CPU Boost Counter

[(V)3@7Y]

In a recent build, i have noticed that there is no limit on the CPU Boost counter, or at least it goes further than i am willing to take it. Basically i would like to know how high it can be taken before horrible things start to happen inside my DAP. Obviously battery usage will go up, but is there any chance that my CPU will destroy itself?

[Multiplex]

I think that this is a count of the processes/tasks that have requested to boost the CPU - as long as the counter is greater than zero the CPU is boosted, if it is zero the CPU is low speed.

You don't make it go faster by incrementing the count (you just make it stay at the high speed).

Or maybe it has been totally re-architected since I last looked into that area.

[(V)3@7Y]

hmmm... i never though of it this way.
Preceeding the increase of the "boost counter" frequency increases, i.e.;
24000Mhz
30000Mhz
80000Mhz
boost 1
2
3
4
etc.

Which makes me wonder if  perhaps it is, as you say, making it stay at a higher speed,
(but with an increment of say 50 is it boosting the CPU as if there were 50 tasks?)
Im not sure... Unless i'm imagining things, things do run faster with a higher boost counter value
i.e, I can decode music and run for example the "plasma" plugin with a much higher frame rate than without

Maybe its just wishful thinking?

[GodEater]

Or maybe it has been totally re-architected since I last looked into that area.

Nope - you're right on the money with your explanation - that's exactly what it does.

[(V)3@7Y]

OK, with this in mind, is there... a safety level, originally, the maximum you could manually alter it to is 4.
Which makes me wonder if that was so for a reason. Surely there is a practical limit to high how it can go, otherwise it would have been like this the whole time.

[saratoga]

OK, with this in mind, is there... a safety level, originally, the maximum you could manually alter it to is 4.
Which makes me wonder if that was so for a reason. Surely there is a practical limit to high how it can go, otherwise it would have been like this the whole time.

Putting it higher just boosts the CPU.  This wastes power so its not like that by default. 

[(V)3@7Y]

of course, power usage would be an issue, but that doesn't worry me so much as the thought that all of that energy has to go some place, and its most likely going to be heat. is there currently a maximum value? or is it infinite?
Surely your going to hit a point where things start getting hot?
Im quite fond of my MP3 player and i dont really want it to turn into a blob of molten silicon!
I do think you've missed my point a little... on older builds, there was no possible way of exceeding 4, in the later builds, it will go over 50 (Manually) i dont think it will exceed 4 by default
This is a substantial increase, surely there will be irrepairable side effects?

[saratoga]

of course, power usage would be an issue, but that doesn't worry me so much as the thought that all of that energy has to go some place, and its most likely going to be heat. is there currently a maximum value? or is it infinite?

Well the boost counter is probably a 32 bit signed int, so 2^31-1 would be its max value.  For boosting itself, its a binary value, so the highest would be "on".

Surely your going to hit a point where things start getting hot?

I think the difference between boosted and unboosted is about 65 mW, so you're unlikely to notice a difference in heat.

This is a substantial increase, surely there will be irrepairable side effects?

More likely someone just changed the GUI control for that screen.

[(V)3@7Y]

well put, i think that has covered everything i need to know.
If there is a fire inside my DAP I shall be consulting you

Thanks for everybodies input, it has been an enlightening experience

(V)347Y

[Llorean]

The player automatically boosts quite regularly anyway, and there's only two states, "Boosted" and "Unboosted" (well, there's also "Idle" I suppose). Setting the counter to any number that is not 0 makes it "Boosted" all the time. This is pretty much pointless, because the only time it should be "Unboosted" is when it doesn't need "Boosted." Now you're making it skip ever being "Unboosted."

[Big D]

I'm a bit confused. What exactly does this boost thing do?

Thanks.

[Llorean]

Okay:

Normally we run the CPU relatively slowly, to save battery. Some things this will be too slow for (for example, decoding music) so we run the CPU at its full speed (the fastest speed it's designed to safely  be run constantly at) for periods until all the work is caught up, and we get a little bit ahead (at least with music), then we slow it down to the slow speed again.

So this fast speed is called "boosted." We automatically go there when work needs to be done, then come back after. Setting the boost counter higher just means the CPU is always at "boosted." There's no real reason to do this other than a desire to drain your battery more quickly.

[robin0800]

There's no real reason to do this other than a desire to drain your battery more quickly

Why have it user adjustable at all?

[Llorean]

You may notice it's in the Debug menu. The one that says "Keep Out". The one that's for Developers to tinker and test things? I think it should be rather obvious that it's not intended for common user adjustment...

[(V)3@7Y]

Applications run a little faster while decoding music if it is "maxed out"
which brings me to a hypothetical question; if i happened to possess an old ipod or other DAP running rockbox, and i was wanting to boost the CPU to a much higher level (for whatever purpose), regardless of potential damage to the inner workings, how could i disable the limit on over clocking it? I have no real experience in compiling builds, but if it were simple enough, i would like to remove this. Just a thought... all be it destructive.