Overclock speeds?


Blue Protoman

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I heard that some units can only go to 850Mhz, while some can go all the way to 1Ghz. All units are not created equal; I do know that the highest clock speed guaranteed is 800Mhz. What happens if you overclock too much, does it reduce your Pandora's life, etc. All I know is that overclocking drains your battery quicker. Someone mind explaining to me this whole thing in more detail?


Also, if you overclock in Ginge (say, boosting a game in Final Burn Alpha), does that throw a wrench into things, what with the default being different?
 
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WizardStan

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I do know that the highest clock speed guaranteed is 800Mhz.
The highest clock speed guaranteed at stock voltage is 500Mhz. It is guaranteed to 600Mhz in so called "overdrive" mode, which increases the voltage. Anything above 600 is icing on the cake. Most people have been able to clock stably to 800Mhz in stock voltage though, and beyond 900 and 1000 in overdrive mode, but they should consider themselves lucky, because you never know what the future will bring. That's why I keep mine clocked to 500 or lower unless I actually need it, so I don't get used to the idea of always having more speed.

What happens if you overclock too much, does it reduce your Pandora's life, etc. All I know is that overclocking drains your battery quicker. Someone mind explaining to me this whole thing in more detail?
At stock voltage, 500Mhz, the OMAP chip is estimated to last about 20 years of constant use. In overdrive mode at 600Mhz, it is estimated to last only about 5 years. There are no estimates for the 800 and 1000Mhz that some people are running at because TI doesn't endorse those speeds. They may work just fine now, they may burn out after 2 or 3 years, they might last forever, we don't know.


It also drains your battery much faster, as you say.

Also, if you overclock in Ginge (say, boosting a game in Final Burn Alpha), does that throw a wrench into things, what with the default being different?
It runs just fine, usually better for the added speed boost
 

gadgetoid

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This discussion was fairly pervasive in the world of the N900. One should expect similar results from the Pandora.


The big (in the long term, anyway) problem with over-clocking, as I understand it, is even when your overclock is "stable" you are actually wearing down the CPU more quickly as the increased flow of electronics literally erodes the CPU away... as far as I understand it, anyway.


A lot of effort (or at least some effort) goes into optimising Pandora software to work well at 500mhz, so the need to overclock should be minimal. Maintaining speeds of 1Ghz+ is, if nothing else, reckless.


I suppose it depends how much you hate Frameskip ;)


I think 850mhz was pretty much the magic number for the Nokia N900, perhaps this will apply to the Pandora. There aren't really enough in the wild to tell, yet. Some sort of CPU monitoring and speed-step solution would be nice, if it's possible and not already available. The last I heard, PNDs could include a clockspeed setting- but I don't know if that went anywhere.


Software that at least notifies you that it runs best with a bump to XYZmhz would be better than running at a constant 800+, and better than forgetting to overclock before you launch certain software.
 

Blue Protoman

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I'm not going to constantly overclock. Might do so while playing N64 and arcade games, but...
 

WizardStan

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The last I heard, PNDs could include a clockspeed setting- but I don't know if that went anywhere.
That already happens. PNDs that specify a clock speed pop up an option when you run them of setting the clock speed or keeping the current speed, and remembering your choice for next time or not.


If you allow the change, it resets it back to what it was after the program quits.
 
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Prometheus

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Mine can do 850MHz at the stock voltage, if necessary (I know of a couple out there that can do 900MHz at the stock voltage - I think skeezix and Dunny have mentioned it? I could be wrong, though). I've never changed the voltage, and don't intend to, and most things I do don't really need more than the standard 500MHz or 600MHz. :p
 

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Mine does 810ish at stock voltage, and as I got very little advantage in going from opp4 to opp5 (the max safe value). I was also able to run quite high at opp1 (the lowest, which is speced to only run up to 125MHz). So far as I could tell, there wasn't a significant change in battery drain for a fixed workload at different opp/maxclk rates (makes some sense since the actual cpu speed is dynamically adaptive, and the settings are the high limits only). There is a bit of info on the wiki talk page for power modes. More data points for power on the wiki would help.
 

ZXDunny

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Mine can do 850MHz at the stock voltage, if necessary (I know of a couple out there that can do 900MHz at the stock voltage - I think skeezix and Dunny have mentioned it? I could be wrong, though).

I use 900 for MAME - Outrun plays *so* sweet at that speed. It's rock-solid as far as I can tell, but of course the o/c app doesn't let you go higher than 900. I'd kind of like to see what happens when I shift up to 1GHz in the default voltage, if only for a few mins :)


D.
 

WizardStan

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On their website they changed the specs to:

Up to 720-MHz ARM Cortex™-A8 Core

So I guess this is what they can "guarantee"?
That's actually a different part number. It applies to new chips coming out of the process for those that have paid for that extra guarantee. Old chips aren't automatically bumped to the new spec, and it's still possible to buy their 600Mhz rated chips being produced new.
 

WizardStan

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I use 900 for MAME - Outrun plays *so* sweet at that speed. It's rock-solid as far as I can tell, but of course the o/c app doesn't let you go higher than 900. I'd kind of like to see what happens when I shift up to 1GHz in the default voltage, if only for a few mins :)
Edit the file /usr/pandora/scripts/op_cpuspeed.sh and change the maxmhz value to whatever you want.


OPT does not condone this behavior and flying purple monkeys may explode from your Pandora if you set it above the safe clock speed. Or it might just crash and force you to pull the battery for a minute.
 

Elanzer

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I have run my N900 at 1.3ghz without issue, but that was at maximum selectable voltage. For everyday use, I run at 1ghz with below stock voltage, with battery life better than stock.


It's probably possible for someone with a lucky Pandora to hit this, given proper voltage selection options.
 
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Cameleon

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Mine can go up to 875 MHz but I've never really found a reason to clock it that high other than curiosity when I first got the device. I have found that some SNES games still slow down well over 700 MHz, like Megaman X3 (Toxic Seahorse's stage) but I've been reluctant to overclock too high.
 

craigix

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Mine can go up to 875 MHz but I've never really found a reason to clock it that high other than curiosity when I first got the device. I have found that some SNES games still slow down well over 700 MHz, like Megaman X3 (Toxic Seahorse's stage) but I've been reluctant to overclock too high.

Maybe it slowed down on real hardware too? You won't stop it if that was the case.


d: For outrun, are you using Cyclone 68k cores? It should not need 900mhz! That's slightly crazy.
 

ZXDunny

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Maybe it slowed down on real hardware too? You won't stop it if that was the case.


d: For outrun, are you using Cyclone 68k cores? It should not need 900mhz! That's slightly crazy.

Oh yes, I was just testing at high speed. I've since managed to get it running acceptably at 600mhz by playing with the Mame4All settings :)


Loving this thing, beats the '2x hands down!


D.
 

Cameleon

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If anyone wants me to check this, I can probably set up my (NTSC) SNES later to do so. :p


No real need, thanks anyway. Although you probably could answer a quick question for me...Any rough pointers on how to beat Bit? I run into him on Crush Crawfish's stage and he kicks my ass every time.
 

Prometheus

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^ Alas, none to give, sorry. X3 is one of my more recent acquisitions, being the pain to get hold of that it is.
 

sporkbox

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No real need, thanks anyway. Although you probably could answer a quick question for me...Any rough pointers on how to beat Bit? I run into him on Crush Crawfish's stage and he kicks my ass every time.

His general pattern is a screen-high jump up, then he falls to your level and dashes with his sword out. Climb the wall and drop when he dashes over. Your buster should be charged by now, so blast him. He'll do this 2-4 times before sitting still and firing a few homing fireballs. He may also throw stun rings that will force X to the ground. You'll have to button mash to get out of those quickly. After throwing the fireballs and/or the stun rings, he'll repeat his pattern. I forgot what his weakness was... Byte's is either acid or the drill, though.
 

MarioPandio

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Well I can stably play Tekken 3 at 1025mhz which ups the fps to 35-40fps from 25-30fps at 800mhz but its not desired to run that high and certainly with further notaz magic I can see that not being required. Kind of a battery killer if not more and in no way guaranteed to continue in that manner.
 
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