maemo.org - Talk - Overclock the N900?

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- - Overclock the N900? (https://talk.maemo.org/showthread.php?t=39753)

Re: Overclock the N900?

Igor explains why overclocking is dangerous and its harm cannot be easily detected
http://lists.maemo.org/pipermail/mae...ry/024208.html

Re: Overclock the N900?

Wheheyy 900 posts :P

Re: Overclock the N900?

@Javispedro

Manufacturers set everything to lowest usable speeds because they are overcautious. My very old N95 has all electronics in great state but everything else(plastics, screen etc) is just in agonal state so I wouldn't mind if they made its processor twice as fast with half of lifespan if it would still last longer than phone itself. Anyway, people know the risks of overclocking their N900's so let them be happy as not everybody want to have one device for more than 2-3 years anyway.

Re: Overclock the N900?

From Igor Stoppa, the engineer who gave the warning.

Quote:

Originally Posted by Igor Stoppa

Hi,
the damage is not directly related to the temperature, but rather to the overvoltage used @600MHz.

There are few temperature sensors, but not all of them are accessible to the normal SW and most are just thermal shutdown safeguards.

But the battery, for example, has a temperature sensor nearby.

However please notice that usually their readings are meaningless apart from indicating the _local_ temperature, since there are so many heat sources on the board.

Finally, being the device basically plastic, not perceiving high temperature at surface level is not so relevant, since plastic is not such a good thermal conductor and allows for higher and longer power peaks. Phones with metallic casing have lower max temperature allowed at surface level because of the higher transfer efficiency (the delta being 15C, on top of my head).

Cheers, Igor

Takeaway messages:

Don't use temperature sensor readings as a guide to what is or is not going to damage the system
The N900 can not be expected to handle sustained overclocked heat production as well as a phone using metallic casing. More generally: device heat sinking is an important parameter.
The operational voltage (as was stated by Matan) is the main reason for the decreased lifetime when running at top frequencies.

What's not directly included in that short message, but is known for modern CPUs, is that operating at elevated temperatures accelerates the process known as electromigration, which eventually leads to a short or other fault in the processor. It's a cumulative effect, so e.g. if the CPU is at 40C and top voltage for 1 hour, the decrease in lifetime could be equivalent to 100 hours at 30C and bottom voltage. It's a consequence of the exponential dependence on temperature of the relevant physical processes.

Realistically, if you are going to throw away your N900 in a year or even two, overclocking the top speed step to 800 MHz and using it normally is probably not going to be a problem.

Edit: oops Titan beat me to the link. ;)

Re: Overclock the N900?

Quote:

Originally Posted by casper27 (Post 596128)

had mine on 900/125 for 12 hours now all gravy so far.
One thing though in conky it never seems to drop below 500mhz even with 2 percent usage.

plugged in via usb maybe? ;0)

Re: Overclock the N900?

Quote:

Originally Posted by bartekxyz (Post 596130)

"With the ability to scale in speed from 600MHz to greater than 1GHz, the Cortex-A8 processor can meet the requirements for power-optimized mobile devices"

Source: http://www.arm.com/products/processo.../cortex-a8.php

It was said hundret times that Cortex A8 was made with great scalability of speed in mind. Long live OCed N900's :)

That's not a valid argument thought. Like Javis said Cortex-A8 isn't really anything physical.
Samsung got official 1ghz processor(45nm) called hummingbird that uses Cortex-A8 arch where first phone is released in months time, but it's 45nm and doesn't share much with the N900 while it's running 600mhz Cortex-A8.

For me this overclocking is great. I buy new phone every year for certain and i'm not planning on selling N900 so i'm really happy with the 900mhz overclock.

Re: Overclock the N900?

i've just flashed mine with the 800mhz 125 idle and its running fine, actually, the change is amazing.

everything feels much smoother, i am able to stream bbc iplayer perfectly over my 3g connection, which i never could before, youtube tv shows now works very well, and overall it just feels much smoother.

i'm gonna be keeping an eye on it over the next few days, if it starts to play up i'll flash it back, but right now impressions are pretty good to be fair.

great work and massive thumbs up to everyone involved!

Re: Overclock the N900?

Quote:

Originally Posted by javispedro (Post 596100)

Yes, that's why I spent a few minutes googling for the quote :)

But what are all those people going to do? Keep it idle? No, they're going to play pcsx4all which will lock it at whatever the maximum frequency is.
The expected lifetimes are unfortunately not public AFAIK.

I'm not planning to play pcsx4all, and I doubt that "all those people" are either.

I think you don't understand "all those people" very well. They just did Nokia a big favor by getting good publicity at a time when most publicity isn't going to Nokia.

Re: Overclock the N900?

Quote:

Originally Posted by baron von bubba (Post 596151)

plugged in via usb maybe? ;0)

You know the simple things in life :)
Don't know how I missed that one, just charging and forgot the usb was in. Cheers

Re: Overclock the N900?

I always appreciate caution, but unless Nokia got a special 3430 chipset that is "weaker" than the ones in the Archos 5 and Sammy / Motorola phones, 800mhz is well within the operational ceiling of the chipset.

The one caveat is if the cooling solution in the N900 is weaker than those units, but I notice zero temperature difference between 800mhz and 600mhz. I also have not noticed the battery to be draining any quicker, based on my normal use. I DO notice that the N900 performs very smoothly now, for everything to do with the phone. I could not say that before. The N900 is now just as smooth as the Droid (which is also at 800mhz max scale).

Kind of like (in a loose way) the SU7300 Intel chip. Stock is 1.3ghz, but ASUS and Dell both ship at 1.73ghz. I luv my M11X- almost as much as the N900 :)

Hillbilly summary:

The N900 now performs smooth like I expected it too in November. My favorite apps (MAME and PSX4ALL) both play much better, as well as video and Flash content. So much so, I suggest the 600mhz is too weak for the design and function of the device (it is smooth now, but was not prior to OC).