AnAkkk
Posts: 5
Joined: Sat Aug 22, 2015 7:50 pm

Re: Overclocking

Tue Aug 25, 2015 12:10 am

ripednail wrote:Raspberry pi 2 b +

arm_freq=1050
over_voltage=4
core_freq=525
gpu_freq=350
sdram_freq=480
over_voltage_sdram_p=2
over_voltage_sdram_i=2
over_voltage_sdram_c=2
gpu_mem=256
Have you tried to run memtester a few times? I've tried to use 480 for SDRAM and after a while I still get some errors, while using arm 1000 over_voltage 2 core 500. I've also tried to set over_voltage to 4 and over_voltage_sdram to 2, didn't seem to change anything.

ripednail
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Re: Overclocking

Mon Aug 31, 2015 3:29 pm

:?:
Last edited by ripednail on Sat Apr 01, 2017 7:04 am, edited 1 time in total.

AnAkkk
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Re: Overclocking

Mon Aug 31, 2015 3:38 pm

ripednail wrote:
AnAkkk wrote:
ripednail wrote:Raspberry pi 2 b +

arm_freq=1050
over_voltage=4
core_freq=525
gpu_freq=350
sdram_freq=480
over_voltage_sdram_p=2
over_voltage_sdram_i=2
over_voltage_sdram_c=2
gpu_mem=256
Have you tried to run memtester a few times? I've tried to use 480 for SDRAM and after a while I still get some errors, while using arm 1000 over_voltage 2 core 500. I've also tried to set over_voltage to 4 and over_voltage_sdram to 2, didn't seem to change anything.
I went ahead and ran the following:
pi@raspberrypi ~ $ sudo memtester 700 10
memtester version 4.2.2 (32-bit)
Copyright (C) 2010 Charles Cazabon.
Licensed under the GNU General Public License version 2 (only).

pagesize is 4096
pagesizemask is 0xfffff000
want 700MB (734003200 bytes)
got 700MB (734003200 bytes), trying mlock ...locked.
Loop 3/10:
Stuck Address : ok
Random Value : ok
Compare XOR : ok
Compare SUB : ok
Compare MUL : ok
Compare DIV : ok
Compare OR : ok
Compare AND : ok
Sequential Increment: ok
Solid Bits : ok
Block Sequential : ok
Checkerboard : ok
Bit Spread : ok
Bit Flip : ok
Walking Ones : ok
Walking Zeroes : ok
8-bit Writes : ok
16-bit Writes : ok


....and so it passed. I suspect that the settings and timings are interrelated to each other as previously stated by others in this thread. The kernel update may have improved things https://github.com/Hexxeh/rpi-update

Feel free to give my settings a try and let me know what happens.
I did try your settings, and ended up setting sdram_freq to 460. Trying 470 and 480 always result into errors for me apparently. I think I already have the latest firmware version, I use OSMC though and it doesn't update the kernel through rpi-update.

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GTR2Fan
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Re: Overclocking

Sun Jan 17, 2016 4:42 pm

Don't take multiple passes of memtester as proof that your RAM is entirely stable.

The RAM on my Pi2B can pass the above test for hours at a time at 485MHz with over_voltage_sdram=2, but still suffers random web browser exits and Quake3 Arena and Quake Darkplaces lockups unless lowered to 475MHz. None of the 20-odd combinations of sdram_p, sdram_i or sdram_c overvolt settings I've tried here help one iota, so I've stuck with the global sdram overvolt setting.

It's definitely the RAM that's causing it because I've removed everything else from the equation by running stock speeds and voltages everywhere else when trying to find the source of the instability, and lowering the RAM clock is the only thing that affects and fixes it.

The best I can manage for what appears to be complete stability under the harshest of testing I can throw at it is...

Code: Select all

# Custom overclocking settings
dtoverlay=sdhost,overclock_50=100        <- The Sandisk Ultra UHS-I microSD card I use is perfectly happy with this.
force_turbo=1                            <- Locks sdhost to 100MHz for 42MB/s seq. reads from this card. Bye bye warranty!
arm_freq=1000
over_voltage=3
sdram_freq=475
over_voltage_sdram=2
core_freq=500
v3d_freq=500
h264_freq=333

# GPU RAM increased for gaming
gpu_mem=192
Quake3 Arena has vcgencmd measure_temp reporting 83°C at times even with the Pi in a large, well ventilated case with a 40mm fan pumping in room temperature air, so I'll be adding a small heatsink at some stage to avoid harmless (but potentially annoying when gaming) thermal-throttling during warmer weather.

It does go like stink now in some respects compared to running at stock clocks, so I'm not complaining. ;)
Pi2B Mini-PC/Media Centre: ARM=1GHz (+3), Core=500MHz, v3d=500MHz, h264=333MHz, RAM=DDR2-1200 (+6/+4/+4+schmoo). Sandisk Ultra HC-I 32GB microSD card on '50=100' OCed slot (42MB/s read) running Raspbian/KODI16, Seagate 3.5" 1.5TB HDD mass storage.

jahboater
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Re: Overclocking

Sun Jan 17, 2016 7:22 pm

To help the sdram stability you could try "disable_pvt=1" which sets a fixed conservative dram refresh rate (otherwise the sdram temp is measured twice per second and a more optimal refresh rate set dynamically). It worked for me, but later I added heatsinks to the sdram and the SoC and it was no longer needed (as well as allowing a voltage drop from 6 to 2). Now rock stable at 500MHz sdram.
"We are in the beginning of a mass extinction, and all you can talk
about is money and fairy tales of eternal economic growth."
- Greta Thunberg

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GTR2Fan
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Location: South East UK

Re: Overclocking

Sun Jan 17, 2016 7:26 pm

jahboater wrote:To help the sdram stability you could try "disable_pvt=1"...
Thank you. I will try this out. :)

EDIT: Bingo! That sorted it!

Now stable through a whole loop of memtester at sdram_freq=500MHz with overvoltage_sdram=2. Quake Darkplaces runs without freezing and my web browser no longer random exits. I'm off to do some more tweaking. Thanks again. :)

And...

Code: Select all

CONFIG: dtoverlay=sdhost,overclock_50=100
CLOCK : 100.000 MHz
CORE  : 500 MHz, turbo=1
DATA  : 512 MB, /root/test.dat
...
RESULT (AVG):
============
Overlay config                      core_freq   turbo   overclock_50    WRITE        READ        HDPARM
dtoverlay=sdhost,overclock_50=100      500        1     100.000 MHz   18.60 MB/s   39.93 MB/s   42.29 MB/s
Pi2B Mini-PC/Media Centre: ARM=1GHz (+3), Core=500MHz, v3d=500MHz, h264=333MHz, RAM=DDR2-1200 (+6/+4/+4+schmoo). Sandisk Ultra HC-I 32GB microSD card on '50=100' OCed slot (42MB/s read) running Raspbian/KODI16, Seagate 3.5" 1.5TB HDD mass storage.

dom
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Re: Overclocking

Sun Jan 24, 2016 7:01 pm

Interesting. I've done some digging and found the part of disable_pvt that seems to help. Can you test this firmware:
https://dl.dropboxusercontent.com/u/366 ... e_pvt2.zip

and report if sdram_freq=500 is stable on Pi2? You shouldn't need disable_pvt=1 with this.
I'm currently running sdram_freq=550 on 3 Pi's and they are okay (so far)...

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GTR2Fan
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Re: Overclocking

Sun Jan 24, 2016 7:15 pm

I'd love to give this a try, but I'm running Raspbian via NOOBS and am unsure as to which partition the new files should be dropped in. If you'd like to give me something to whack into the console to do the job then I'm more than happy to be a guinea pig. :)
Pi2B Mini-PC/Media Centre: ARM=1GHz (+3), Core=500MHz, v3d=500MHz, h264=333MHz, RAM=DDR2-1200 (+6/+4/+4+schmoo). Sandisk Ultra HC-I 32GB microSD card on '50=100' OCed slot (42MB/s read) running Raspbian/KODI16, Seagate 3.5" 1.5TB HDD mass storage.

dom
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Re: Overclocking

Sun Jan 24, 2016 7:23 pm

GTR2Fan wrote:I'd love to give this a try, but I'm running Raspbian via NOOBS and am unsure as to which partition the new files should be dropped in. If you'd like to give me something to whack into the console to do the job then I'm more than happy to be a guinea pig. :)
If you are on Pi then you want the files in /boot. Something like (untested):

Code: Select all

wget https://dl.dropboxusercontent.com/u/3669512/temp/firmware_pvt2.zip
unzip firmware_pvt2.zip
sudo mv start*.elf fixup*.dat /boot
sudo reboot
But be aware this is experimental. Backup your sdcard if it contains anything you don't want to risk losing.

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GTR2Fan
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Re: Overclocking

Sun Jan 24, 2016 7:33 pm

Hmm. Downloaded and unzipped, but then...

Code: Select all

sudo mv start*.elf fixup*.dat /boot
mv: failed to preserve ownership for ‘/boot/start_cd.elf’: Operation not permitted
mv: failed to preserve ownership for ‘/boot/start_db.elf’: Operation not permitted
mv: failed to preserve ownership for ‘/boot/start.elf’: Operation not permitted
mv: failed to preserve ownership for ‘/boot/start_x.elf’: Operation not permitted
mv: failed to preserve ownership for ‘/boot/fixup_cd.dat’: Operation not permitted
mv: failed to preserve ownership for ‘/boot/fixup.dat’: Operation not permitted
mv: failed to preserve ownership for ‘/boot/fixup_db.dat’: Operation not permitted
mv: failed to preserve ownership for ‘/boot/fixup_x.dat’: Operation not permitted
Pi2B Mini-PC/Media Centre: ARM=1GHz (+3), Core=500MHz, v3d=500MHz, h264=333MHz, RAM=DDR2-1200 (+6/+4/+4+schmoo). Sandisk Ultra HC-I 32GB microSD card on '50=100' OCed slot (42MB/s read) running Raspbian/KODI16, Seagate 3.5" 1.5TB HDD mass storage.

dom
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Re: Overclocking

Sun Jan 24, 2016 7:36 pm

That's fine. Fat can't preserve the Linux permissions but that doesn't matter.
Reboot and check "vcgencmd version" shows today's date.

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GTR2Fan
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Re: Overclocking

Sun Jan 24, 2016 7:57 pm

Rebooted and hashed-out disable_pvt=1 in the Raspbian config.txt via NOOBS recovery. Launched Raspbian and checked that today's date was shown via vcgencmd version, which it is.

I ran my own compile of Quake3 Arena that used to freeze my Pi2B in a matter of seconds with the RAM running at 500MHz without disable_pvt=1. It ran for a couple of minutes without a hitch.

I'm just off to run memtester for a loop or two to see how that goes. :)
Pi2B Mini-PC/Media Centre: ARM=1GHz (+3), Core=500MHz, v3d=500MHz, h264=333MHz, RAM=DDR2-1200 (+6/+4/+4+schmoo). Sandisk Ultra HC-I 32GB microSD card on '50=100' OCed slot (42MB/s read) running Raspbian/KODI16, Seagate 3.5" 1.5TB HDD mass storage.

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GTR2Fan
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Re: Overclocking

Sun Jan 24, 2016 9:13 pm

Two loops of memtester 700 successfully completed with no errors. Previously, it was failing at checkerboard on the first pass, so the problem appears to be resolved according to the testing I've carried out so far.

FYI, my current overclocking settings in Raspbian are...

Code: Select all

dtoverlay=sdhost,overclock_50=100
force_turbo=1
arm_freq=1000
over_voltage=3
sdram_freq=500
over_voltage_sdram=2
core_freq=500
v3d_freq=500
h264_freq=333
Note that anything below over_voltage=3 causes rapid crashes here when heavily stressing system-wide with a known-good PSU supplying at least 4.92V directly to the supply header pins, so maybe this needs bumping up from over_voltage=2 in the current raspi-config Pi2 overclocking settings?

Preliminary testing indicates that you seem to have fixed the problem, Dom. Congrats! I'm looking forward to seeing a few others testing this too so you have a sample base greater than 4. :)
Last edited by GTR2Fan on Sun Jan 24, 2016 9:19 pm, edited 1 time in total.
Pi2B Mini-PC/Media Centre: ARM=1GHz (+3), Core=500MHz, v3d=500MHz, h264=333MHz, RAM=DDR2-1200 (+6/+4/+4+schmoo). Sandisk Ultra HC-I 32GB microSD card on '50=100' OCed slot (42MB/s read) running Raspbian/KODI16, Seagate 3.5" 1.5TB HDD mass storage.

dom
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Re: Overclocking

Sun Jan 24, 2016 9:17 pm

You can probably drop over_voltage_sdram (if not specified over_voltage_sdram_p will be increased by default when sdram_freq > 450).

Does sdram_freq=550 work for you?

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GTR2Fan
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Re: Overclocking

Sun Jan 24, 2016 10:18 pm

Hashed-out over_voltage_sdram=2 and left the RAM at 500MHz. Quake3 Arena ran fine for a 5 minute test. One pass of memtester 700 passed all tests.

I'll try the ram at 550MHz but I've not explored up there so have no idea what to expect.
Pi2B Mini-PC/Media Centre: ARM=1GHz (+3), Core=500MHz, v3d=500MHz, h264=333MHz, RAM=DDR2-1200 (+6/+4/+4+schmoo). Sandisk Ultra HC-I 32GB microSD card on '50=100' OCed slot (42MB/s read) running Raspbian/KODI16, Seagate 3.5" 1.5TB HDD mass storage.

jahboater
Posts: 4929
Joined: Wed Feb 04, 2015 6:38 pm

Re: Overclocking

Sun Jan 24, 2016 10:31 pm

Does sdram_freq=550 work for you?
It didn't for me with the new firmware.
memtester 800m and about six small cpu bound processes failed after about 20 mins.

Code: Select all

over_voltage=2
over_voltage_sdram=2
arm_freq=1000
core_freq=500
sdram_freq=550
That's on a cherry picked Pi2 with a heatsink on the sdram chip (totally stable at 500Mhz).

Now trying 500Mhz on another Pi2 with no heatsinks that previously would never run at 500Mhz even with sdram overvoltage 6.

"disable_pvt=1" is known to have a small performance overhead (about 2% I think) because of the very conservative refresh rate - does this firmware change have any performance penalty?
"We are in the beginning of a mass extinction, and all you can talk
about is money and fairy tales of eternal economic growth."
- Greta Thunberg

milhouse
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Re: Overclocking

Sun Jan 24, 2016 10:35 pm

When testing 550MHz you may need to bump over_voltage_sdram higher than default - when using sdram_freq > 450MHz the new firmware will automatically use over_voltage_sdram=4, but you may need over_voltage_sdram=5 (or even 6) for stable 550MHz operation (5 works for me).
Last edited by milhouse on Sun Jan 24, 2016 10:36 pm, edited 1 time in total.

dom
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Re: Overclocking

Sun Jan 24, 2016 10:35 pm

jahboater wrote: "disable_pvt=1" is known to have a small performance overhead (about 2% I think) because of the very conservative refresh rate - does this firmware change have any performance penalty?
No performance impact. Sdram refresh will be normal with this firmware.

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GTR2Fan
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Re: Overclocking

Sun Jan 24, 2016 10:55 pm

Left over_voltage_sdram=2 hashed-out and upped the RAM to 550MHz. Quake3 Arena ran fine for a 5 minute test, but memtester 700 failed at checkerboard.

I'll leave the ram at 550MHz and put over_voltage_sdram=2 back in just to see what happens. Whatever, the problem at 500MHz seems to be fixed. Thanks for that. :)

EDIT: Just spotted milhouse's post. I'll try 5.

EDIT2: Failed memtester 700 at 550MHz with over_voltage_sdram=5 in the checkerboard test again. Never mind. I'm happy with 500MHz with no manual RAM voltage tweaks. :)
Pi2B Mini-PC/Media Centre: ARM=1GHz (+3), Core=500MHz, v3d=500MHz, h264=333MHz, RAM=DDR2-1200 (+6/+4/+4+schmoo). Sandisk Ultra HC-I 32GB microSD card on '50=100' OCed slot (42MB/s read) running Raspbian/KODI16, Seagate 3.5" 1.5TB HDD mass storage.

jahboater
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Re: Overclocking

Mon Jan 25, 2016 10:15 am

I tried 550Mhz again this time with over_voltage_sdram=5 and it failed in memtester early on. I tried over_voltage_sdram=6 which also failed.

For 500Mhz on a different Pi2, the overclock survived 11 hours of stress testing - which is a "result", that Pi was never stable with the old firmware. The sdram overvoltage was commented out.

It looks like the new firmware has made the standard Pi2 overclock in raspi-config stable!
With the raspi-config overclock (1000/500/500/ov 2), all four of my Pi2's would boot, run, do normal tasks like software builds - but would fail sustained stress testing.

It also means that all the people with their sdram set to 483MHz can change to a nice round number!

Thanks for this!
"We are in the beginning of a mass extinction, and all you can talk
about is money and fairy tales of eternal economic growth."
- Greta Thunberg

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GTR2Fan
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Re: Overclocking

Mon Jan 25, 2016 10:58 am

jahboater wrote:It looks like the new firmware has made the standard Pi2 overclock in raspi-config stable!
With the raspi-config overclock (1000/500/500/ov 2), all four of my Pi2's would boot, run, do normal tasks like software builds - but would fail sustained stress testing.
I'm glad I'm not the only person getting excited over this! Hehe! :D

As mentioned in one of my earlier posts, I still think the raspi-config Pi2 overclock settings need over_voltage=3 instead of 2 as the Pi2B here consistently crashes under system-wide heavy loading with a known-good (measured with an accurate DVM at the power pins on the GPIO header as no lower than 4.92V) PSU. This is with no heatsinks and in a very well ventilated and roomy case.

This problem doesn't show up with any of the conventional stress test programs in any combination that I've tried so far, but Quake Darkplaces and Quake3 Arena have it falling over in under a minute at 1GHz with over_voltage=2. Note that vcgencmd measure_temp reports 82°C with an ambient room temperature of 17°C when running Quake3 Arena at 1920x1080 with the overclocking settings in my sig despite the Pi2B not being 'boxed-in', so this probably isn't helping matters.

I'm just a little concerned that when some users are reporting that their overclock is stable, this may be because they haven't actually stress-tested to the load levels where instability may occur. Incidentally, despite being a competent PC overclocker dating back to the days when this involved getting a soldering iron out and changing crystals, I've never been at the top of any overclocking league tables due to always angling for complete stability under all testable circumstances rather than making too many assumptions regarding stability. :)
Pi2B Mini-PC/Media Centre: ARM=1GHz (+3), Core=500MHz, v3d=500MHz, h264=333MHz, RAM=DDR2-1200 (+6/+4/+4+schmoo). Sandisk Ultra HC-I 32GB microSD card on '50=100' OCed slot (42MB/s read) running Raspbian/KODI16, Seagate 3.5" 1.5TB HDD mass storage.

milhouse
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Re: Overclocking

Tue Jan 26, 2016 10:10 am

After additional testing with "memtester 850" I'm revising the spec of my sdram down from 550/+5 to 530/+4 - it fails on 530/+3, although I may eventually run it +5 for an increased margin of safety.

Any higher frequency, eg. 535, will fail in a single location on "Bit Flip", even with over_voltage_sdram=8:

Code: Select all

# memtester 850
memtester version 4.3.0 (32-bit)
Copyright (C) 2001-2012 Charles Cazabon.
Licensed under the GNU General Public License version 2 (only).

pagesize is 4096
pagesizemask is 0xfffff000
want 850MB (891289600 bytes)
got  850MB (891289600 bytes), trying mlock ...locked.
Loop 1/1:
  Stuck Address       : ok
  Random Value        : ok
  Compare XOR         : ok
  Compare SUB         : ok
  Compare MUL         : ok
  Compare DIV         : ok
  Compare OR          : ok
  Compare AND         : ok
  Sequential Increment: ok
  Solid Bits          : ok
  Block Sequential    : ok
  Checkerboard        : ok
  Bit Spread          : ok
  Bit Flip            : testing 144FAILURE: 0x00040000 != 0x00000000 at offset 0x00eb11fc.
  Walking Ones        : ok
  Walking Zeroes      : ok
  8-bit Writes        : ok
  16-bit Writes       : ok

Done.

dom
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Re: Overclocking

Tue Jan 26, 2016 12:13 pm

For more advanced sdram overclocking there is another control.

Code: Select all

vcgencmd schmoo 2 3 2 0 0 -2 -2 -2 -10
sets a number of sdram drive/delay parameters. The example I've given is the default but you can alter that. It doesn't take effect immediately, but on next sdram frequency change, so you need to ensure that occurs (e.g. by disabling and enabling the turbo mode).

Code: Select all

echo powersave | sudo tee /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
vcgencmd schmoo 3 3 2 0 0 -2 -2 -1 -10
echo ondemand | sudo tee /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
memtester 600
You can obviously try changing different numbers - just add or subtract 1 from the default and see if it helps, but for me increasing the first and penultimate ones seemed to help.

milhouse
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Re: Overclocking

Tue Jan 26, 2016 12:23 pm

If using force_turbo=1, what's the best way to force an sdram frequency change as I'm assuming that changing scaling_governor may have no effect.

dom
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Re: Overclocking

Tue Jan 26, 2016 12:25 pm

milhouse wrote:If using force_turbo=1, what's the best way to force an sdram frequency change as I'm assuming that changing scaling_governor may have no effect.
Probably best to remove force_turbo for this test.

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