[Spart]

I've been considering this for a while. I have an old iMac 233, one with minor analog board problems (commonly referred to as GLOD, which stands for Green Light Of Death) but otherwise runs fine. It's one hell of a hot case, one fan keeps a 7200 RPM drive, CD-ROM, 233MHz G3, PSU and CRT cool. Just by feeling the top of the machine after it's been on for a while on a hot day, you can get an idea of how insanely hot it runs with a mostly stock configuration.

The plan is to gut the machine, and put the necessary components into a new hand built acrylic case, roughly 2'x2'x5". Separate it into three partitions, one with two drive bays, one with the motherboard and power filter which would be in the center as much as possible (port access would be recessed into the case) and one compartment for the PSU and perhaps a water-cooling unit.

The question is, could I buy a 333MHz daughter-card off of eBay for cheap, and OC it up to 433MHz if I lower the cache speed? This would be with some wicked cooling...I hear that the 333MHz G3's that made it into the iMacs were copper based, as opposed to the aluminum based 233MHz chips, although I'm not sure of this.

It's an interesting proposition, a 30% overclock is quite a bit. Reading reports on XLR8YourMac.com, however, it seems that people have been successful in taking the 333MHz chip to 400MHz in the original case. Most of them had to install a second fan above the CRT to improve airflow, however. So it makes me wonder: is the limiting factor the chip itself, or the heat it (and the case) produces? With my case, one very powerful fan with a bigger heat sink or a water cooling system will keep the CPU cool, everything else has different cooling.

333MHz to 433MHz - Impossible?

[CIA]

Why not just stick the whole iMac in a mini-fridge? Just run a moniter cable and USB through a hole in the door.

[Spart]

I actually have one to do it with, but I think that it would be a bad idea. Condensation + high voltage electronics = bad mojo.

I know that I can do 400 with the 333 chip and added cooling. It just tickles my mind about the extra 33MHz...

If I use a water cooling system, it will be good enough to cool a P4 @ 3.0GHz (when the fan on the radiator is running at full power, I'll probably turn it down to half.)

[Saetre]

I had no problem at all getting my G3-300 tower up to 475.

[permanent68]

I have the fastest 1st gen iMac in the world, and have a bit of knowledge about this topic.

Alright, the 333mhz, that's what my computer ORIGINALLY was. You can have one of two kinds of chips, the ALUMINUM chip, or the copper chip. www.xlr8yourmac.com provides a piece of software called a "G3 Checker" and it would tell you what rev G3 you have, and if it was copper or aluminum. I originally had aluminum, and sure enough, it ran hot. My mom works as an elementary school teacher, and she brought home her 333 iMac for the summer. So I loaded G3 checker onto it, sure enough, it had a copper chip. So I swapped daughtercards, and the original plan was to attempt to overclock it.

But here's a better idea. REMOVE ALL THE RESISTORS. They're extremely tiny, and I wasn't able to do it in my dorm room, but then put a wire on each of the pads. Then just get a 'dip switch' that has some 'on off' positions, and wire it up. The resistors are not there to provide resistence, but merely to provide an 'on'. So once you have it all together, you should be able to just 'click' the dipswitch to the desired 'combination' of on-offs to get whatever speed you'd like. Try it stock. Then bump it up 33mhz. Then 66. Go until it becomes unstable, but BE SURE TO FIND A COPPER CHIP FIRST! Aluminum cored ones will not overclock very well at all.

Anyway, I was going to do all that, but then Sonnet came out with the 600mhz Harmoni G3 with the firewire input, so I sprung for that, since I really really really wanted to do DV editing. I'd like to overclock the Harmoni but unfortunatly its a completely different card and I have no idea where those 'resistors' are.

- Ca$h

- Ca$h