Mac Mini Overclocking FAQ

I seem to be coming across more and more posts from users asking about or mentioning Overclocking a Mac Mini.

Is it hard? No.

Is it worth it? Yes, definitely.

I'm posting this thread to find out how many people would be interested in me generating a How-to FAQ.

I myself, have successfully overclocked 7, and lost none. A team of us have overclocked 11, and one idiot broke one (but that's another story). I've also been overclocking the 7445 eMacs for awhile now (very similar to the OC'ing the Mac Mini) so I'm very experienced.

If I get enough requests, I'll go ahead and make a FAQ.

On the same level, Does anyone happen to know how to overclock the iBook G4? There was a program for the G3, but not G4. I've got the 1.33 GHz model. I've heard this isn't all that hard, but I have NO idea how to do it as I've only tried overclocking with PCs in the past.

go on mate stick it up it might save millions of new threads asking for it

I say make one! That way when we nail down the FAQ formatting for the official FAQ forum, it should be easy to adapt it

For God's sake, man! POST IT!

I've read a few of your posts and I do believe you know your stuff. So, I trust your results would be typical for anyone with a decent amount of experience tweaking their PC.

I am typing this from my OC'd Athlon T-bird which is getting replaced by a Mini on my birthday (March 14th, woot!). And I've been building PC's for over 10 years. I'm sick of this cheap PC hardware and the annoying OS. I've used Linux since 1999 but it just doesn't have the polish and great proprietary apps that the Mac has.

I have seen another thread in the switcher area that you posted on. The guy says he's going to use "hot tweezers" to pull the "jumpers" off the mobo. Does that work? I don't own a soldering iron, but my wife sure does have some tweezers in her scary bag o' cosmetics. I'm sure I could snatch them while she's not looking and kick the mini up to a respectable 1.58!

This is exciting too, because I was going to buy a stock 1.42 and now maybe I'll go for the 1.25 and get a 60gig 7200rpm drive and some RAM.

Also, it would be extra keen if you could take some photos and show which ones to pull off if you want which speed choices.

repeater75 said:

For God's sake, man! POST IT!

I've read a few of your posts and I do believe you know your stuff. So, I trust your results would be typical for anyone with a decent amount of experience tweaking their PC.

I am typing this from my OC'd Athlon T-bird which is getting replaced by a Mini on my birthday (March 14th, woot!). And I've been building PC's for over 10 years. I'm sick of this cheap PC hardware and the annoying OS. I've used Linux since 1999 but it just doesn't have the polish and great proprietary apps that the Mac has.

I have seen another thread in the switcher area that you posted on. The guy says he's going to use "hot tweezers" to pull the "jumpers" off the mobo. Does that work? I don't own a soldering iron, but my wife sure does have some tweezers in her scary bag o' cosmetics. I'm sure I could snatch them while she's not looking and kick the mini up to a respectable 1.58!

This is exciting too, because I was going to buy a stock 1.42 and now maybe I'll go for the 1.25 and get a 60gig 7200rpm drive and some RAM.

Also, it would be extra keen if you could take some photos and show which ones to pull off if you want which speed choices.

Click to expand...

Well then it looks like I'll be posting a FAQ within the next couple days.

...As far as using hot tweezers to remove the resistors, I guess it’s worth a try, but they would have to be pretty thin tweezers - the resistors are literally no bigger than the tip of a small sewing needle. And I'm not entirely sure how advantageous heating up the tweezers would be in effectively removing the resistors since most standard soldering irons operate at around 800 degrees - so I can't imagine there would be any obvious difference in using hot tweezers or tweezers at room temp... All in all, you are just trying to rip off the resistors anyways.

Also, to bring your Mini to 1.42GHz, a soldering iron is required since the resistor configuration for that particular speed requires that you close an additional circuit (meaning you would have to solder a bridge between 2 of the pins). The configuration for 1.50GHz and 1.58GHz does not require that you close the additional circuit - all you need to do is remove the resistors. So, ironically, it is actually easier to reach 1.50GHz/1.58GHz than it is to reach 1.42GHz, especially if you are an inexperienced solderer.

I do recommend the Cold Heat Soldering Iron (www.coldheat.com) if you are interested in soldering or learning how to solder - you can pick one up at your local radio shack for $20. It is a great tool, especially for beginners.

Meyvn said:

On the same level, Does anyone happen to know how to overclock the iBook G4? There was a program for the G3, but not G4. I've got the 1.33 GHz model. I've heard this isn't all that hard, but I have NO idea how to do it as I've only tried overclocking with PCs in the past.

Click to expand...

Well, its not hard, but its not done with software.

It's very similar to overclocking a Mac Mini - you need to open up your book and remove some 0 Ohm resistors AKA Jumpers to effectively increase the CPU multiplier. I've heard the G4's in the ibooks don't OC as well as the Mac Mini low-power variants.... So in all honesty, I'd say just stick with what you have.

Yes, please definitely post it!

I've got a quick question, which can be included in your FAQ. I currently own the 1.42 mac mini. If I overclocked the system to 1.5-1.52, is there a noticeable increase in the performance? If so, is the difference significant? Which programs would tend to benefit from this?

Regards,

VakeJ

Oh, yes and another cool thing would be if you could include something about how to make the "about this mac" or whatever system properties screens report the correct clock speed for the OC'd processor. You indicated in another post that it will default to saying "750 Mhz" because of the non-standard speeds in whatever reference table the OS uses to report clock speed of the processor.

I just looked at those resistors on my mac mini, they are so small, my soldering iron just seems to bulky for something of that precision, I might have to go get a new one.

falltime said:

...As far as using hot tweezers to remove the resistors, I guess it’s worth a try, but they would have to be pretty thin tweezers - the resistors are literally no bigger than the tip of a small sewing needle. And I'm not entirely sure how advantageous heating up the tweezers would be in effectively removing the resistors since most standard soldering irons operate at around 800 degrees - so I can't image there would be any obvious difference in using hot tweezers or tweezers at room temp... All in all, you are just trying to rip off the resistors anyways.

Click to expand...

For what it's worth...when I mention hot tweezers...I'm not talking about the pair your wife or GF plucks her eyebrows with...I'm talking about something similar to THESE. A friend of mine has a pair...not this exact model...but a similar tool. We've used it before to remove components from PCBs in 900Mhz radios...and I'd imagine it do quite well to remove these resistors here as well. But certainly...a steady hand, good lighting, a nice magnifying lens, etc...all make the job much easier.

mcsenerd said:

For what it's worth...when I mention hot tweezers...I'm not talking about the pair your wife or GF plucks her eyebrows with...I'm talking about something similar to THESE. A friend of mine has a pair...not this exact model...but a similar tool. We've used it before to remove components from PCBs in 900Mhz radios...and I'd imagine it do quite well to remove these resistors here as well. But certainly...a steady hand, good lighting, a nice magnifying lens, etc...all make the job much easier.

Click to expand...

Yeah in your other post, I figured that's what you meant... I was mainly referring to Repeaters remark on using his wife's tweezers - while I'm not sure how practical it is, I suppose its worth a try for anyone with limited SMD and soldering experience.

Well...I was just trying to clear up any confusion. I'd hate to see someone burn their hand or their PCB using some kinda drug store tweezers heated up by their favorite bic lighter!

VakeJ said:

Yes, please definitely post it!

I've got a quick question, which can be included in your FAQ. I currently own the 1.42 mac mini. If I overclocked the system to 1.5-1.52, is there a noticeable increase in the performance? If so, is the difference significant? Which programs would tend to benefit from this?

Regards,

VakeJ

Click to expand...

Well you can only overclock the Mac Mini to specific speeds: 1.42, 1.50, and 1.58. There is no flexibility; you cannot pick a speed in between the defined speeds - the CPU clock multiplies off the unalterable system bus which is why there are significant gaps in the clock speed steps.

I'd say going from 1.42 to 1.58 would bring about a decently noticeable performance increase. You probably wouldn’t observe the increase as much using Office apps, or in just general OS GUI response, but you'd definitely notice the increase in video editing and graphic design apps. I would imagine you would receive a decent FPS gain in games as well.

mcsenerd said:

Well...I was just trying to clear up any confusion. I'd hate to see someone burn their hand or their PCB using some kinda drug store tweezers heated up by their favorite bic lighter!

Click to expand...

Holy crap, I feel dumb!
This is totally embarassing, but that is pretty much EXACTLY what I envisioned when I read your original post about using "hot tweezers"!!

I am truly laughing at this one. Now I have to show my wife this so she can giggle her little butt off too. I don't know why I'm such a glutton for punishment!

At any rate, I never did a lot of soldering but its never too late to learn! I imagine I'll go for the $20 job that was mentioned from Radio Shack.

I can't wait for the guide!

Well...I tried 1.58 tonight...but it's not looking good. I don't know if it's cooling related or not...but 1.58 is freezing Xbench at the Altivec tests just like I've seen other people reporting. I'm going to remove the other resistor later and give 1.5 a try...hopefully that'll be more stable. For what it's worth...everything else seems to be running fine.

mcsenerd said:

Well...I tried 1.58 tonight...but it's not looking good. I don't know if it's cooling related or not...but 1.58 is freezing Xbench at the Altivec tests just like I've seen other people reporting. I'm going to remove the other resistor later and give 1.5 a try...hopefully that'll be more stable. For what it's worth...everything else seems to be running fine.

Click to expand...

Yeah, it may be a cooling issue. I have yet to run into any problems with my 1.58 Minis, but as well all know, all processors are different. You may want to try removing that atrocious thermal pad and throwing some AS5 on the processor instead - you'd definitely bring the temps down.

Well...for what it's worth...Like I said only Xbench is locking up on the Altivec tests. I can run the Altivec Fractal Carbon tests all day long and they run just fine. I just can't help but wonder if this is a true issue with Xbench and not an honest issue with the processor. Who knows...I'll slap some Artic Silver on it later and see if it helps any...maybe I'll even break out the temp probe if I get enough motivation to do it

For Falltime:
On your mini OC's, were these all the same original clock speed, or a mixture? (i.e. stock 1.25's to 1.58 or stock 1.42's to 1.58?) Also, on how many that you have overclocked did you replace the thermal pad with Artic Silver paste? (I assume that's what you're referring to). On those that you didn't (if there were any) - have you seen any stability issues? In replacing the thermal pad, how is the heatsink removed from the processor? Are there any tricks to it so that you don't crack the cpu core or is that just not a concern with G4's? My Athlon has been running OC'd for over 3 years very reliably - albeit very noisily with the huge fan on that baby. I need a mini just to keep from getting a divorce! Wifey hates that my comp sounds like an aircraft carrier!

Again, thanks for sharing the knowledge. It is greatly appreciated. If I can save $100 on the system by getting a 1.25 and at least getting 1.5 out of it, I can spring for a 7200 RPM 60gb Hitachi drive and my speed concerns are gone gone gone.

Well...this is of course only my experience over the last few days...but I've been running my orginally 1.25 at 1.58 for a few days now. I've mastered and burned DVD's, played many tunes, surfed many a website, played around with the Altivec Fractals Carbon tests, and more...and often at the same time. I've never experienced any abnormalities with the exception of Xbench locking up at the Altivec portion of the CPU test. Beats me...but seems pretty **** stable with the exception of the bench program. I don't know about everyone else...but for me that leads me to believe that either Xbench has some sort of compatibility issue or...I'm just unable to replicate the exact process that it is using during testing in day to day operations. Either way...the computer is snappy and responsive and has failed to have any issues with day to day usage so I plan to stay at 1.58 for what it is worth.