4b or CM4 that is the question

  1. I want to add a SATA drive to a Pi4b-8Gb. Choices are SSD or NVMe. I am told that NVMe is faster than the Pi can handle. Is this correct?
  2. Core recommends Argon ONE M2. Pi Hut recommends a cable: SSD to USB 3.0 Cable for Raspberry Pi. Which is better?
  3. I would prefer an NVMe for its smaller size even if I can’t get its max performance.
  4. I want it all enclosed in a single case… or I may as well just get the Pi Hut single cable.

Hi Peter,

From what I have read the limiting factor of a hard drive will be the USB controller. NVMe drives require a PCIe lane to reach their full speeds and that is populated on the Pi 4b. Check out this blog post from NewEgg: M.2 and NVMe SSDs: What are they and how do they benefit your PC? - Newegg Insider and Jeff Geerling The Raspberry Pi can boot off NVMe SSDs now | Jeff Geerling

It depends on what you intend, the Argon ONE M.2 is a NUC like form-factor which is very visual pleasing, and handles all of the cooling itself! The USB to SATA cable lets you attach a few more drives (but make sure you can draw enough power, either through a powered hub or through the Pi’s USB ports) with the USB cable you can run a few drives in RAID for a NAS setup.

For stuff like this there is rarely a ‘best’ setup, just something that best matches what you are after!


Hi Peter,

NVME drives require more power than normal SATA M.2 drives. The NVME drives will not work without a special drive enclosure and power source as the Pi 4’s USB ports cannot provide that high current. I think Argon one’s case and the added NVME enclosure provides power to the Pi via the power supply connected to the case and not directly to Pi as other cases.

Pi 4 has USB 3.0. So it is lesser than SATA 3. It will limit the speed. Posted my experience with a M.2 SSD here.


The other question was not addressed:
Should I start with a 4b or a CM4?

My 2 cents. (this post sparked my interest in CM4)

CM4 needs something to break out the connections and cool the processor, links below.
Pi 4 comes ready to plug in and just needs a heat sink or fan.
There are more accessories for the Pi 4. Case fans heat sinks etc.

Starting out I would recommend Pi 4; CM4 if a little more advanced.



Thanks people. Based on your input, I’ll probably go for the 4b-8Gb with the special housing.
Final and deal-breaking question:
I read on the official RPi site that they will ship 32bit versions until they run out. I definitely want a 64bit because I have software that only works correctly with 64bit. Can Core warranty that they will provide me with a 64bit version?


Hi Peter,

I haven’t been following the revisions that have been made too closely but I’ve had a couple of people ask recently if our 8GB boards have the chip ending in C0T on them.
The Pi foundation supplies all revisions of the 8GB Pi 4B to us under the same part number so we have no guarantee about which specific revision we will receive at any given time and are unable to open and inspect every unit received to check.

The board I opened last week was a C0T revision board so it’s fairly likely you’ll receive that one, but we can’t provide any warranty on the revision as we have no control over we receive.


I will wait until you find a way of identifying a 64bit Pi4b. It may end up being a 5b!

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Hey Peter,

All of the Pi 4 boards have 64-bit capable silicon, its just that the default RaspiOS is 32-bit!
You can get bit versions but they arent as tried and tested, Ubuntu is available by default on RPi imager:
Here’s a beta Raspberry Pi OS download page: Index of /raspios_lite_arm64/images

From a look around the C0T variant is just a bit of a change vs the other revision (supposed better thermals but cant confirm with my own testing).

Not too sure about RPi foundation coming out with a 5 but they did just push out the Pi Zero 2 and a bit before that the Pico(RP2040).


I’m quite prepared to wait for an official 64bit RPi. I’ve had a gut full of people assuring me that my 32bit laptops work with 64bit software.

From Raspberry Pi4 Datasheet (Attached here as well):

Raspberry Pi 4 Model B is the latest product in the popular Raspberry Pi range of computers. It offers ground-breaking increases in processor speed, multimedia performance, memory, and connectivity compared to the prior-generation Raspberry Pi 3 Model B+, while retaining backwards compatibility and similar power consumption. For the end user, Raspberry Pi 4 Model B provides desktop performance comparable to entry-level x86 PC systems.

This product’s key features include a high-performance 64-bit quad-core processor, dual-display support at resolutions up to 4K via a pair of micro-HDMI ports, hardware video decode at up to 4Kp60, up to 8GB of RAM, dual-band 2.4/5.0 GHz wireless LAN, Bluetooth 5.0, Gigabit Ethernet, USB 3.0, and PoE capability (via a separate PoE HAT add-on).
raspberry-pi-4-datasheet.pdf (427.2 KB)

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Hi Liam, before upgrading to Bullseye, I read an article (here) that the frequency boost to 1.8 GHz is possible only with the C0T chip (probably a misunderstanding). I have the earlier version of the chip (B version). I can get 1.8GHz max. frequency as well. Probably, cannot overclock it to 2.1GHz, which I do not plan to do anyway.

Regarding the thermals of the C0T chip on Pi 400, it has a heat sink about the size of the keyboard, in which it is housed. So, a big aluminum (Desalvo or Flirc or Argon case) or copper can serve the same purpose.

It is more of a matter of how heat is removed rather than the chips themselves. Perhaps, there is a minor optimization, but, how much it matters in a real world situation might not be that significant.