Setting a minimum set of CPU speed parameters

[simplesi]

The new turbo mode is great for the masses that just want to speed things up but still stay on the right side of the warranty line

But I'd like to have the fall back from 1Ghz be a bit more than 700MHz - is this easily possible to set?

regards

Simon

[dom]

The new turbo mode is great for the masses that just want to speed things up but still stay on the right side of the warranty line

But I'd like to have the fall back from 1Ghz be a bit more than 700MHz - is this easily possible to set?

regards

Simon

Only with force_turbo (and setting the warranty bit)

[simplesi]

Only with force_turbo (and setting the warranty bit)

Have you a link to where/how to do that?

(But it sounds a bit just like the old method of straight overclocking/overvolting rather than setting a fallback/minimum speed)

Simon

[dom]

Only with force_turbo (and setting the warranty bit)

Have you a link to where/how to do that?

(But it sounds a bit just like the old method of straight overclocking/overvolting rather than setting a fallback/minimum speed)

Yes, it pretty much makes overclock behave like it did before the cpufreq driver. Some info here:
http://www.raspberrypi.org/phpBB3/viewt ... 00#p169726

[Mortimer]

I read simplesi's query differently dom, and can't understand why the solution to his query should trigger the warranty bit.

As I understand it, he likes that fact that turbo mode now allows a warranty safe 1GHz boost to performance, but would like the idle speed to be LOWER than 700MHz, presumably to maximise power savings. I believe the same query is being asked on the "Auton, The Autonomous Sail Boat" topic too. Surely an underclock, should under any circumstances result in voiding the warranty?

[simplesi]

No - I want the idle speed to be higher than 700 MHz (But quite happy to not have high enough to require over-volting )

This is to even out the speed bump changes in running/editing Scratch programs

With Scratch - every little bit helps

Simon

[dom]

I read simplesi's query differently dom, and can't understand why the solution to his query should trigger the warranty bit.

As I understand it, he likes that fact that turbo mode now allows a warranty safe 1GHz boost to performance, but would like the idle speed to be LOWER than 700MHz, presumably to maximise power savings. I believe the same query is being asked on the "Auton, The Autonomous Sail Boat" topic too. Surely an underclock, should under any circumstances result in voiding the warranty?

arm_freq_min=100 (plus other _min parameters) is supported and won't set your warranty bit:
http://www.raspberrypi.org/phpBB3/viewt ... 00#p169726

[Mortimer]

OK, moot point anyway, as my interpretation of what simplesi wanted was wrong. Although I have to say, is there any advantage to setting a higher idle clock speed, especially for something like Scratch which is almost certainly going to trigger the turbo mode anyway by all accounts?

[simplesi]

is there any advantage to setting a higher idle clock speed, especially for something like Scratch which is almost certainly going to trigger the turbo mode anyway by all accounts?

You need to try it to see what its doing

During loading - CPU maxes - Turbo kicks in - effect 50% faster time to startup

Game (like asteroids) - lots of movement and sprites - turbo mode working all the time - great

Game - not so much CPU at times but with peaks - all of a sudden the speed of the game changes - not a great user experience (But could be made into a great feature for some games )

Also, during editing, some actions use CPU max and some don't so turbo cuts in and out and its like the same experience as having a sticky mouse

The "adult" Scratch user crowd are generally quite picky (sometimes outright hostile ) about Scratch's performance on the RPi so anything we can get done to bring them on-board to Scratch being usable on the RPi is to be greatly encouraged

Anyway - are we saying I can set arm_freq_min=800 and the RPi will recognise this (at school a ce moment so can't test)

Simon

[dom]

Anyway - are we saying I can set arm_freq_min=800 and the RPi will recognise this (at school a ce moment so can't test)

No, _min values above stock are currently not allowed. I'm considering allowing non-overvolted minimum settings.

[simplesi]

I'm considering allowing non-overvolted minimum settings.

Thank you

Simon

[simplesi]

Just a slight warning to others - I decided to see what my highest "minimum" CPIU freq was without overvolting so I added force_turbo=1 and upped the CPU to 800Mhz - test worked fine and then I decided to time something in 1GHz turbo mode so I just used sudo raspi-config to set that

The test went well and during it I decided to hover over the cpu freq icon and was suprised to find it reading 1Ghz all of the time

Basically, raspi-config didn't remove my force_turbo=1 entry and so my Pi was just set to overclock and overvolt all of the time!

I'm assuming that's the end of my warranty (not bothered really myself ) but just thought I'd warning others

Simon

[Salamander]

Anyway - are we saying I can set arm_freq_min=800 and the RPi will recognise this (at school a ce moment so can't test)

No, _min values above stock are currently not allowed. I'm considering allowing non-overvolted minimum settings.

Good idea dom. Right now my overclocking settings (which shouldn’t void warranty) are:
arm_freq=900
core_freq=450
sdram_freq=500
# no overvolt

I was thinking in something like:
# raspi-config "turbo" settings:
arm_freq=1000
core_freq=500
sdram_freq=500
over_voltage=6
# my previous no-warranty-voiding settings:
arm_freq_min=900
core_freq_min=450
sdram_freq_min=500
# no overvolt

Probably that would be my settings for autumn/winter. For spring/summer I will change to a 700-900 range. Climate in Spain is a little bit hotter than in UK

[misox12]

I actually trying to achieve the same. Set arm_freq_min=800 non-overvolted, so Raspi will auto-overclock to 1000hz overvolted.
Is there any solution to achieve this settings yet?

On the other hand, Salamander got interesting settings.
Do you think it's better to have nonstop 900mhz non-overvolted or 1000hz-600hz overvolted with fallback?
I.e. if I have webserver, so Raspi is nonstop @700mhz and after every request overclock to 1000hz. Do you think that it can cause some delay?

[Alkahest]

Anyway - are we saying I can set arm_freq_min=800 and the RPi will recognise this (at school a ce moment so can't test)

No, _min values above stock are currently not allowed. I'm considering allowing non-overvolted minimum settings.

I was wondering whether this is now possible? e.g. 800mhz as minimum with on demand step up to 1ghz

Thanks!