Returning an overclocked B&W G3 to normal

[Pinstripes]

I've got an overclocked B&W G3 I was given a while back. I use it as a server, but since it's on almost 24/7 my electricity bill has gone up. I'd like to return it to the stock 300Mhz (it's at 400Mhz now.)

There are overclocking instructions here: http://lowendmac.com/macdan/02/0710ek.html how do I reverse this? Do I take jumpers off to bring it back to normal?

Any help appreciated! [] ]'>

 

[Franklinstein]

Two ways to undo an overclock like this: replace the modified jumper block/individual jumpers with a stock jumper block, or configure the modified jumper block/individual jumpers to mirror the setup of your original system.

I'll assume that you're using individual jumpers here. In your case, you'll need to locate pin 1 on the jumper block (SPEED/CTL is printed down the side of the block) - there's usually a little number 1 printed on the upper-left-hand side of the jumper block to identify pin 1. Then, use the instructions on that page to configure the top four sets of jumpers to reflect 300MHz - essentially, this would involve placing jumpers on sets 1, 2, and 3. Leave the others alone, as only the top four sets directly affect the processor frequency and the rest should already be properly configured.

These things take very small jumpers, like the kind used on old SCSI hard drives. I'm afraid I can't remember where to get more other than maybe Radio Shack.

 

[alk]

Dropping down to 300 MHz from 400 MHz isn't going to make much of a dent in your energy bill... It would be better to use Energy Saver to set up a power on/off schedule that matches the times when you could actually be awake and using the network.

Peace,

Drew

 

[Pinstripes]

Thanks for the help

I found a pin setup guide on the internet and got it to 350mhz; I don't have enough jumpers to do 300mhz [xx(] ]'>

If going from 400mhz to whatever doesn't make a difference, I'll fool around with energy saver when I get home tonight.

 

[Byrd]

Since the CPU's voltage has not been increased, there will be no discernable difference in power usage at 400 vs. 300Mhz.

I mean come on - that's really tight, it's not the problem You might as well strip the RAM (less watts used) and video card, OS X doesn't need them either! If it's working fine at that speed, you might as well keep it there. I suggest there is something else in your house that's using up power unnecessarily.

JB

 

[MacJunky]

On the topic of CPU voltage, I don't know if I am the only one but I think it would be great to get my hands on some information pertaining to the voltage settings on the motorola G3 ZIF CPU cards for the Beige G3 and B&W G3.

I know it is available for some upgrades and some IBM made ones but I would like to play with an older motorola ZIF.

 

[tomlee59]

Since the CPU's voltage has not been increased, there will be no discernable difference in power usage at 400 vs. 300Mhz.

Well, the power consumed by digital logic ("CMOS" to be specific) depends linearly on clock frequency, and quadratically on voltage. So, there is most definitely a difference in power consumed by the cpu at those two clock frequencies (which is why cooling the chip is sometimes a limitation in overclocking). But I agree that the difference is inconsequential as far as the overall mac's power consumption is concerned, because there's a lot of other stuff that consumes more.

 

[TylerEss]

I dunno what the specs look like on the B+W PSUs, but it's common for an older PC to waste more electricity in low PSU efficiency than they actually use!

That said, it won't hurt to lower the clock of the CPU... just don't expect it to help overly much.