Overclocking

[jahboater]

AIUI 2.5A allows for a full set of peripherals. In my current (pun intended) experience the cable gauge (thickness) is the limiting factor, thin cables lose too much voltage way before reaching 2A.

I see the Official Pi3 supply uses very thick cable (18AWG) up from 20AWG for the old 2A official supply. The Amazon 3A supply uses thin 24AWG cable (mine does anyway).

[Nickcn]

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[jahboater]

This is a stable pi 3 overclock.

I can run memtester at same time as cpuburn-a53 for hours. But even with a fan, I hoover at around 82C and throttle. If I can get temps down 3° or so, I'll be fine.

Are you using a heastink AND a fan?
I hate fans. but just for a test I tried blowing a fan over the heatsink and running the memtester/cpuburn combination. The temperature has steadied at 57C (20C ambient). Very effective but horribly noisy (and its a vantec "stealth" 80mm fan).
I like the ModMyPi heatsink. It has longer fins than most, and rated at 25C/W.
http://www.modmypi.com/raspberry-pi/acc ... -kit-black

[Gerd]

Nickcn wrote:
v3d_freq=500
h264_freq=333

Hi Nickcn,
still learning myself, but I do think these both setting have no effect since you did not set force_turbo to 1.
Source: http://elinux.org/RPiconfig
" force_turbo=0
enables dynamic clocks and voltage for the ARM core, GPU core and SDRAM. When busy, ARM frequency go up to "arm_freq" and down to "arm_freq_min" on idle. "core_freq", "sdram_freq" and "over_voltage" behave the same. "over_voltage" is limited to 6 (1.35 V). Non default values for the H.264/V3D/ISP parts are ignored."

Or did this change and is just not documented in the wiki yet? E.g. hdmi_blanking=1 is not documented in the wiki.

[Nickcn]

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[dom]

Source: http://elinux.org/RPiconfig

That's not an official source. A better source would be
https://www.raspberrypi.org/documentati ... fig-txt.md

(but it may well still have omissions or errors. To submit a fix see here).

[Nickcn]

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[Nickcn]

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[JimmyN]

Hi Nickcn,
still learning myself, but I do think these both setting have no effect since you did not set force_turbo to 1.

Setting force-turbo to 1 keeps them at the high setting all the time, they won't scale down. You don't need to force turbo, all the gpu freqs will scale up and down right along with the arm_freq.

I just posted my current overclock settings in the "Winging a PI 3 Overclock" thread. viewtopic.php?f=29&t=139061
When idling I get this

Code: Select all

 vcgencmd measure_clock h264
frequency(28)=250000000

When I put a load on it and turbo kicks in I get this

Code: Select all

vcgencmd measure_clock h264
frequency(28)=588000000

So obviously they do scale you don't have to use "force turbo". But I use "gpu_freq" to set "core_freq, v3d_freq, isp_freq, and h264_freq" all at the same time, rather than individually. They are on the same PLL so you'll get the best results by using "gpu_freq" and setting them as a group so they match, rather than trying to set a different speed for each one individually.

[DougieLawson]

Ahh, this is what I was looking for. I can set the thermal threshold throttling higher than 85C on the pi3... I am thinking 95C

Code: Select all

temp_limit=95

Set it 5°C higher and your hard working RPI3B can make a decent cup of tea.

[dom]

Ahh, this is what I was looking for. I can set the thermal threshold throttling higher than 85C on the pi3... I am thinking 95C

You will find that you can't set this above 85, only lower it.
A heatsink would be the recommended way of avoiding the temperature limit.

[JimmyN]

Ahh, this is what I was looking for. I can set the thermal threshold throttling higher than 85C on the pi3... I am thinking 95C

85C may be the point where turbo turns off and it uses minimum settings for everything. From what I've seen throttling starts to occur around 80C, with a small decrease in the clock rate, and it slows down more and more as the temp increases.

[Nickcn]

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[rpdom]

Well then this is also inaccurate and should be fixed

As stated before, if you see an error or omission in the official documentation...

To submit a fix see here).

[Nickcn]

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[rpdom]

Thats not my job.

Seriously???

This is a community. So you just want to use the community and not give back to it?

[Nickcn]

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[DougieLawson]

Feel free to submit the fixes...

I am posting the errors in this community, how many moderators and foundation people are here? That is their job. This forum posting in regards to the errors should suffice as notification.

Excuse me, but 85% of the folks who answer threads on here are totally unpaid volunteers who are doing it because we want to be part of the community and are willing to share our expertise. Your kind of attitude will get you blocked by that corpus of knowledge, then I hope you enjoy working on your own.

This forum is all about give and take. If I want to use free (as in beer) software then my contribution to the forum is the pay back for that.

[Nickcn]

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[Saijin_Naib]

Are more CPU states possible than min/max/locked?
I know that currently we have 3 states for the CPU on the Raspberry Pi:
Original Clock Rate
overclock_max
overclock_min

Currently, we're only able to jump between min/max or lock ourselves at a given clockrate.

Is it possible to enable more steps for finer granularity in CPU speed steps? I think that'd be really awesome, and I know I would appreciate it. It'd make my rPi much happier for sure, seeing as currently it jumps between 125MHz and 1000MHz.

[AikonCWD]

Hi guys, reading this thrad I bumped my RPi3 with this config:

Code: Select all

force_turbo=1
arm_freq=1400
core_freq=550
over_voltage=6

sdram_freq=575
avoid_pwm_pll=1
sdram_schmoo=0x02000020
over_voltage_sdram_p=6
over_voltage_sdram_i=4
over_voltage_sdram_c=4

gpu_mem=256
v3d_freq=500
h264_freq=333

dtoverlay=sdhost,overclock_50=100

dtparam=audio=on
dtparam=spi=on

temp_limit=85
initial_turbo=60

start_x=1
overscan_scale=1

Looks stable, also I coded a small script to run some benchmarks, so we can compare the results to see who have the "faster" raspberry. Just copy and paste the following command on your RPi (you can use SSH/Putty too):

Code: Select all

curl https://raw.githubusercontent.com/aikoncwd/rpi-benchmark/master/rpi-benchmark.sh | sudo bash

Here is my result:

Code: Select all

Raspberry Pi Benchmark Test
Author: AikonCWD

temp=39.2'C
arm_freq=1200
core_freq=400
sdram_freq=450
microsd_clock=50.000 MHz

Running CPU test...
    total time:                          17.5519s
    temp=49.4'C

Running MEMORY test...
    total time:                          2.4863s
    temp=51.0'C

Running THREADS test...
    total time:                          8.9331s
    temp=52.1'C

Running HDPARM test...
    Timing buffered disk reads:  68 MB in  3.08 seconds =  22.06 MB/sec
    temp=46.2'C

Running DD WRITE test...
    536870912 bytes (537 MB) copied, 24.5015 s, 21.9 MB/s
    temp=42.9'C

Running DD READ test...
    536870912 bytes (537 MB) copied, 23.4359 s, 22.9 MB/s
    temp=41.9'C


AikonCWD's rpi-benchmark completed!

For CPU, MEMORY and THREADS, the smaller the better. Also check the temperature, mine was 52ºc max
For HDPARM, DD WRITE and DD READ, the bigger the better. Lets see who can get better results but lower temperatures

[321]

Is there a definitive list of the most stable over/under clocking settings for the different pi models a bit like this?

[ssvb]

You already have the definitive maximum settings as the defaults. Everything higher than this is a gamble.

[dorarosi]

Are more CPU states possible than min/max/locked?
I know that currently we have 3 states for the CPU on the Raspberry Pi:
Original Clock Rate
overclock_max
overclock_min

Currently, we're only able to jump between min/max or lock ourselves at a given clockrate.

Is it possible to enable more steps for finer granularity in CPU speed steps? I think that'd be really awesome, and I know I would appreciate it. It'd make my rPi much happier for sure, seeing as currently it jumps between 125MHz and 1000MHz.

Does anyone know something about this? I also would like to do small steps. It would also help when somebody posts a link to the files of the Raspbian image so I can build it myself.

Thanks
daniel

[PiGraham]

This is a OLD thread, but since it's been woken, does what's the story with overclock on PiZeroW?
raspi-config tells me it's not supported and the GUI configuration tool provides no option. I guess that means it can't be overclocked. Why is that?

Code: Select all

vcgencmd get_config arm_freq

shows

arm_freq=1000