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Overclocking a 1.5GHz powerbook...
- Thread starter invaLPsion
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blue&whiteman said:
Gee, I didn't think I was too stupid in overclocking my old celeron 300A to 450Mhz a few years ago. The celeron chip cost $200CAN and at 450Mhz, ran slightly faster the $1100CAN P2 450Mhz chip at the time. That computer lasted me 3 years--until my next upgrade.
Of course, you could call me stupid for buying a pc, but that's a different matter.
topicolo said:
I have heard that the celeron can be overclocked like crazy. glad you got so much use out of it and saved all that money. I meant idiot in a only harming yourself way.
saabmp3 said:
i wouldn't be so hasty. there is a possible firmware hack out there yet to be developed.
most likely it would require a change in jumpers, but it could be accomplished with a firmware modification.
I still don't understand the reasons, but in my research I found there are those out there doing quite well.
http://forums.macnn.com/showthread.php?threadid=188573
http://homepage.mac.com/giantmike/tests/overclocking.html
http://www.spymac.com/forums/showthread.php?threadid=74331&goto=lastpost
even G3s
http://www.lowendmac.com/macdan/02/0710ek.html
I just wish someone would take the time to explain what overclocking is and what benefits if any are achieved.
http://forums.macnn.com/showthread.php?threadid=188573
http://homepage.mac.com/giantmike/tests/overclocking.html
http://www.spymac.com/forums/showthread.php?threadid=74331&goto=lastpost
even G3s
http://www.lowendmac.com/macdan/02/0710ek.html
I just wish someone would take the time to explain what overclocking is and what benefits if any are achieved.
The G4s the Powerbooks use are the PPC 7447 which is different from the 7457, which is the desktop counterpart, because of the lack of L3 Cache Circuitry. Because of this the 7447 can't use an L3 Cache but uses less power & creates less heat. Past powerbooks that have had an L3 Cache used the PPC 7455 which was the G4 used in the last Power Mac G4s. The iBook G4 800, 933, & 1GHz (14") used the PPC 7445 which is just like the 7447 in the way that it is missing its L3 cache circuitry. Heres how you find what CPU you have.
Cut & Paste this into the terminal:
ioreg -l | grep cpu-version
Then check the values against this chart I've made for the PPC750 & PPC 74xx CPUs that came after the 7410:
PPC 750 G3 8x Multiplier = "cpu-version" = <00088201>
PPC 750L G3 10x Multiplier = "cpu-version" = <00088300>
PPC 7440/7441/7450/7451 = "cpu-version" = <80000201>
PPC 7445/7455 = "cpu-version" = <80010303>
PPC 7447/7447A/7457 = "cpu-version" = <80020101>
If you run that command on a Mac with an original G4 (7400 or 7410; i.e. the PB G4 15" 500MHz or the Sawtooth/DA 500/533MHz G4) or a 750CX-FX (i.e. any iBook over 400MHz & any iMac G3 over 500MHz) please post your value & Mac. That would help me to complete the table ;-).
Also you could overclock some Macs using software. For a while you could overclock PPC 750FX based iBooks (any White iBook with a G3 CPU & 512KB Cache) using Apple's CHUID Tools but Apple removed that ability after it was being used for overclocking. Powerlogix's CPU director may also work on those models. It works on PPC 750FX models because they support setting the clock speed on the fly. The 7447 & 7457 series support this I believe but I don't think it has been implemented in software by Powerlogix yet & Apple may have disabled that feature on the PB G4.
If you really want to overclock it go to Motorola's Web Site & download the white paper on the 7447 & see how you configure the Bus Speed Multiplier PLL pins. Then crack open the PB & change the pins. If you screw up then you're going to have a 2K paperweight. Enjoy.
Sparky's said:
overclocking is just as it sounds. you are raising the CLOCK speed of your cpu to OVER the original spec. some chips/systems can be overclocked and never have a problem, other times it will reduce the life of the chip, and still other times you may fry your chip.
when you overclock, since you are raising the frequency (speed) of your chip, you will (basically) have a faster system. it also sometimes changes the frequency of your system bus. this is not always 100% the case, but why would you overclock your chip, only to lower your bus speed... and have a slower machine?
since an overclocked system will run hotter, most people who do this as a permanent change, will add more cooling for the chip. in a laptop this is not possible inside the case usually, and you run a greater risk of system failure.
some chips can be overclocked by changing the firmware of the machine, other by changing some user moveable jumpers, and still others by changing soldered jumpers. these jumpers control the multipliers used by the system to determine the frequency of the cpu and system bus.
i overclocked my b&w g3/450 to 550+? (not sure) by moving a jumper. i added a fan on top the heat sync, (to be safe) and it worked fine.
Typical of Mac users...
Ya know,
I'm a mac user for sure. 100% converted. That being said, I came from the PC enthusiast side of things. I have watercooled computers to overclock them as fast as possible. I have implemented peltier devices to achieve sub zero temperatures. Whenever I had questions about how to squeeze the most performance out of my PC, people would help me out.
On a mac forum, people criticize the man for even attempting to be completely innovative, for trying to make his brand new, fast PB even faster! I don't get it.
-Kevin
Ya know,
I'm a mac user for sure. 100% converted. That being said, I came from the PC enthusiast side of things. I have watercooled computers to overclock them as fast as possible. I have implemented peltier devices to achieve sub zero temperatures. Whenever I had questions about how to squeeze the most performance out of my PC, people would help me out.
On a mac forum, people criticize the man for even attempting to be completely innovative, for trying to make his brand new, fast PB even faster! I don't get it.
-Kevin
No, don't overclock your macs, you'll be giving into the MHz myth... that more MHz is a faster computer
There have been several PPC chips used in the past couple of years. So depending on which two you are comparing, they may or may not be the same chop, even at the same processor speed.Mav451 said:
Also, the current iBooks and Powerbooks both use (probably) 7447A chips. Alhough, they are probably 2 or 3 different versions of the 7447A.
The emAc that was announce coukd be either a 7447 or 7447A. The current generation of Motorola PPC chips deisgned for Laptop use are also reasonable to use in a desktop system.
The iMac and the eMac are also probably using 7447 variants since they do not have L3 cache either.Mac_Max said:
G4 systems without L3 cache and only 256MB of L2 cache were probably 7445 chips. The 7447 (and 7447A) have 512MB of L2 cache.
When you overclock, the mhz myth isn't a myth. The processor stays constant. It's running it at its stock clockspeed or a clockspeed higher than that which it is spec'd for. The overclocked one will always be faster (unless you have to decrease speeds of other components in exchange for a faster CPU speed)ZildjianKX said:No, don't overclock your macs, you'll be giving into the MHz myth... that more MHz is a faster computer
Bhennies said:I'm pretty sure they set it up properly on barefeats. I would hope?
Who knows. They still haven't tested a 128 VRAM 9700 only a 64...
Some things to consider
If you intend to notch up the frequency on a laptop improving cooling can be tricky. I suggest looking into improving the performance of fans or blowers and sacrificing noise and battery life. One or more powerful blowers could do the trick if you can find the space to mount them and the proper voltage to power them.
Some hacks are possible just with software and firmware modifications. Start by disabling all power saving features that affect the cpu. See if you can disable the automatic clock speed reduction feature that is part of the 7447A in the new Powerbooks. You could also look into ways of running the fan or blower at 100% all the time rather than at a variable speed.
If would be a nod to Apple if you would modify your external appearance in some way to indicate that your Powerbook has been modified so those who see it will know that the extra noise isn't normal. Most people would rather preserve their warranty and the reliablity of their system rather than make such risky tradeoffs. However I applaud those who have the guts to try to squeeze a bit of extra power out of their computer as long as they are willing to accept both the positive and negative consequences of their actions.
Also note that maxing out the ram is a simple and effective way to improve overall system perfomance.
If you intend to notch up the frequency on a laptop improving cooling can be tricky. I suggest looking into improving the performance of fans or blowers and sacrificing noise and battery life. One or more powerful blowers could do the trick if you can find the space to mount them and the proper voltage to power them.
Some hacks are possible just with software and firmware modifications. Start by disabling all power saving features that affect the cpu. See if you can disable the automatic clock speed reduction feature that is part of the 7447A in the new Powerbooks. You could also look into ways of running the fan or blower at 100% all the time rather than at a variable speed.
If would be a nod to Apple if you would modify your external appearance in some way to indicate that your Powerbook has been modified so those who see it will know that the extra noise isn't normal. Most people would rather preserve their warranty and the reliablity of their system rather than make such risky tradeoffs. However I applaud those who have the guts to try to squeeze a bit of extra power out of their computer as long as they are willing to accept both the positive and negative consequences of their actions.
Also note that maxing out the ram is a simple and effective way to improve overall system perfomance.
Sparky's said:
Each user has a different set of needs and wants. For example some people don't mind extra heat and noise in order to get a bit of extra performance while others might just desire maximum battery life. While most of us are happy with the more balanced approach provided in the stock configuration this is not true of everyone. Modifications and the tradeoffs they entail are therefore reasonable in my opinion.
Mac_Max said:
Hrm. Mine is 80030101. It's the new 1.33 12" powerbook.
re: overclocking, my 500 MHz iBook ran continuously, 24 hours a day, at 600 Mhz since the month I bought it over three years ago until I purchased the new powerbook a few days ago. Overclocking the ibook required great care and surface level soldering using the method publicized at the time on xlr8yourmac, and I made some cooling modifications with copper sheetmetal while I was in there - it ran much cooler afterward than it did out of the box.
Since it was a bus overclock, more than just CPU speed was afected. For example, gaming performance (tested with Qake3Arena and Alice) on that machine was far better, although I did also have to improve the cooling on the old ATI chip before it was happy being pushed that hard. For all appearances, the machine is a 600MHz machine - it operates that flawlessly. Battery life was improved (when I changed the bus speed, I chose a wider gap between high and low speed operation -- it has both a higher top speed and lower bottom speed than stock).
In my case it resulted in a more usable laptop, and since I used it daily, it probably extended my use of the laptop by about a year (my wife's stock 500MHz model was retired well before mine, but when I would use it the machine's lack of speed was annoying enough I probably wouldn't have put up with it).
I'd bump this 1.33 up to 1.5 given the chance, although I'd undoubtably want to open it up and see if the cooling could be improved: this is the hottest-running chip I've ever owned, and as I type it's sitting at 146F/63.5C while doing some lengthy video encoding on my other monitor.