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pman68 · Mar 1, 2004, 12:24 PM

Just wondering if anyone has tried this yet? I'm especially interested in the low-end G5, the 1.6GHZ model. Will it go to 1.8? 2.0?

I just checked XLR8 and there's nothing posted yet. Maybe there is an issue with the FSB or something? By now (with other mac products) there are usually Japanese sites with complete pics on how to overclock.

Maflynn · Mar 1, 2004, 01:45 PM

I dunno about you if you have money to burn, but that's taking a giant gamble, plus you will be voiding your warranty.

Mike

The Placid Casual · Mar 1, 2004, 03:12 PM

Originally posted by pman68:
Just wondering if anyone has tried this yet? I'm especially interested in the low-end G5, the 1.6GHZ model. Will it go to 1.8? 2.0?

I just checked XLR8 and there's nothing posted yet. Maybe there is an issue with the FSB or something? By now (with other mac products) there are usually Japanese sites with complete pics on how to overclock.

Well I think there are custom chips running the processor to FSB ratio, cooling fans, and pretty much everything else. If any one of these is messed with, things will not work... and you have an expensive ornament.

G5s are not like x86 where you can add a Swiftec cooler, or peltier cooler, 90mm CPU fan, lap the HS, grab the arctic silver and overclock the FSB in incremants of change the mutlipier... the G5, and Apple stuff in general is a totally different beast.

I suspect that you would be looking at old school jumpers and a soldering iron.... and a lot of failure.

Peace,

Marc

zac4mac · Mar 1, 2004, 03:53 PM

Typically, processors in Macs have much less available headroom than x86 processors. They have been such a small group that they were actually sorted according to their abilities, whereas Pentiums and Athlons were all the same batch and jumpered down to their sale-speeds - eg a friend took a 700MHz Athlon, reconnected a few laser cut jumpers on the chip and had a 1.2 GHz part(that melted 5 months later). I OC'd a G3 in a PM8500 from 400 to 454, and bumped my dual G4-500 to 550. Both have been running 24/7 for over 3 years. Not enough gain to even consider doing it to my new dual 2GHz G5 that cost almost 4 grand. I think the days of overclocking for any appreciable performance gain are past. You'd have to OC the whole system, not just the processor.

Z

pman68 · Mar 1, 2004, 06:25 PM

I Guess that's why it hasn't been done yet. In the previous generation Macs, it wasn't that difficult. Just removing a jumper here or there. But I guess the G5 systems are different.

Thanks for the info anyway....

t_hah · Aug 23, 2004, 01:21 PM

Bump...has anyone seen any info on G5 overclocking yet? I tried to search the web, but no luck yet. There were some japanese people in the past that posted articles on overclocking Macs, have they been able to do this with the G5s yet?

Thanks,

t

Big Mac · May 14, 2005, 07:50 AM

Anything nu on this front or concerning possible processor upgrades? My DP 2.0 is plenty fast, but it's always nice to know one's options for the future, if any exist.

NY152 · May 14, 2005, 08:50 AM

Originally Posted by Big Mac

Anything nu on this front or concerning possible processor upgrades? My DP 2.0 is plenty fast, but it's always nice to know one's options for the future, if any exist.

Looking at the intro video for the upcoming xbox 360 with it's triple PowerPC 3.2 GHz processors makes me realize that Apple has to be on the verge of releasing something over the top. I'm afraid my dual 2.7 is going to feel slow real soon.

Lateralus · May 14, 2005, 02:47 PM

For the millionth time: The Xbox does not use a G5. It's PowerPC is not even in the same realm as the G5. The Xbox is no indication of what we can expect from the G5.

danman · May 14, 2005, 07:14 PM

how do you know? Do you work for MS or IBM?

Lateralus · May 14, 2005, 07:16 PM

I know how to read.

rotuts · May 14, 2005, 07:59 PM

Excellent Lat!

but I saw in one of these forums that a G4 was changed with changing some resistors. does any onw remember that thread? was in in the mini? I couldn't find it by a search or anything here or in mini.

id like to save it

thanks sorry if sl OT.

rotut

danman · May 15, 2005, 03:09 PM

Hmm... then I wonder why MS buys a ton of G5's for development on Xbox 360 games? It's because the G5 is close to the specs for the Xbox 360 procs and dev environemnt.

http://news.com.com/Xbox+360+demos+r...html?tag=st_lh

"We purchased a number of Apple G5's because very specific hardware components of the G5 allow developers to emulate some of the technology behind future Xbox products and services," a Microsoft spokesperson said in a statement. "This is an interim development tool that will be replaced with a more powerful and comprehensive solution later."

Lateralus · May 15, 2005, 04:53 PM

News.com, heh.

Try ArsTechnica.

Microsoft bought the G5s as a hardware reference platform for development. PowerPC code is PowerPC code.

cgc · May 15, 2005, 05:15 PM

Originally Posted by rotuts

Excellent Lat!

but I saw in one of these forums that a G4 was changed with changing some resistors. does any onw remember that thread? was in in the mini? I couldn't find it by a search or anything here or in mini.

How was it changed? A couple of resistors would do nothing to the speed of the chip.

Lateralus · May 15, 2005, 06:02 PM

Originally Posted by cgc

How was it changed? A couple of resistors would do nothing to the speed of the chip.

How do you think the processor speed is set? It is controlled by resistor configuration on either the motherboard or the processor daughterboard.

Cadaver · May 17, 2005, 08:16 AM

Genehack · May 19, 2005, 06:10 AM

Actually,it IS possible.
Here You go:

http://24.13.234.151/overclock/g5.html

qnxde · May 19, 2005, 06:41 AM

Originally Posted by danman

Hmm... then I wonder why MS buys a ton of G5's for development on Xbox 360 games? It's because the G5 is close to the specs for the Xbox 360 procs and dev environemnt.

Do you even know how much 3x3.2ghz G5's would cost? *recalls apple spare parts list for G5 CPU prices* Even MS couldn't get the price down enough to make putting 3 of them in a consumer console still financially profitable. The console itself would cost $1500-$2000!

lothar56 · May 19, 2005, 11:56 PM

MacAddict overclocked a Mini by soldering some resistors. Apparently it's possible to take it up to 1.55 GHz or something like that.

rotuts · May 20, 2005, 11:57 AM

I justs found the ref to the mni with pics:

http://www.lbodnar.dsl.pipex.com/macmini/

rotuts

cgc · May 21, 2005, 10:23 AM

Originally Posted by Lateralus

How do you think the processor speed is set? It is controlled by resistor configuration on either the motherboard or the processor daughterboard.

Roger. For some reason I was thinking along a different line (we modded our Amigas by swapping crystals...)

P · May 29, 2005, 10:25 AM

You can overclock in different ways. The crystal trick you used on the Amigas (and that did work on Macs back in the Nubus days, I know you could do it on 6100-8100s) meant changing the actual bus speed. When you fiddle with resistors, you try to get a different multiplier compared to some known clock - usually the PCI clock, which 33.3333 MHz. You can overclock the PCI bus, but some things require it to have the specified clockspeed and won't work. Also, you overclock a lot of things by doing that, because the PCI clock is used a reference by other standards (like AGP).

yikes600 · Jun 3, 2005, 10:09 PM

Even if you were to change the resistors on a G5 daughtercard to overclock it, OS X would reject the higher speed and underclock the machine instead. OS X does a check to see if the card is set at the same MHz as what the motherboard originally came with. If it doesn't match, the machine goes into a safe-mode, underclocking the machine and keeping fans at full blast.
I posted more about it here:
http://www.macworld.com/forums/ubbth...72&Search=true
I'm the second poster (Yikes 650).