Who has OCed an iMac G3?

[sp00nix]

I have an old iMac G3 400 with 384mb ram. Im looking to up the speed a bit. The problem is i can only find multiplier mods, no FSB mods. Anyone have any ideas?

[JamesXP]

Do a multiplier mod? I wouldn't recommend FSB mods, no PCI Locks.

400MHz is fine for G3.

[sp00nix]

Do a multiplier mod? I wouldn't recommend FSB mods, no PCI Locks.

400MHz is fine for G3.

As i was standing in the cooling section of micro center, my girlfriend asked me why is it that i can't leave things alone, my desktop is OCed as well as my laptop and its video card, my phone, and even the ECU in my car i have tinkered with. Then this little G3 came around and i had to see how far i can push it. 400mhz may be fine for that G3, but i have an addiction lol.

BTW that iMac has been under my knife before. When it was my buddies it put some high intensity green CCFLs in there and BOY DID IT SHINE! Just last night i thought those things ran too hot for my liking and added a 92MM fan in the hole where you access the wifi card

[splat]

they might have info here: http://www.macxtrem.com/articles.php

[Old Thrashbarg]

no PCI Locks

Actually, there is a 1/4 PCI divider on the B&W G3 towers, so there might be one on the iMac as well. However, the G3 towers also had jumpers to set the FSB... I doubt your iMac has those, so it'd prolly be a bit of trouble trying to change it. (Also, I think 120mhz was the limit anyway... the memory controller couldn't really handle more than that, IIRC.)

Thing is, though, that the G3s didn't really seem to benefit much from higher bus speeds. 100mhz was enough... it wasn't until you got into the higher speed G4s that you really needed more than that. So just changing the multipler should be fine.

Also... don't expect to get more than 450mhz out of that thing. Maybe 500mhz if you find a way to volt-mod it, but don't count on it.

they might have info here:

Looks like they have some info for the first-gen iMacs, but not the later 100mhz bus ones like the OP has.

[splat]

did you look at the OC table too? http://www.macxtrem.com/overclock.php?sort=proc&dir=

[sp00nix]

I guess ill stick with a multiplier mod. Its a pain in the ass. There are a set of resisters to move around instead of jumpers >_<. Maybe i can rig a more real time solution.

[benbaked]

Please post up some pics of your modded iMac. I've never seen one and, well, I'd like to see one. :) Particularly I'd like to see how you fitted the cooling fan.

[sp00nix]

Please post up some pics of your modded iMac. I've never seen one and, well, I'd like to see one. :) Particularly I'd like to see how you fitted the cooling fan.


Will do tonight! The cool CFFL mod isnt in there anymore, but im sure if i get my hands on another set ill toss them in.

[splat]

I guess ill stick with a multiplier mod. Its a pain in the ass. There are a set of resisters to move around instead of jumpers >_<. Maybe i can rig a more real time solution.

that's how all mac oc's are done (at least from what i've seen on that macxtrem.com site.) I was going to oc my 12" powerbook, but Gamoul said the 867mhz proc couldn't be done.

[sp00nix]

I found these from when i did the CCFLs. I told you it shined!:)


http://picasaweb.google.com/elitespoon/Tech


Ill post more of the fan mod, but that not as pretty

[benbaked]

Nice! :thup:

I thought at first you left it finished with the top rear housing removed and I was thinking :eek:

but then I noticed the final pictures with everything together, that looks very nice. Does it interfere with the colors or geometry of the screen in any way while you're using it?

[splat]

that's pretty slick, especially the Ubuntu part :)

[sp00nix]

It did mess up the image at first. The AC from the HV lines caused some hum bars and gauze. I repositioned them until it worked out.

[esveezy]

Maybe software overclocking is possible *ducks*...

When I had my 600 G3 iMac apart, I took a look at the little resistors that determine the multiplier - they may as well be microscopic, since I wouldn't stand a chance soldering them. Of course, you may be able to get away without using resistors, and just use a blob of solder or conductive ink.

Good luck. And if you want to pick up a 600 iMac with a fried ethernet (working wireless), it is here in Tallahassee - Free to a good home.

[sp00nix]

Thats a bit of a hike for me lol. Would you want to part out the wifi?

[esveezy]

I have several Atheros wi-fi cards that will work just like a proper Airport, and maybe even a spare G3 iMac wi-fi adapter, and possibly a proper Airport card somewhere buried. I'll look around, but if I pulled the wifi out of that iMac, it would be limited to FireWire or USB networking only.

I'll PM you if I come up with anything, but I truly dread digging through my pile of parts.

BTW, I tried everything I could think of to get 802.11g working on that iMac (special drivers, a couple of PCMCIA cards allegedly with the same chipset as the Airport Extreme) and nothing even kinda worked. So don't get your hopes up about wireless speed. Best bet (for speed, not looks) there is an 802.11g USB dongle, which will be faster than 802.11b, but limited by USB 1.1.

[sp00nix]

Don't go making a big hassle looking for parts on my behalf. It is running 10.4.x, im not sure what hardware is supported. what i wanted to do was put a USB hub internally for such causes, i have a USB receiver for a mouse and KB that i have on it now that i wanted to integrate.

[sp00nix]

Almost had a scare with this today. My GF sent me a text, when she went to wake it up the screen flashed red and shut off. when i got home it wouldn't boot, it made the power on sound but no monitor or HDD activity. i plugged in an external monitor with no luck. then i unplugged the power and powered on and pull the power a few times. then it only played half of the power on sound. then one more try it made a sicking screech and click, then it booted. Im on it now and i have not shut it off yet.

[sp00nix]

Found the issue, Bad RAM. Now im down to 128 >_<. The colorful little pinwheel is now my best friend! Back to the PC for now.