Easy Overclocking


Vimacs posted on Apr 26 2005 at 09:41 PM said:
why are you doing this *** when you can solder? go the real(and secure) way.

Of course it's a temporary solution - my soldering iron has a 3mm tip, so it's too big to solder such small components to the board. I'll get my hands on a smaller one soon and sort it permanently.
 
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Possible interesting find that maybe backs up my theory about regular 1.5v alkaline batteries allowing more OC'ing than 1.2v NiMh batteries.

Last night at work, when I posted my last post about the batteries dying, I had a friend pick me up some Energizer's.... with those I fiddled around with the resistors and after much fiddling got it to where it clocked 192mhz stably, and I ran it that way for a good 30 mins to be sure and it worked like a champ.

When I got it home I swapped the energizer alkalines back out for my 230mAh 1.2v rechargeables. Later that day I was playing and I started getting lockups at 192mhz. So I tried 188, then 184, then all the way down to 166mhz, just letting the system run (DrMD running Sonic 2) and at each setting it would eventually lock up, within 2-10 mins. Without changing anything from the night before other than the batteries.

Not proof, I know, but convincing evidence.

Anyways, I'm at work fiddling with it again tonite with the rechargeables now, starting from scratch... I'm so pissed... was working so perfectly at 180mhz til I messed with it.....


EDIT: FOUR FRICKING HOURS LATER and I'm still messing with it, adding lead, removing lead... and I can't get it to do 184mhz stably again... longest it went was 15 mins before locking. I'm.... so.... pissed
 
SIX AND A HALF FRICKIN HOURS LATER... and I still can't seem to get it right. It's so weird... before, when my GP was bone stock, running DrMD, it would run up to 164mhz seemingly indefinately (well until my batteries ran out). At 168mhz, it would lock within seconds of gameplay, and at 172mhz, it would lock the second I exited the menu. Now tonite, I've done and redone and redone this pencil mod dozens of times... testing and testing. I've gotten all kinds of different results, from no apparent effect, to it not even wanting to boot the Gp32 logo.

The odd thing is though... that even when I get it to OC to really high numbers and not lock instantly or very quickly after exiting the menu back to the game... like quite a few times I got it to where I could push to 220mhz and exit and the game would play for at least a minute... other times I had it to where it would only OC to high 180-low 190mhz before it would lock immediately after exiting the menu. But no matter how high it OC's before just instantly locking, I can NOT get it to run stably for a long period of time, except in Castlevania :(

Sonic 2... will only run on average 3-5 mins before locking up

Sonic 3... ran about 15 mins before locking up

Castlevania will run to 30 mins before I just turn it off

I just don't get it... how is it I can clock sooooo high... 220mhz and it will run for at least a minute... yet even at 180mhz it still locks up in some games after only a couple minutes?? That doesn't make sense... I thought maybe too much voltage... over heating, but again, even when I dropped the voltage way down, to where it wouldn't even let me select 184mhz w/o locking instantly, and then tried to run sonic 2 at 166mhz and it still locked within minutes... I dont' get it.

Any tips? I'm about to just put the thing back to stock :( :( :(
 
bast525, just bite the bullet and "properly" voltage mod your GP32. You obviously loving the higher cpu speeds, shell out a couple of pounds for a couple of resistors and get soldering. I did mine and have never looked back.
 
bast525 posted on Apr 27 2005 at 11:36 AM said:
Any tips? I'm about to just put the thing back to stock :( :( :(

Maybe this is the only method to show the people the consequences of overvolting a cpu and what electromigration does. First becomes unstable at higher clocks, no matter the voltage used; more voltage, more deterioration. If voltage is not reduced, the cpu will become unstable even at officially supported clock rates.

Good luck.
 
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bast525 posted on Apr 27 2005 at 04:36 AM said:
SIX AND A HALF FRICKIN HOURS LATER... and I still can't seem to get it right. It's so weird... before, when my GP was bone stock, running DrMD, it would run up to 164mhz seemingly indefinately (well until my batteries ran out). At 168mhz, it would lock within seconds of gameplay, and at 172mhz, it would lock the second I exited the menu. Now tonite, I've done and redone and redone this pencil mod dozens of times... testing and testing. I've gotten all kinds of different results, from no apparent effect, to it not even wanting to boot the Gp32 logo.

The odd thing is though... that even when I get it to OC to really high numbers and not lock instantly or very quickly after exiting the menu back to the game... like quite a few times I got it to where I could push to 220mhz and exit and the game would play for at least a minute... other times I had it to where it would only OC to high 180-low 190mhz before it would lock immediately after exiting the menu. But no matter how high it OC's before just instantly locking, I can NOT get it to run stably for a long period of time, except in Castlevania :(

Sonic 2... will only run on average 3-5 mins before locking up

Sonic 3... ran about 15 mins before locking up

Castlevania will run to 30 mins before I just turn it off

I just don't get it... how is it I can clock sooooo high... 220mhz and it will run for at least a minute... yet even at 180mhz it still locks up in some games after only a couple minutes?? That doesn't make sense... I thought maybe too much voltage... over heating, but again, even when I dropped the voltage way down, to where it wouldn't even let me select 184mhz w/o locking instantly, and then tried to run sonic 2 at 166mhz and it still locked within minutes... I dont' get it.

Any tips? I'm about to just put the thing back to stock :( :( :(

Most likely that you have some residue on the sides of the resistor that have not been completely removed. Try using a small thin peice of an eraser to clean the resistors around the sides, tops, etc. and start again. Alsomake absolutely sure that you have not mistakenly put graphite on some other resistor. It's an easy mistake to make.
 
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For what its worth mine is still working fine at 180, showing no signes of any problems, been what 2 weeks now? Think I was one of the 1st to try this.

I think the key is to not be too greedy, if it works the 1st time but you only get an extra 20mhz then be happy with it... Cant be good to keep applying and removing etc.

As reesy says if your going to put that ammount of time into it you may as well have the real resistor mod done.

Steve.
 
Well, The first time i tried this and after using my GP for a while, I found that once i`d clocked it too high via any program and it would lock up, I would have to wait a while before i could use it again (the screen wouldn`t power on, The red light would glow though). When it did eventually power on, It would randomly display horizontal lines across the screen or show corrupt graphics etc, Then eventually it would lock up again, But sometimes it would work perfectly, Until i switched it off and back on again.

This was really getting to me. So i used windowleen (window cleaner with vinegar in it) and a soft cloth to remove all traces of the graphite and left it to dry for a couple of minutes. I then tested it at its guaranteed speed of 166mhz in various programs to see if all was well, I did test for quite a while and all was good.

I then proceeded to try the mod again, But this time do it properly, ie not be so generous with the graphite this time. I used the same pencil i used before, Which is a cheap unmarked pencil with a medium soft, medium dark lead in it.

It took me nearly an hour to get i right, But basically i first put one, then two lines of pencil on the r52 resistor. The GP would lock up at pretty much anything above 166mhz. I then applied one, Then two lines of graphite to the r48 resistor (testing in between each) and Bang, It works all the way up to 208mhz, But locks up at 212mhz. I`ve decided to keep it at a happy medium and not go above 200mhz, Which i am happy with. I did a test (detailed further back in this thread) and she lasted 48 hours non stop without a hitch at 200mhz running thunder force 3 via DrMD, And she`s still going strong.

This mod is probably not for everyone as there is a lot of luck involved in getting it right. It hasn`t killed anyone`s GP yet, And there is no guarantee how long a GP will last with this mod applied. I don`t own the necessary equipment or have the soldering skills to do the mod the proper way, And as i have said on a few occasions, I own more than one GP and so am willing to take the risk.

Disclaimer: No GP was harmed or GP`s safety was at risk while performing the above mod. :p

Your Mileage May Vary.

EDIT: General tidy up.

Trooper
 
Update time :D

This is gonna be a VERY long one, three days of fiddling and testing and non posting all coming out in one post here :) You have been warned.

Again, I seem to have found some interesting patterns which I think are giving some small bit more info on how this works, how it doesn't work, etc. in the case of my GP at least.


Okay, first I want to point out, again, that the first time I did this, I was doing all my testing with Castlevania... but I wasn't actually PLAYING anything, just testing (too excited to settle down and play for more than a few minutes of anything at a time). Only after a few days did I go back to just playing games normally, and that's when I noticed it would lock up on Sonic 2 within minutes. After trying a lot of different combinations of putting different levels of graphite on both resistors and then doing all my testing with Sonic 2... trying to get it to be stable at around 192mhz or above, nothing seemed to work... 10 mins tops before it would lock up. But then, going back to test with Castlevania, I'd still get 30 mins before just shutting it off myself. At the same settings that I was having problems with Sonic 2, Castlevania would never seem to lock up. So discovery #1 for me is, for whatever reason, Castlevania runs more stably with this voltage mod, at least compared to Sonic 2 (and Sonic 3, the other game I tried for testing).

Now... I want to point out that in MY case, I have very clearly discovered EXACTLY how MY GP will indicate to me if I'm giving it too MUCH voltage or too LITTLE voltage. Too little voltage... well we should all know what happens when you try to OC with too little... I find that in DrMD, as I up the clock speed one increment at a time and exit out of the menu, when I hit a speed that's too high for the voltage, it usually just goes black screen when I exit the menu, OR, it will play the game for 2-10 seconds and then freeze. At most I may get a few minutes of playtime (used to always get 15mins at 166mhz of GP Engine before it'd freeze).

Now the symptoms I've found for when I get it running too MUCH voltage, is #1 of course you will be able to clock very high :) In my case... if I'm able to stably do more than 188mhz (at some points, I had gotten to where it would run up to 224mhz w/o instantly locking), it is too MUCH voltage for MY GP. This will usually cause the GP to reset after a few minutes of play (which indicates it's only slightly too much) or will cause the game to freeze and the screen to flip out, flickering white bars and crazy stuff that will make you think you just killed your LCD. This is what was happening in Sonic 2 for me.

Thru tweaking and tweaking, and observing these symptoms and taking NOTES this time, being much more methodical than I was the last time (I'm VERY sorry everyone... in my rush and excitement I brought incomplete information to the table to share with you wanting to be helpful... I believe it's not electromigration burning my CPU out slowly, it was me not testing thoroughly enough the first time to see that it was REALLY stable). I found that in my case, my CPU is very sensitive to too much voltage. My target was to be able to sustain 180ish mhz stably... never wanted to go too insane with it. 180mhz has even the roughest games (all but Vectorman) running at 30-40fps in DrMD so no more framerate 'chugging'. So... with that in mind, I tweaked the graphite to get the barest minimum voltage I could get to sustain this speed. The way I have it set now, I can only run up to 184mhz stably... at 188mhz in DrMD, it will usually lock up within a few minutes (freeze, no screen flickering) and at 192mhz, it will freeze instantly when leaving the menu (black screen) or run the game for no more than 10 seconds before freezing. So... not a whole lot of voltage increase over stock *I think* (considering I could do 164mhz stably before and run 166mhz for about 15 mins). Then I loaded up Sonic 2 at 184mhz. This time, it ran well over 45mins with no lockups or resets. But if I up the voltage even a little more, so that I can do 192mhz stably but it locks instantly at 200mhz, and then test Sonic 2 within 10 mins it locks with the flickering screen... too much voltage.

I've said it 10 times already, this mod is VERY sensitive. As others have pointed out, even one stroke of the pencil can make a HUGE difference in what your GP will do. This time around I also followed Jcabrer's tip that he added to his first post well after the thread started, which is, just add tiny amounts to the R52 (one light layer at a time) until it's clocking where you want it to clock, then once your GP shows signs of too much voltage, add even tinier amounts to the R48 (which REDUCES voltage) until it is stable. Trooper seems to be a lucky one that his will take 200mhz apparently indefinately, or you might end up like me, only being able to support a much smaller increase before your CPU cries for mercy. Obviously, Sonic 2 would probably be a great game to test on... at least in my case it is. And I'm betting the symptoms of too much or too little will be the same for everyone or for most of you.

Now... this time I'm bringing much more thorough info to the table, and I hope this helps :) I've been doing a lot of testing over the last 3 days (hence why I haven't posted) to make sure that my 'findings' made sense. NOW my GP will run 184mhz all day... well until the batteries run out :D my record now was just over an hour on Sonic 2 until my batteries quit and almost had me going thinking it was messing up again!!! Thank god I took Troopers great advice this time... if the TV wont work, be sure it's plugged in before trying to fix it :) Put in charged batteries and did another hour of Sonic 2 (to ease my mind) to be sure all was well.

EDIT: thought I should mention, ALL testing has been done using 2300mAh 1.2v NiMh batteries. When I did some testing with 1.5v alkalines, I seemed to get an increase in long term stability, as well as being able to OC higher, w/o changing anything else. Same thing might happen with an AC adapter I bet.... Trooper you cheater! :D :p

and Reesy - I don't do this the 'proper way' becuase #1 I don't have a soldering iron anymore so that would increase cost for me right there and #2 ARE YOU KIDDING ME??? The points you have to solder are SOOOOOO small I would not DARE try to do this myself... I've sodered a few things in the past like mod chipping my Dreacmast and PSX and let me tell you those connections were small and a PAIN in the ass to get right w/o the sodder getting onto other contacts... there's no way I would try doing that 'proper' mod on my GP. Anyways, I'm fairly confident that THIS time I got it right.... I have tested it much more thoroughly... and I feel that since the voltage increase is very likely only a small one to only be able to run 184mhz, I am probably perfectly safe, if Trooper's daredevil marathons are any indication. Yeah this method is still a pain in the ass to get it right (though some have gotten lucky and got it on the first try or so instead of spending several hours like me, though now I feel confident I could do it in less than 1-2 hours) but at least it's much easier to UNDO it if I find I messed up.
 
mine clocks to 204mhz but the vcore is very high , i think im going to revert it back to normal , i mean what games / progs need higher than 166 anyways? i only tryed this mod cos i was bored with my gp but now theres a new sonic doom mod in the works i wanna keep it alive and not fryed for that...



Steve
 
The_Sheik posted on Apr 30 2005 at 01:27 PM said:
just a lil' question, to mesure the voltage core do I need an external alim?

Nope, but its easier with an external alim..

Are the testing points right ? Because I can't believe my core runs at 1.47V and OCs to 220 MHz.. Besides, am I the only one having a wavy effect on the LCD when I put too much graphite on the resitance ? I put it only on R48 by the way
 
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thanks a lot, I wonder how I could put the batteries on if it doesn' t connect on the right side but I will retry! :D
 
The_Sheik posted on Apr 30 2005 at 04:51 PM said:
thanks a lot, I wonder how I could put the batteries on if it doesn' t connect on the right side but I will retry! :D

Do like I did .. tape them with a wire :p
 
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bast525 posted on Apr 29 2005 at 08:52 PM said:
Update time :D

This is gonna be a VERY long one, three days of fiddling and testing and non posting all coming out in one post here :) You have been warned.

Again, I seem to have found some interesting patterns which I think are giving some small bit more info on how this works, how it doesn't work, etc. in the case of my GP at least....

I've found that different programs will run stable at different speeds. Mostly I've tested this with MAME, DrMD, 3DRoter (3d tunnel test), and Atari 800 emulator. I can confirm that Alkalines (Energizer/Duracell) do provide a more stable consistent output, but I prefer to use NiMH for obvious reasons (by the way, I've also been able to recharge spent alkalines on my NiMH charger once or twice).

With MAME, I've also found that certain games run more stably than others, so the main cause of instability seems to be fluctuating voltage (buttons pushed, music played, fast screens, etc...).

Also, with NiMH The ability to clock in the last 5 to 7 minutes of battery life drops rapidly.
 
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jcabrer posted on May 1 2005 at 01:53 AM said:
Also, with NiMH The ability to clock in the last 5 to 7 minutes of battery life drops rapidly

Found that one out the fun way :) in one of my earlier posts on this thread... got me started on the whole chasing my tail thing.

Well Sonic 2 will still run seemingly indefinately at 184mhz w/o locking so I'm assuming my voltage is good, this is after 3 days so... I dunno just saying I got my fingers crossed. I ran a fully charged set of batteries all the way down so well over 2 hours it ran just fine. Makes sense that maybe Sonic 2's voltage requirements are more since it moves so fast and such vs. Castlevania... So far I haven't had any stability issues in Mame either playing a few games here or there for 10-20mins at a time. And I've played a lot of Little John and GP Engine as well with no problems.

And yeah, I hope my GP lasts long enough to enjoy that Sonic Doom mod as well! that thing looks AWESOME!!!
 
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firefly1201 posted on Apr 30 2005 at 06:24 PM said:
Erm.. what's an Alim? Sorry if this is dumb...
The alim is the thing who provides the voltage (electricity) to the GP

Zap posted on May 1 2005 at 02:21 AM said:
Do like I did .. tape them with a wire :p
You' re a genius!! :D
I will try it in a few minutes!
 
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