pizzaboy150
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Pi 2 1.2 to 1.6Ghz

Sat Apr 16, 2016 8:26 am

So been having a look at some of the chips on the Pi2 and there features and stumbled across the Arm website. Was initially looking at some of there high end processors and wondering how easy it would be to buy a better chip and whether it would work?

Anyways look at the spec of the Cortex-A7 series it states;
In a 28nm process, the Cortex-A7 can run at 1.2-1.6GHz, has an area of 0.45mm2 (with Floating-Point Unit, NEON and a 32KB L1 cache) and requires less than 100mW of total power in typical conditions. This lowest performance profile makes it an ideal standalone processor for a range of mobile devices, and means the Cortex-A7 can ultimately deliver similar performance to the Cortex-A9 processor at much higher levels of power efficiency.
So I have overclocked mine to 1Ghz why cant the pi reach 1.2 to 1.6?

Just curious really?

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rpdom
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Re: Pi 2 1.2 to 1.6Ghz

Sat Apr 16, 2016 8:42 am

pizzaboy150 wrote:Anyways look at the spec of the Cortex-A7 series it states;
In a 28nm process, the Cortex-A7 can run at 1.2-1.6GHz,
So I have overclocked mine to 1Ghz why cant the pi reach 1.2 to 1.6?
I've highlighted the important bit of that spec.

The Pi uses a 40nm process. The costs of redesigning the whole chip to use a smaller scan would be too high.

ghans
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Re: Pi 2 1.2 to 1.6Ghz

Sat Apr 16, 2016 8:44 am

ARM doesn't make chips. They sell chip designs.

So they can't know if a particular chip can be overclocked
or not. Furthermore overclocking is a gamble by nature ,
some chips are very overclockable some or not. Even
chips from the same batch. Read up on this here :

https://en.wikipedia.org/wiki/Product_binning

ghans
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fruitoftheloom
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Re: Pi 2 1.2 to 1.6Ghz

Sat Apr 16, 2016 9:14 am

pizzaboy150 wrote: how easy it would be to buy a better chip and whether it would work?
The ARM CPU is not replacable, it is manufactured in the BCM2836 SoC:

https://en.wikipedia.org/wiki/System_on_a_chip

https://en.wikipedia.org/wiki/Raspberry_Pi
Retired disgracefully.....

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DougieLawson
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Re: Pi 2 1.2 to 1.6Ghz

Sat Apr 16, 2016 11:22 am

pizzaboy150 wrote: how easy it would be to buy a better chip and whether it would work?
I can find you one for $35, no hardware modifications needed. It's 100% guaranteed to work about six times faster than your RPi2.

http://uk.rs-online.com/web/p/processor ... s/8968660/

You may need to rewrite some stuff on your SDCard to get it running.
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pizzaboy150
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Joined: Sat Sep 05, 2015 11:03 am

Re: Pi 2 1.2 to 1.6Ghz

Sat Apr 16, 2016 12:05 pm

Thanks for the feedback guys, makes a lot of sense didn't think of it being an arm inside a bcm! And also didn't realize it was 40nm construction!

Thanks

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