The Arm Cortex A8...

[jlepley]

One of the repeated points I've heard with the Pandora's processor is that it runs standard at 600MHz, and can be overclocked up to around 900MHz. However, I decided to look up the processor, and it's official website says:

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 needing operation in less than 300mW; and performance-optimized consumer applications requiring 2000 Dhrystone MIPS. [emphasis mine]

I'm not sure what to make of this. Has the Pandora Team been understating the potential of the processor or can the Pandora just not run it at the advertised speed for any particular reason?

 

[Pickle]

One of the repeated points I've heard with the Pandora's processor is that it runs standard at 600MHz, and can be overclocked up to around 900MHz. However, I decided to look up the processor, and it's official website says:

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 needing operation in less than 300mW; and performance-optimized consumer applications requiring 2000 Dhrystone MIPS. [emphasis mine]

I'm not sure what to make of this. Has the Pandora Team been understating the potential of the processor or can the Pandora just not run it at the advertised speed for any particular reason?

This is a repeat thread, so try searching. This has been discussed.
The boards as they are with the voltage supplied to the cpu are peaking at 900 Mhz. Ive only gotten to 850 stable.
But Weston has stated that with a voltage increase higher freq's may be possible. The negatives of course are lower battery duration and cpu life.

 

[Ribreaper]

Maybe heat becomes an issue?
I read something about it running very cool stock, I am not very good with these ARM processors. (yet).
Also the iPhone3GS has the same processor right? Just asking since there is rumors going around saying the 3GS overheats easily.
Although the iPhone is alot smaller and more crammed than the Pandora so heat shouldnt be that much of a problem I think.

Well, my guess is that they said up to 900Mhz as they didnt think more was needed.
I dont recall anyone claiming that it was the maximum clockspeed.

EDIT:: Hehe, guess Pickle nailed it for you.

 

[Pickle]

Maybe heat becomes an issue?
I read something about it running very cool stock, I am not very good with these ARM processors. (yet).
Also the iPhone3GS has the same processor right? Just asking since there is rumors going around saying the 3GS overheats easily.
Although the iPhone is alot smaller and more crammed than the Pandora so heat shouldnt be that much of a problem I think.

Well, my guess is that they said up to 900Mhz as they didnt think more was needed.
I dont recall anyone claiming that it was the maximum clockspeed.

EDIT:: Hehe, guess Pickle nailed it for you.

ARM arnt known for getting hot. I suspect it would be more from the battery.

 

[Adventus]

Also, I'm pretty sure the 1Ghz chips are with a different manufacturing process.

Maybe heat becomes an issue?

Heat is rarely a problem with ARM devices. Its more likely clock skew / timing delays causing components to get out of sync.

 

[anexanhume]

Taken directly from ARM's A8 page:

The 65nm (LP) dynamic power measured is at 1.2 V nominal and hence is higher than the 65nm(GP) dynamic power which is at 1.0V. However, the 65nm (LP) leakage is significantly lower and this is the major consideration for mobile or battery operated devices which need to conserve power in standby mode.

The GP part is a higher leakage part, but is capable of higher clocking. This is well known in overclocking circles too; higher leakage parts are better for overclocking.

http://arm.com/products/CPUs/ARM_Cortex-A8.html

 

[Squidge]

Don't forget that the Cortex comes in many versions, and is only one part of the silicon of the OMAP the Pandora uses. Voltage can be software controlled (to a degree), but don't expect 1Ghz or higher. 800Mhz is pushing it at standard voltage.

 

[torpor]

.. and anyway, 800mhz is *plenty* fast.

 

[GuchaRU]

personally I don't want to burn my pandora, so I am hardly gonna change default voltage.
maybe only when I need to play Dreamcast or N64 if this emulators come to playable state.

 

[atomicthumbs]

There are different models of Cortex-A8. The one built into the main chip in the Pandora does 600 by default.

 

[darkborn]

I hope that Pandora version of Angstrom will remain easy-changing of frequency as it is done at e.g. Zire72. (when you need speed <> more battery duration)

 

[Pickle]

I hope that Pandora version of Angstrom will remain easy-changing of frequency as it is done at e.g. Zire72. (when you need speed <> more battery duration)

It's simple:
echo <freq> > /proc/pandora/cpu_mhz_max
example: echo 600 > /proc/pandora/cpu_mhz_max

 

[WizardStan]

echo 9000 > /proc/pandora/cpu_mhz_max
There, problem solved. Maybe now nobody will complain about it being too slow

 

[elwing]

One of the repeated points I've heard with the Pandora's processor is that it runs standard at 600MHz, and can be overclocked up to around 900MHz. However, I decided to look up the processor, and it's official website says:

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 needing operation in less than 300mW; and performance-optimized consumer applications requiring 2000 Dhrystone MIPS. [emphasis mine]

I'm not sure what to make of this. Has the Pandora Team been understating the potential of the processor or can the Pandora just not run it at the advertised speed for any particular reason?

the Cortex A8 is a processor core design that is sold to compagny that actually build processor and SoC using this ARM core design, the cortex A8 design could run higher than 1GHz, but the actual implementation that the OMAP3 use can only run at 600MHz without being overclocked. that's how I understood it at least...

 

[Enverex]

echo 9000 > /proc/pandora/cpu_mhz_max
There, problem solved. Maybe now nobody will complain about it being too slow

"Hey Vegeta, what does the distro say about its power level?"

 

[hlidegp2x]

echo 9000 > /proc/pandora/cpu_mhz_max
There, problem solved. Maybe now nobody will complain about it being too slow

9 GHz !? that's an awesome beast that pandora

 

[Luftwaffles]

"Hey Vegeta, what does the distro say about its power level?"

I believe its over 9000.

 

[limestrael]

So, in brief, we will be able to boost it up to 800 MHz without damages?

 

[fiveseven]

I believe the maximum *stable* overclock will vary between units. Some could do 800mhz/900mhz/9000mhz, but I wouldn't guarantee it.
I remember my gp2x being 200mhz by default, but reaching 260 as it's upper limit. There were, however, reports of some units going higher (300mhz in rare cases I think).

Bottom line: Estimates on how far a Pandora can be overclocked are *probably* not going to be all that accurate, as the figure is probably going to change from unit to unit.

 

[Pleng]

I believe the maximum *stable* overclock will vary between units. Some could do 800mhz/900mhz/9000mhz, but I wouldn't guarantee it.
I remember my gp2x being 200mhz by default, but reaching 260 as it's upper limit. There were, however, reports of some units going higher (300mhz in rare cases I think).

My GP2x never got above 220

I'll bet if somebody manages to overclock to 9000mhz, though, that unit will fetch a fair sum on ebay! I wonder what it would do to battery life though?