Raspberry Pi Forums

jahboater

I'm aware of and have used the config tools, the set is fine and works ok starting and stopping the fan according to the temperature settings. However, when the fan runs it's emits quite load whinny noise. I'm trying to find out if this level of noise is normal or if this new product normally runs ...

jahboater

I want to just have a lightweight fast operating system and Windows ce is about as lightweight as you can get. No it is not. For example, Tiny Core Linux is smaller and very much faster (it runs entirely in memory) than any version of Windows, even Wince. Raspberry Pi OS Lite is larger but is a goo...

jahboater

in python you can import TensorFlow or any other library on the argument, and that will do the job for you. With C you have to implement a complete backpropagtion algorithm exactly, As an interesting note, most of these libraries for Python, and Python itself, are actually written in C. Tensorflow ...

jahboater

What other resources should I look at? You can get some help from the compiler itself. That is, the compiler may check your program as far as possible and warn you of any mistakes before you try and run it. It can do checking at run-time as well, but that would slow the program down. Unlike an inte...

jahboater

I will have to research about all these terms, coming from such an easy language (python) where everything is interpreted and jumping to having to compile every time is already enough for me I suggest you stick with Python if you find typing "make" or "cc" more complicated than ...

jahboater

The simplest C program is usually: #include <stdio.h> int main( void ) { puts( "Hello world" ); } Paste or copy this into a file called "hello.c" To compile the program: $ make hello cc hello.c -o hello $ now to run the program type: $ ./hello Hello world $ Its pretty simple!!

jahboater

Side question : Should I use gcc or gcc-8 The default compiler on the Raspberry at the time of writing is GCC 8.3 which is very good. You can install a later version, currently 10.2, but is not necessary, unless perhaps you want early support for the draft C2x or faster code. Why should I use lncur...

jahboater

C++ is a multi-paradigm language. Of which OO is just one aspect. Yes I would learn C first, its much simpler. "Modern C++" is a huge language. Both are installed and ready to use on the Raspberry Pi OS. You definitely do not need an IDE. If you want to automate compilation, just use "...

jahboater

This looks like the same heatsink case without the tiny fans:
https://thepihut.com/products/aluminium ... berry-pi-4
Its cooling ability is far more than the Pi4 actually needs, even when heavily overclocked.

And its completely silent!!!

jahboater

Out of curiousity, does that apply when using 64 bit kernel/32 bit userland or 64 bit kernel/64bit userland on the 4B? I'm guessing the first is probably yes and the second probably no but I'm guessing. Aarch64 and ARM32 are not compatible at all, they are two different instruction sets. But, I pre...

jahboater

Can I build C++ application on Raspberry Pi 4 and run binary on Pi 3? Yes. The CPU's are different (the Pi3 has Cortex-A53's, the Pi4 has Cortex-A72's). However these are compatible. You might get a tiny performance benefit by targeting (with compiler options or by building on the Pi3) the Cortex-A...

jahboater

You need to open the file with a text editor.

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sudo nano /root/.vnc/config.d/vncserver-x11

The sudo is required because the file is likely owned by the special user "root" and not you.
Nano is a simple to use text editor (with a handy menu at the bottom of the screen).

jahboater

I would add: defaults,noatime,commit=600 to the mount options. The latter increases the risk if the USB drive is removed without un-mounting it first, or if there is an unplanned power outage. But it reduces writes and improves performance. Noatime is well known, it avoids a write to the super block...

jahboater

Because sync does--or at least, used to--return immediately, while the caches are being flushed to "disk", the traditional way to make sure the process is complete before moving on (say, to a logout), is to do it twice... sync; sync ...the second sync won't return a prompt until the first...

jahboater

While general reliability can be important and certainly most important for me, a common use of over clocking is to get a specific application that just wasn't quite fast enough already to run faster. For example, if a machine emulator for historic hardware doesn't run as fast as the original, over...

jahboater

Thanks Heater, I did not know about /proc/sys/vm/drop_caches, could be useful.

You don't need sudo for "sync" by the way.

jahboater

The ARM CPU's in the M1 are 5nm node size. For comparison, the latest Intel CPU's are 10nm and the SoC in the Raspberry Pi is 28nm. The previous Pi model was 40nm. The die shrink from 40nm to 28nm was expensive for a $35 computer. Question: How much do you think it would cost to get the Pi's SoC dow...

jahboater

Or to clear the disk cache, the best you can do is "sync" which writes any dirty blocks out.

jahboater

Gavinmc42 wrote: ↑
Tue Dec 01, 2020 7:16 am
Why not try it yourself?

+1

It costs nothing to try and only a few minutes to deploy on a spare SD card.
In the unlikely event that you do have a problem, just put the old card back.

I have been using Raspberry Pi OS 64-bit since day one and never had a problem.

jahboater

I'm researching this right now, and will publish the information along with detailed instructions on As its name suggests cpuburn-a53 is best for the Pi's with Cortex-A53 cpu cores. It does run on Pi4 with its Cortex-A72 cores but doesn't produce such a rapid rise in temperature. On the original Pi...

jahboater

Dragontail281 wrote: ↑
Mon Nov 30, 2020 5:24 pm
If I overclock while using RetroPie, does it stay in place when I switch out the SD cards?

No, everything goes when you switch cards.

But then its only a 30 second edit to set the overclock on Raspberry Pi OS:

sudo nano /boot/config.txt

jahboater

Take a look at Linpack ...

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https://www.howtoforge.com/tutorial/hpl-high-performance-linpack-benchmark-raspberry-pi/

jahboater

Do you still need pthreads?
See section 7.26 in the ISO standard.

jahboater

Random write speed 113 IOPS (target 500) - FAIL 113 IOPS is appalling! See the minimum spec for A1 class cards (1500 IOPS) that you should be using for an OS system disk: https://www.sdcard.org/developers/overview/application/index.html The Sandisk A1 class cards are popular and my experience has b...

jahboater

Whilst I am quite happy with the 100MB/s Samsung cards I'm curious to know if the Pi 4 is be capable of using the extra speed provided by the more expensive Kingston Canvas Go Plus or Kingston Canvas React Plus. The Pi4 SD card speed is twice that of older models. I suggest you look for A1 class SD...

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Re: Raspberry Pi 4 Fan - Sound/ Noise level

Re: Windows ce

Re: Need some more info about C

Re: Need some more info about C

Re: Need some more info about C

Re: Need some more info about C

Re: Need some more info about C

Re: Need some more info about C

Re: Raspberry Pi 4 Fan - Sound/ Noise level

Re: Building application on Pi4 to run on Pi3

Re: Building application on Pi4 to run on Pi3

Re: how open file via command line?

Re: Entry for fstab for USB3 thumb drive optimizing waer&tear

Re: How to clear cache in raspberry pi OS?

Re: Overclocking

Re: How to clear cache in raspberry pi OS?

Re: Too much heat versus power

Re: How to clear cache in raspberry pi OS?

Re: Raspberry PI OS 64-bit Release Date

Re: Overclocking

Re: Overclocking RetroPie vs Raspberry Pi OS

Re: CPU testing

Re: multi threading in c

Re: SD card speed failing , on a brand new class 10 card

Re: SD card speed >100MB/s ?