overclock a purple imac g3

Can't be done

Nope - no 'software' over clocks are available, and I doubt 50MHz would be that noticable. You could try upgrading the OS to Tiger (10.4.11) but don't forget its a slow CPU and would be slow. Tigers requirements are a 333MHz G3 or higher with 256MB RAM recommended. This Mac supports up to 512MB of RAM using. Also a quick note, there are no 'ram modules' on the CPU. You'll find that this is actually backside cache for the processor.

See the attached image for a quick diagram of the parts:

pac

To overclock a tray loading iMac you have to solder resistors on the processor card. I'm attaching a couple of pics showing where the relevant resistors are and the configurations for various speeds.

Wayne

50mhz will be noticeable at such a low starting speed. Clocking my 400mhz PowerMac G4 to 450MHz made a good difference in performance.

Don't know. I have a few spare boards to cannibalize. In any case just moving the existing ones to the new position would do.
For removing resistors you really need two soldering irons or you can easily damage the processor card. Those traces are really delicate.

Wayne

This sounds difficult and dangerous.

If getting components is an issue DON'T try to overclock !

With one soldering iron it's difficult and dangerous, with two it's very easy.

Wayne

I did this before to an eMac.. It worked, but I don't think I would bother again. It was very tedious, and there's a real risk of fudging up the Mac.
However, the chances are that if it doesn't work properly first time, then you try again at a lower speed until it does work.

You absolutely NEED good soldering skills. And preferably at least a little experience with surface mount technology also. Oh, and you need a good eye too. Those soldered jumpers/resistors are very very small.
For the work involved, I don't think you'll get great gains out of one of these Macs. And as I said, if you have not got any soldering experience, then forget it.

It may not be that worth it, and there are not many upgraded iMacs like that. The most easily overclockable Mac was probably the Blue and White G3, which was done by a set of jumpers on it.

Dude I am the one that gave you that computer so your guess is as good as mine

There's not many processors that fit. The PowerBook WallStreet's processor board fits, but isn't apparently cooperative. There was a upgrade, the Sonnet Harmoni G3. It's around 500MHz, and includes FireWire for most of the series.

The last Sonnet Harmoni G3 upgrades were 600mhz but they're out of production because not many people with tray loading iMacs were willing to spend over $350 for the upgrade. Though if you can find someone with some old stock wanting to clear it out you might be able to pick one up at a fraction of that price.
A better choice if you have to have a crt iMac is one of the slot loading iMacs, they were available in speeds of up to 700mhz.