Welcome to the MacNN Forums.

l008com · Jul 5, 2003, 12:22 AM

I am hereby against overclocking. I've 0 for 2 when it comes to overclocking. Computer on is my server, it PowerTower Pro with a 350 MHz G3 zif in a zif carrier running OS X Server 10.2.something. I overclocked it to 400 MHz and everything ran great. The powertower has excellent cooling, the processor honestly ran cool to the touch. And with server monitor, you could see that on average it only used 5% of the CPU. With such a cool processor running such a light load, you'd think it would OC easily. At first it was great. But then it started crashing once in a while. Sometimes a kernel panic, sometimes a hard freeze. It seemed to focus around heavy use of file sharing to or from the server, so I began to think my ethernet card was bad. It started crashing more and more often until finally it stopped booting all together. I spent a long time trying to coax it back to health and I was just about to replace it when I noticed the clock speed was funny, it was running much faster than it was supposed to in OS 9. So I turned it down to 300 MHz (it is rated at 350) it has been solid as a rock ever since, not one single crash or anything, its been running so long my internet has tweeked a few times and I needed to reset my modem while the computer stayed on chugging. I haven't tried turning it back up to 350 where it belongs, its running so well now I'm kind of afraid to.
Computer number two is a blue and white G3. I bought a 450 MHz G4 for it. I turned it up to 500 MHz and at first things seemed to run fine. But then I noticed it would freeze once in a while. Sometimes I'd go to wake it up and it would be frozen, one time I was watching a movie on it, its purpose for being, and it froze in the middle of it. I then turned it back down to 450 and all is good. The moral of the story is overclocking Motorola processors is bad. My main computer is a Dual 533 G4 and if you were to overclock, the next jump from there is dual 600. And there is NO WAY I'm going to try that. FAR too risky.

Thats my take on Mac overclocking.
My server still runs great, the only thing that takes a while is displaying a days worth of web stats with a 12 MB SQL table.

vmarks · Jul 5, 2003, 07:57 PM

First of all, don't overclock a server.

Servers are supposed to be set up to be reliable, not hacked for greater performance at the risk of reliability.

Second of all, Don't OC 50mhz at a time. Use lesser amounts. Go slowly to see precisely where stability drops off.

Also, use much more agressive cooling when OCing.

There's nothing wrong with overclocking provided you know the risks involved beforehand and either accept them as the worst possibilities or work to mitigate them with better cooling.

l008com · Jul 6, 2003, 01:04 AM

Originally posted by vmarks:
First of all, don't overclock a server.

Servers are supposed to be set up to be reliable, not hacked for greater performance at the risk of reliability.

Second of all, Don't OC 50mhz at a time. Use lesser amounts. Go slowly to see precisely where stability drops off.

Also, use much more agressive cooling when OCing.

There's nothing wrong with overclocking provided you know the risks involved beforehand and either accept them as the worst possibilities or work to mitigate them with better cooling.

50 MHz is the smallest amount you can OverClock by, unless I'm missing something. And as far as cooling, the server was cool to the touch, I've never seen any processor run that cool, it was like the machine was off, i was shocked.

littlegreenspud · Jul 6, 2003, 03:42 PM

I overclocked my B/W G3 350 to 450MHz a year after I bought it and it is still running perfectly over 3 years down the line.

Spart · Jul 6, 2003, 10:39 PM

I'm wondering how far I could push my old 233MHz iMac. The plan is to build a new case and make the processor water-cooled (as compared to its current state, one fan keeping a monitor, 7200RPM drive, 233MHz G3 w/tiny as crap heat sink cool). I could drop in a 333MHz card for cheap off of eBay, and maybe push it up to 433 with the water-cooling.

The machine would simply be a home file server mostly for backups, and on the side play MP3s. It would probably be off at night. 333-433 possible with a massive cooling upgrade?

bowwowman · Jul 16, 2003, 06:56 PM

re: >>>>I overclocked my B/W G3 350 to 450MHz a year after I bought it and it is still running perfectly over 3 years down the line <<<<<<

me 2! It was still running smooth when I got my G4/550 upgrade from OWC....

And I overclocked IT to 650 after 2 weeks

Been running great for over 6 months now........

The only additional cooling I put in was a small, flat fan on top of the heat sink, it runs as cool as a cucumber all day & night !

sniffer · Jul 20, 2003, 10:01 AM

How much a cpu can be overclocked vary from chip to chip. When they make the chip, they all are the same. They runs special tests on each chip to see what clock rate it supports after the chip is made.

x user · Jul 21, 2003, 11:29 AM

You've just had some bad luck, I O/Ced my iBook 500 to 600mhz 100mhz bus. No problems. I'm pretty sure the processor was a 550mhz clocked down to 500 though.

hadocon · Jul 24, 2003, 12:27 PM

Originally posted by Spart:
I'm wondering how far I could push my old 233MHz iMac. The plan is to build a new case and make the processor water-cooled (as compared to its current state, one fan keeping a monitor, 7200RPM drive, 233MHz G3 w/tiny as crap heat sink cool). I could drop in a 333MHz card for cheap off of eBay, and maybe push it up to 433 with the water-cooling.

The machine would simply be a home file server mostly for backups, and on the side play MP3s. It would probably be off at night. 333-433 possible with a massive cooling upgrade?

My question is why? This is a lame project. I am not trying to be mean, but seriously. This would be an expensive and time-consuming. Even if you could clock it up to 433 you would still have a slow computer.

My opinion is that watercooling is retarded. So much time and money spent on a machine that will be obsolete in a few short months regardless of how high you OC it.

If you have money and time to burn try getting some nice software (Pshop, FCP, flash, Programming... etc.) and learn to use it well. These skills wll last a lifetime. It will bring joy, and perhaps you will be able to make some $ using it.

Just my 2 cents...

Anyone disagree and think a project like this is worth the effort?

l008com · Jul 24, 2003, 04:55 PM

Water cooling isn't the best idea, but say maybe putting it in a custom case, like made of wood, and using some big CPU fans to make a wind tunnel out of the box, for some real serious cooling, that would be a fun project, and it couldn't be expensive at all either. Although no matter how cool you make it, it simply might not be able to run much faster than 233. Then again, on second though, and over-clocked 233 imac/water cooling system/fish tank combo device would be wicked cool!!!

sniffer · Jul 26, 2003, 03:48 PM

Cooling isn't everything. There is a limit on how much a setup can be overclocked. It depends a lot on the quality on the components etc. But OTOH it can be very learning experience to push your old hardware for what it's worth. Water cooling is the way to go if you get it right. Good luck.

(Sorry Spart, I don't have a direct answer to your question.)

Dapple · Jul 28, 2003, 01:31 PM

Originally posted by hadocon:

My opinion is that watercooling is retarded. So much time and money spent on a machine that will be obsolete in a few short months regardless of how high you OC it.

The thing is, the watercooling system can be used over and over again, regardless of the processor you're cooling. This is the same principle behind the phase change cases: They're not going to change much, so they'll last for a long time.

zeekyhbomb44875 · Aug 29, 2003, 09:57 AM

not only with bus and cooling uppings, you need to up the V core to the CPU for a better overclock. more voltage DOES mean more overclock. and you said the processor was cool to the touch. you're probably referring to the heatsink. it's likely that he heatsink is much cooler than the actual core of the CPU due to bad heat transfer. you could get better heat transfer from ensuring that both contact surfaces are as smooth as possible (google lapping heat sinks) and use a good thermal interface material, such as arctic silver 3.

itomato · Aug 29, 2003, 02:03 PM

Originally posted by hadocon:
My question is why? This is a lame project. I am not trying to be mean, but seriously. This would be an expensive and time-consuming. Even if you could clock it up to 433 you would still have a slow computer.

My opinion is that watercooling is retarded. So much time and money spent on a machine that will be obsolete in a few short months regardless of how high you OC it.
<snip>
Just my 2 cents...

Anyone disagree and think a project like this is worth the effort?

Uh-huh. Would you like to perfect a water-cooling design on your G5, arguably a machine that could honestly benefit from watercooling/heatpipe tech? I for one, would rather beat up an iMac.

But, that's my $.02.

zeekyhbomb44875 · Aug 31, 2003, 12:42 PM

if you have the resources (CNC mill) to make the water block for a G5, it wouldnt be any truble to make the waterblock for the CPU. then add a pump, some hose, and a rad and a res is optional. hardest part is millin the block for the CPU. i'd love to see a phase changed mac. not just a modified vapo or prometia, a home brewed system :-) too bad im a poor child and cant afford anything that fun, and if i could it would be on an AMD CPU.

Souljah · Sep 3, 2003, 09:23 AM

400 >450 over a year ago with no problems.Next on the list either a Giga1.0 >1.2 or sit on my hands and wait for an official G4 1.6 announcement.

bmmp · Sep 3, 2003, 07:51 PM

hadocon's reply is funny.

true, you could always be spending more time learning programming or flash skills that you could protentially profit from, but it's appearently obvious that Spart enjoys modding his computers, possibly more so that programming or flash (and it'snt being

the point to life?).

You make money modding by doing it yourself instead of paying someone to do it for you, not to mention more fulfilling. Like educated gambling.