Coolbook on MBA 11. Feedback from the creator

[gimmi80]

Hi,
I, as many of you, were confused on the best settings for coolbook on MBA 11'.
I decided to ask the editor and he agreed to have the answer published here.
I hope it will help. It helped me.

Dear author of coolbook,

How are you?[...]
I have a MacBook air 1.6 GHz (late 2010 model). The setting I'm currently using (with battery power) are:
1200MHz at 0.875v
1400MHz at 0.875v
1600MHz at 0.875v
Throttling is set to high.

I discussed with other users about my settings and I've been criticized based on the rationale that all these settings are not needed and that 1600MHz at 0.875v should be the only setting. With this configuration, even if the CPU is always running at the highest settings, calculations are performed faster and therefore the final demand of power (and battery consumption) should be less.

What's your idea about this? Is one setting better than multiple settings with high throttling?

Also, many user are discussing their success undervolting the MacBook air 2010 (as reported in macrumors forum, I can't post the link as I'm on a iPhone right now).
100% of the coolbook user report success undervolting the CPU to 0.875v. Therefore we would like to go lower and try 0.85 and 0.825v. I'm not too familiar with Terminal and I would prefer to modify this settings from the GUI.
Could you provide us a revision of coolbook that would allow us to do that?

To conclude, I realize that the settings should be customized to the user needs, therefore hard to standardize, but, as a clarification is needed, your feedback would be greatly appreciated.

Regards,
Alex

 

[gimmi80]

His answer:

Hi Alex,

I think that it's unnecessary to use lower frequencies with the same voltage, unless you want to use the temp limit.
If you "hold back" the number of instructions performed at full load, the CPU will become cooler.
Every change in frequency is costing a number of cycles, so just going up and down in frequency for every CPU load spike is not recommended.

Using a "B/2" setting for battery, may give you some additional runtime.

There are very few computers benefiting from the "LoopCnt" setting in the terminal. I have personally only seen one model that could find extra voltages.
The 11" Air is not one of them.

Sincerely,

Magnus

 

[Mac32]

Hmm, my experience is that forcing the machine to run at 800mhz and then 1.6ghz at the same volt setting (having only one cpu freq in CoolBook), 1.6ghz will still make the machine warmer than 800mhz. Maybe the CPU is working harder and thus creating more heat, even if the volt setting is the same..maybe.. anyone else?

 

[iRun26.2]

His answer:

Hi Alex,

I think that it's unnecessary to use lower frequencies with the same voltage, unless you want to use the temp limit.
If you "hold back" the number of instructions performed at full load, the CPU will become cooler.
Every change in frequency is costing a number of cycles, so just going up and down in frequency for every CPU load spike is not recommended.

Using a "B/2" setting for battery, may give you some additional runtime.

There are very few computers benefiting from the "LoopCnt" setting in the terminal. I have personally only seen one model that could find extra voltages.
The 11" Air is not one of them.

Sincerely,

Magnus

It's almost like he didn't answer your question about other voltage options. Maybe it isn't possible?

 

[aleni]

why in the hell would anyone want their macbook air to run at 1.6ghz only? maybe it's going to benefit if doing some video processing all day long 24 hours/day.

when i'm downloading big files from the internet while reading a book on my bed, the air is idling and only running at 800mhz, not needed for running it at 1.6ghz just for downloading a file in safari. so it saves a lot of battery life.

 

[yegon]

I've a quick question about coolbook. I've been using it, successfully, at 1.6ghz .875v only. If you actually set up a 800mhz, how do you switch between them? The "set" button always seems to be greyed out. Or does it do it automatically if you have 2 profiles?

 

[wressus]

Can anybody with the 1.4Ghz respond with the voltage there able to chose? I can only chose down to 0.9V, and the only frequency that i can alter is the 1.4Ghz!? But ive read here on the forum about people being able to chose 0.875 on the 1.4Ghz?


As for a ordinary PC BIOS, the voltage that you can chose isnt relevant to the CPU used, as far as i can remember?

 

[gimmi80]

It's almost like he didn't answer your question about other voltage options. Maybe it isn't possible?

Yes, he did not answer. Maybe is not possible.

 

[gimmi80]

why in the hell would anyone want their macbook air to run at 1.6ghz only? maybe it's going to benefit if doing some video processing all day long 24 hours/day.

when i'm downloading big files from the internet while reading a book on my bed, the air is idling and only running at 800mhz, not needed for running it at 1.6ghz just for downloading a file in safari. so it saves a lot of battery life.

From what he says, it seems like running at 800Mhz or 1600Mhz does not make much of a difference (or let's say it does not make a significant difference in battery time). The option he gave for saving battery life is using the 800MHz.

His bottom line is that this software was developed to keep the old generation MBA cool, the battery saving is an extra but is not the main feature.

 

[BlackMax]

when i'm downloading big files from the internet while reading a book on my bed, the air is idling and only running at 800mhz, not needed for running it at 1.6ghz just for downloading a file in safari. so it saves a lot of battery life.

It shouldn't make a difference in battery life if you are running at 800Mhz or 1.6GHz if both speeds are pulling the same voltage of .875v.

If you MBA is pulling .875 volts whether it is running at 800Mhz or 1.6GHz, the battery drain should be exactly the same.

Now heat generation might be a different story between 800Mhz and 1.6GHz, as always running at 1.6GHz probably produces some more heat that dropping to 800MHz for non-CPU intensive tasks.

 

[BlackMax]

His answer:

Hi Alex,

I think that it's unnecessary to use lower frequencies with the same voltage, unless you want to use the temp limit.
If you "hold back" the number of instructions performed at full load, the CPU will become cooler.
Every change in frequency is costing a number of cycles, so just going up and down in frequency for every CPU load spike is not recommended.

Isn't Magnus basically saying it makes more sense to run a single frequency, the higher available, at the lowest possible voltage as opposed to having multiple frequencies at the same voltage and constantly having to switch between them (which uses even more clock cycles)?

The only time it makes sense to have multiple frequencies is when your highest frequency is not capable of running at your lowest voltage... But with the MBA that is not the case as the 11.6" MBA can run at .875v at 1.6Ghz/1.4Ghz all day long.

 

[Psilocybin]

Isn't Magnus basically saying it makes more sense to run a single frequency, the higher available, at the lowest possible voltage as opposed to having multiple frequencies at the same voltage and constantly having to switch between them (which uses even more clock cycles)?

The only time it makes sense to have multiple frequencies is when your highest frequency is not capable of running at your lowest voltage... But with the MBA that is not the case as the 11.6" MBA can run at .875v at 1.6Ghz/1.4Ghz all day long.

my 13.3 cant do highest freq at lowest voltage.

 

[iRun26.2]

It shouldn't make a difference in battery life if you are running at 800Mhz or 1.6GHz if both speeds are pulling the same voltage of .875v.

If you MBA is pulling .875 volts whether it is running at 800Mhz or 1.6GHz, the battery drain should be exactly the same.

The power taken by the processor may be the same but, if it takes twice as long for the 800MHz mode to complete a calculation, the overall efficiency will go down because the other system components are active longer.

 

[iRun26.2]

my 13.3 cant do highest freq at lowest voltage.

What is the best you can do, and what happens when your 13.3" can't handle the lower voltages?

It sounds like the 11.6" ULV machines are having more success at the lowest voltage settings.

 

[Psilocybin]

What is the best you can do, and what happens when your 13.3" can't handle the lower voltages?

It sounds like the 11.6" ULV machines are having more success at the lowest voltage settings.

It kernel panics on the lowest voltage which is .9250
I use 2 settings higher than the voltage that kernel panics. .9500

 

[gimmi80]

Isn't Magnus basically saying it makes more sense to run a single frequency, the higher available, at the lowest possible voltage as opposed to having multiple frequencies at the same voltage and constantly having to switch between them (which uses even more clock cycles)?

The only time it makes sense to have multiple frequencies is when your highest frequency is not capable of running at your lowest voltage... But with the MBA that is not the case as the 11.6" MBA can run at .875v at 1.6Ghz/1.4Ghz all day long.

I agree with you.
If that's the situation (one frequency with lowest voltage available), why can not we go lower. What about .85v or .825v?
Would be nice to try.
My 11' MBA is running fine at .875v 1.6MHz.

 

[aleni]

It shouldn't make a difference in battery life if you are running at 800Mhz or 1.6GHz if both speeds are pulling the same voltage of .875v.

If you MBA is pulling .875 volts whether it is running at 800Mhz or 1.6GHz, the battery drain should be exactly the same.

Now heat generation might be a different story between 800Mhz and 1.6GHz, as always running at 1.6GHz probably produces some more heat that dropping to 800MHz for non-CPU intensive tasks.

do higher temp and increased fan draw less power than clock cycles at the same voltage?

 

[wressus]

Isn't Magnus basically saying it makes more sense to run a single frequency, the higher available, at the lowest possible voltage as opposed to having multiple frequencies at the same voltage and constantly having to switch between them (which uses even more clock cycles)?

The only time it makes sense to have multiple frequencies is when your highest frequency is not capable of running at your lowest voltage... But with the MBA that is not the case as the 11.6" MBA can run at .875v at 1.6Ghz/1.4Ghz all day long.

When ive done some quick comperations between using only 1.4ghz at lowest voltage, and using only 600mhz at the lowest settings, ive seen clearly that the 1,4ghz single setting is draining battery a lot more.

There has to be something more to the b/2 settings, like slowing down buss speeds etc.

 

[omniatlas]

When ive done some quick comperations between using only 1.4ghz at lowest voltage, and using only 600mhz at the lowest settings, ive seen clearly that the 1,4ghz single setting is draining battery a lot more.

I've set it up so the default frequencies are all at 0.875. Would it be wise to just have one setting, 1.6 mhz at 0.875? I heard B/2 shouldn't be enabled on the 11".

Suggestions please, thanks.

 

[aleni]

I've set it up so the default frequencies are all at 0.875. Would it be wise to just have one setting, 1.6 mhz at 0.875? I heard B/2 shouldn't be enabled on the 11".

Suggestions please, thanks.

i decided to use single 1.4ghz setting on my base 11" at 0.875v.

it feels more responsive withno significant battery loss.

 

[wressus]

i decided to use single 1.4ghz setting on my base 11" at 0.875v.

it feels more responsive withno significant battery loss.

So you have a 1.4Ghz, and can choose 0.875v?? What settings are you able to choose? I ca n only alter the 1.4Ghz setting to 0.9v

 

[aleni]

So you have a 1.4Ghz, and can choose 0.875v?? What settings are you able to choose? I ca n only alter the 1.4Ghz setting to 0.9v

the minimum setting for 1.4ghz that i can use is 0.875v.

 

[omniatlas]

the minimum setting for 1.4ghz that i can use is 0.875v.

How about if you have the 1.6 ghz macbook air? I don't want to loose performance with lower hz settings. I e-mailed magnus and this is what he had to say in response:

--
Hi xxx,

Yes. At least for adapter.
It depends on the work you are doing while running on battery, if you benefit from lower frequencies.

/Magnus

--

But I don't want to use lower frequencies? Is it okay just to have 1.6 ghz at 0.875 volts with no other settings?

 

[aleni]

How about if you have the 1.6 ghz macbook air? I don't want to loose performance with lower hz settings. I e-mailed magnus and this is what he had to say in response:

--
Hi xxx,

Yes. At least for adapter.
It depends on the work you are doing while running on battery, if you benefit from lower frequencies.

/Magnus

--

But I don't want to use lower frequencies? Is it okay just to have 1.6 ghz at 0.875 volts with no other settings?

it depends.. when i use my air, i alwaya use it and almost never idling it. when im done using it, i closed the lid. tasks sewm more responsive and finish faster with single setting.


if u do alot of idling, like let your air running itunes while you are sleeping, it's better to mix with lower frequencies as well, because it's useless for it tobe running at 1.6ghz all the time just to play songs via itunes. so it all depends on your usage. u might as well keep 1.4ghz and 1.6ghz only and kick the others like 800mhz and 1.2ghz out if you want performance with no dramatically battery loss.