mean by "stable"?

I can see from the upper left coner of the schematics, that both boards use the same pins.

3.3V, 5V, GND, ID_SD (I2C_Data for the HAT-Overlay), ID_SC (I2C_Clock for the HAT-Overlay)

significant speed differences when using the same NVMe

Interesting, got a link?

 

[Storage Wars]

What do you mean by "stable"?

All of the 3rd party NVMe products I have seen list a plurality drives/controllers that are flat-out incompatible. And that list has only grown over time. I have also read reports of stability issues with some drives that are not on those compatibility lists. The official product reportedly does not have those issues.

Source Link: https://www.raspberrypi.com/news/m-2-hat-on-sale-now-for-12/

Extensive drive compatibility​

While we were doing all this, we took the opportunity to test a wide variety of NVMe drives and other peripherals, and to investigate the various issues we found. In one case we worked with a manufacturer to develop a fix for a drive that didn’t work correctly; this one turned out to be a startup timing issue in the drive firmware, preventing the PCIe controller inside BCM2712 from recognising the drive.

And of course it takes time to write firmware, and to build the production processes, material pipeline, and test systems required to build tens of thousands of units of a product each and every month. But with all this done, we’re pleased to be in a position to launch. If your Raspberry Pi 5 has up-to-date firmware, and an M.2 HAT+ attached, an installed PCIe device will be probed at power on and, if it’s an NVMe drive, it will be available as a boot source.

I can see from the upper left coner of the schematics, that both boards use the same pins.

It would make complete sense for both boards share that design, however, the title of that schematic is: "Raspberry Pi M.2 M-Key HAT+" and I don't see a detail that indicates it refers to both boards. Please share if you do.

In the meantime, see this quote::

Source Link: https://www.raspberrypi.com/news/introducing-raspberry-pi-5/

From early 2024, we will be offering a pair of mechanical adapter boards which convert between this connector and a subset of the M.2 standard, allowing users to attach NVMe SSDs and other M.2-format accessories. The first, which conforms to the standard HAT form factor, is intended for mounting larger devices. The second, which shares the L-shaped form factor of the new PoE+ HAT, supports mounting 2230- and 2242-format devices inside the Raspberry Pi 5 case.

Interesting, got a link?

Don't have time to find them all, but here's one:

https://www.amazon.com/gp/customer-reviews/RS4PWWVZUHY89?ref=pf_vv_at_pdctrvw_srp

... which is a review for this product:

https://www.amazon.com/Pineberry-Pi-HatDrive-Bottom-Raspberry/dp/B0CTYGVVS8

 

[MisterWho]

One review without any numbers is, well...not very meaningful.

Compared to these, the transfer speeds are mostly identical:

https://www.tomshardware.com/raspbe...i-hat-drive-review-use-nvme-ssds-with-your-pi

https://bret.dk/pineberry-pi-hatdri...neBerry-Pi-HatDrive-Review-Benchmarks-Testing