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by jahboater
Fri Dec 04, 2020 12:27 pm
Forum: HATs and other add-ons
Topic: Raspberry Pi 4 Fan - Sound/ Noise level
Replies: 16
Views: 872

Re: Raspberry Pi 4 Fan - Sound/ Noise level

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 ...
by jahboater
Fri Dec 04, 2020 9:51 am
Forum: Other
Topic: Windows ce
Replies: 6
Views: 598

Re: Windows ce

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...
by jahboater
Fri Dec 04, 2020 9:40 am
Forum: C/C++
Topic: Need some more info about C
Replies: 68
Views: 2529

Re: Need some more info about C

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 ...
by jahboater
Fri Dec 04, 2020 9:15 am
Forum: C/C++
Topic: Need some more info about C
Replies: 68
Views: 2529

Re: Need some more info about C

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...
by jahboater
Fri Dec 04, 2020 1:51 am
Forum: C/C++
Topic: Need some more info about C
Replies: 68
Views: 2529

Re: Need some more info about C

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 ...
by jahboater
Fri Dec 04, 2020 1:35 am
Forum: C/C++
Topic: Need some more info about C
Replies: 68
Views: 2529

Re: Need some more info about C

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!!
by jahboater
Fri Dec 04, 2020 1:28 am
Forum: C/C++
Topic: Need some more info about C
Replies: 68
Views: 2529

Re: Need some more info about C

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...
by jahboater
Fri Dec 04, 2020 1:23 am
Forum: C/C++
Topic: Need some more info about C
Replies: 68
Views: 2529

Re: Need some more info about C

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 "...
by jahboater
Thu Dec 03, 2020 11:20 pm
Forum: HATs and other add-ons
Topic: Raspberry Pi 4 Fan - Sound/ Noise level
Replies: 16
Views: 872

Re: Raspberry Pi 4 Fan - Sound/ Noise level

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!!!
by jahboater
Wed Dec 02, 2020 10:56 pm
Forum: C/C++
Topic: Building application on Pi4 to run on Pi3
Replies: 3
Views: 340

Re: Building application on Pi4 to run on Pi3

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...
by jahboater
Wed Dec 02, 2020 6:01 pm
Forum: C/C++
Topic: Building application on Pi4 to run on Pi3
Replies: 3
Views: 340

Re: Building application on Pi4 to run on Pi3

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...
by jahboater
Wed Dec 02, 2020 10:19 am
Forum: General discussion
Topic: how open file via command line?
Replies: 2
Views: 147

Re: how open file via command line?

You need to open the file with a text editor.

Code: Select all

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).
by jahboater
Wed Dec 02, 2020 2:28 am
Forum: Troubleshooting
Topic: Entry for fstab for USB3 thumb drive optimizing waer&tear
Replies: 3
Views: 167

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

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...
by jahboater
Tue Dec 01, 2020 7:20 pm
Forum: General discussion
Topic: How to clear cache in raspberry pi OS?
Replies: 11
Views: 529

Re: How to clear cache in raspberry pi OS?

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...
by jahboater
Tue Dec 01, 2020 6:35 pm
Forum: Advanced users
Topic: Overclocking
Replies: 1173
Views: 686745

Re: Overclocking

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...
by jahboater
Tue Dec 01, 2020 4:33 pm
Forum: General discussion
Topic: How to clear cache in raspberry pi OS?
Replies: 11
Views: 529

Re: How to clear cache in raspberry pi OS?

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.
by jahboater
Tue Dec 01, 2020 4:22 pm
Forum: Off topic discussion
Topic: Too much heat versus power
Replies: 29
Views: 1615

Re: Too much heat versus power

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...
by jahboater
Tue Dec 01, 2020 10:44 am
Forum: General discussion
Topic: How to clear cache in raspberry pi OS?
Replies: 11
Views: 529

Re: How to clear cache in raspberry pi OS?

Or to clear the disk cache, the best you can do is "sync" which writes any dirty blocks out.
by jahboater
Tue Dec 01, 2020 8:08 am
Forum: Raspberry Pi OS
Topic: Raspberry PI OS 64-bit Release Date
Replies: 36
Views: 9186

Re: Raspberry PI OS 64-bit Release Date

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.
by jahboater
Tue Dec 01, 2020 7:54 am
Forum: Advanced users
Topic: Overclocking
Replies: 1173
Views: 686745

Re: Overclocking

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...
by jahboater
Mon Nov 30, 2020 6:52 pm
Forum: General discussion
Topic: Overclocking RetroPie vs Raspberry Pi OS
Replies: 2
Views: 134

Re: Overclocking RetroPie vs Raspberry Pi OS

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
by jahboater
Mon Nov 30, 2020 2:33 am
Forum: Beginners
Topic: CPU testing
Replies: 3
Views: 137

Re: CPU testing

Take a look at Linpack ...

Code: Select all

https://www.howtoforge.com/tutorial/hpl-high-performance-linpack-benchmark-raspberry-pi/
by jahboater
Mon Nov 30, 2020 2:30 am
Forum: C/C++
Topic: multi threading in c
Replies: 7
Views: 607

Re: multi threading in c

Do you still need pthreads?
See section 7.26 in the ISO standard.
by jahboater
Sun Nov 29, 2020 7:08 pm
Forum: General discussion
Topic: SD card speed failing , on a brand new class 10 card
Replies: 9
Views: 445

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

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...
by jahboater
Sat Nov 28, 2020 3:34 pm
Forum: General discussion
Topic: SD card speed >100MB/s ?
Replies: 4
Views: 255

Re: SD card speed >100MB/s ?

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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