cnx, 2 months ago

@gyptazy, youyeetoo designed an entire case as a heat sink and I think that is ingenious. That being said, it feels a wee warm even running at 3.6 W, is active cooling necessary on heavy load?

gyptazy, 2 months ago

@cnx yeah it gets really hot and active cooling should be done. According to geekbench the performance decreases in long term if not cooled.

cnx, 2 months ago

Thanks, @gyptazy, I’ll keep an eye on it and perhaps getting a minifan once it gets hot.

gyptazy, 2 months ago

@cnx better to have one. Do you also have the drivers in place to read the thermal values? I’m not sure if they’re finally in vanilla kernel present (currently not following the RV64 support for VF2 anymore).

cnx, 2 months ago

@gyptazy, supposedly it was merged in Linux 6.4, but I’m using OEM kernel at the moment with that patch included. It’s maxxing out one core at 5–6 W and hovering around 56°C.

gyptazy, 2 months ago

@cnx aha?! That’s pretty interesting!

In my tests (https://gyptazy.ch/misc/collection-of-images-and-information-for-risc64-board-visionfive2/) I came always over 70° without active cooling. Running geekbench it consumed more than 13W.
Measured with a Refoss power plug. Even in idle I had more than 7W.

(measured without any device attached/plugged in, running from SD (no NVME attached), so basically no additional consumers).

cnx, 2 months ago

FWIW @gyptazy, the current power usage is drawn for practically just running git pull of a huge repository (Guix) and I’m running on eMMC. Just curious, was your power supply 5 V or 12 V?

gyptazy, 2 months ago

@cnx PSU from a RPi 5Volt, 3 Ampere (15W). Seeing other benchmarks are more to my measured one, but I’ll try another power measure plug to compare the results

cnx, 2 months ago

Interesting, @gyptazy, I vaguely recall someone getting confused of the board using higher wattage under the same load on 5 V than 12 V. Let’s say that is the case, what could cause that difference in power consumption?

gyptazy, 2 months ago

@cnx I'd more assume that one power meter is not accurate.

Having a look at the specs of the VF2 doesn’t solve the issue for me:
https://doc-en.rvspace.org/VisionFive2/Datasheet/VisionFive_2/power_consumption.html

So the standby is 4.1W in table 1 and full 9.3W in table 3.

But I think element 1 and 2 in table 3 are mixed? They’re the same except of a fan on top, but with fan lower consumption?

cnx, 2 months ago

@gyptazy, I suppose because chips are more efficient in their operating temperature range, though I didn’t know it can be that drastic.

cnx, 26 days ago

@gyptazy, speaking of the VF2 and fans, do you happen to know if the fan’s 2-pin power delivery is always 5 V or is it the same as that of the power supply?

gyptazy, 26 days ago

@cnx honestly, I haven't validated it but according to https://doc-en.rvspace.org/VisionFive2/PDF/VisionFive2_QSG.pdf on page 21, I'd guess it's always max. 5V.

But maybe @DesRoin can tell us more here.

cnx, 26 days ago

Thanks, @gyptazy, until further input from @DesRoin, I’d interpret that as the pin is 5 V like the GPIO ones. Worst case it’ll just spin really fast and I should be able to notice that?

gyptazy, 26 days ago

That's also how I'd understand this. Just had another look at the docs, where it defines the input power support on page 15 with:

• Power adapter with fixed voltage from 5 V to 20 V on the USB C power port
• Support USB Type C PD 2.0, 9 V/2 A, 12 V/2 A, 15 V/2 A, 20 V/2 A

So (but it's still guessed), it is fixed to the 5V for the fan.

CC: @DesRoin

DesRoin, 26 days ago

@gyptazy @cnx it ought to be fixed 5V since otherwise it'd be completely unusable.
If you use a multi voltage power supply the VF2 and the power supply decide together what voltage the box runs on (hence it can be either 5V or 12V and you wouldn't know unless the PSU shows it), however the voltage being output to the peripherals on the board are always the same, if they weren't you'd fry a fair bit of conductors on there 😅

kzimmermann, 3 months ago

@gyptazy beautiful! This whettens my appetite concerning trying out more ARM-based SBCs that are not the Raspberry Pi <3

kzimmermann, 3 months ago

@gyptazy oh, just saw it's riscv... but still, other SBCs not RPi-based!