Hello,
In Pimoroni’s rpi5 nvme base drive compatibility page, Team MP33 is listed. That nvme power rating is 3.3V@2.5A which roughly converts to 5V@1.6A.
Given that the pin 1 & 2 of the rpi5 16pin PCIe connector are rated for a total of 1A, how does that MP33 work & is listed as compatible?
Thank you.
@aboulfad The drive is running at x1 instead of x4 which means it has a much lighter workload already. The system can respond to momentary spikes of current with the caps in the buck converter, and the flat-flex cable will also be able to exceed 1A for a short time. Between these things, we’ve found most drives are happy with the power available to them.
Thank you, what about the different variants of MP33: MP33Q or MP33 PRO ? Or the MP34?
Here is a voltage/current chart of a Crucial P3-Pro, also rated at 2.5A:
In the middle part, there is heavy I/O. As you can see, there are some small spikes up to 1.2A, but that is it. When testing with other drives, I see a very similar pattern, 1.4A is the limit I reached.
Note this is a headless Pi5 without peripherals (i.e. no display, no USB). So the absolute level is low from the beginning (as you can see from the idle-phases).
Hi, thank you, that is very useful. I couldn’t find much or any info on Crucial P3 Pro. Though the P3+ measured idle/min/max is way less than 2.5A@3.3V as measured by Tomshardware.
I wonder what’s the current supply upper limit for that flex ribbon & what happens when that limit is reached under sustained load?
PS: is this what was used to measure power/current ? If yes, this is an external measurement device that is measuring all power consumption of rpi5 & its peripherals incl the nvme drive ?
Exactly. You can see that the Pi5 itself has an idle current draw of about 550mA. Besides the NVME, the DuT did not have any peripherals. So the NVME current is the difference (about 650mA during the spikes you can see).
That’s indeed low consumption and correlates very well with Tomshw measurements. Now I get what @guru mentioned above about rpi5 running 1x PCIe. After much reading, I think the Crucial P3 is probably the best buck for the bank. Thank you : )
