3 ms·

The problem for me is I attach a card to the top of the Pi for robot circuitry. That makes putting a heat sink or fan on the board awkward. I feel like having

The problem for me is I attach a card to the top of the Pi for robot circuitry. That makes putting a heat sink or fan on the board awkward. I feel like having to do this really compromises the versatility of the Pi. For now I am sticking to 3s until I hear the temp issue is solved.

ocdtrekkie 7y ago
Is placing the card on top a must, or can you do side by side with a 40-pin jumper cable?
- georgeecollins 7y ago
  You can do that, but many boards are really designed to sit on top of the card. In a robot that walks you don't have that much space and you want to mount everything as firmly as possible to avoid a bad connection from repeated vibrations. It is possible but so far it hasn't seem worth the hassle.
opencl 7y ago
The Pi 3 has the same thermal throttling issue as the 4, and the 4's performance under throttled conditions is much higher. Though IMO even calling it an issue is overblown, most phones and laptops cannot maintain their peak clocks under load for extended periods of time either. Intel calls it turbo boost so it's a feature instead of a bug.
- georgeecollins 7y ago
  Really? Because I run a Pi with a servo board on top that gets quite hot (too hot to touch) and it seems like CPU is performing time sensitive calculations (walking kinematics) adequately. It could be that the calculations are simple enough that they are insensitive to the throttling down. Do you have a suggestion how I could write some Python code to check if the 3 is throttling down? (Maybe a link to an example?) Maybe it wouldn't be an issue on the Pi 4 that I think it is. In that case I have been holding back on switching to a 4 for no good reason. This is very helpful, thank you.
  - sbierwagen 7y ago
    https://newscrewdriver.com/2018/09/06/detecting-raspberry-pi-thermal-throttling-from-console/ https://newscrewdriver.com/2018/09/06/detecting-raspberry-pi...
    - georgeecollins 7y ago
      Sam- thank you for this link. It is very helpful.
nlfwhulsdhouv 7y ago
You certainly don't _have_ to do anything, and under a fixed computational load the Pi4 should run cooler because of the better core architecture. However, you can get better performance by cooling. A fan off to the side of the board blowing between the two would probably work well if you want to keep it on top, but you're probably fine doing nothing as well.

ocdtrekkie 7y ago

Is placing the card on top a must, or can you do side by side with a 40-pin jumper cable?

georgeecollins 7y ago
You can do that, but many boards are really designed to sit on top of the card. In a robot that walks you don't have that much space and you want to mount everything as firmly as possible to avoid a bad connection from repeated vibrations. It is possible but so far it hasn't seem worth the hassle.

opencl 7y ago

The Pi 3 has the same thermal throttling issue as the 4, and the 4's performance under throttled conditions is much higher. Though IMO even calling it an issue is overblown, most phones and laptops cannot maintain their peak clocks under load for extended periods of time either. Intel calls it turbo boost so it's a feature instead of a bug.

georgeecollins 7y ago
Really? Because I run a Pi with a servo board on top that gets quite hot (too hot to touch) and it seems like CPU is performing time sensitive calculations (walking kinematics) adequately. It could be that the calculations are simple enough that they are insensitive to the throttling down. Do you have a suggestion how I could write some Python code to check if the 3 is throttling down? (Maybe a link to an example?) Maybe it wouldn't be an issue on the Pi 4 that I think it is. In that case I have been holding back on switching to a 4 for no good reason. This is very helpful, thank you.
- sbierwagen 7y ago
  https://newscrewdriver.com/2018/09/06/detecting-raspberry-pi-thermal-throttling-from-console/ https://newscrewdriver.com/2018/09/06/detecting-raspberry-pi...
  - georgeecollins 7y ago
    Sam- thank you for this link. It is very helpful.

nlfwhulsdhouv 7y ago

You certainly don't _have_ to do anything, and under a fixed computational load the Pi4 should run cooler because of the better core architecture. However, you can get better performance by cooling. A fan off to the side of the board blowing between the two would probably work well if you want to keep it on top, but you're probably fine doing nothing as well.