Was browsing http://www.xlr8yourmac.com and ran across this interesting comparison:
http://www.xlr8yourmac.com/systems/1ghz_g4/1_ghz_G4_vs_Athlon_1_6Ghz.html

Take a look and you’ll see that an overclocked G4 pretty handily outpaced an overclock Athlon at half again the clock speed. I’d venture to say that a 1 GHZ G4 could easily outpace Intel’s 2GHZ P4s after looking at those results. It seems apparant, to me at least, that the way Intel and, to a lesser extent, AMD get the MHZ numbers is by gross overclocking. Why else would they need all of that heatsinking and fans?

The question is, if all it takes is for Apple to bury the G4 in a ton of heatsink, why not get the MHZ numbers like Intel does?

There’s two benefits I see from doing so;

1) PPCs are already designed to be faster than a Intel Pentium at the same clock speed. By matching Intel in MHZ the realized speed of a Mac would likely double. (Maybe triple?)

2) No more PR about the MHZ Myth.

So, why doesn’t Apple overclock G4s?

<font size=-1>[ This Message was edited by: VSeward on 2001-08-29 08:31 ]</font>

I am not sure.  I for one have avoided it on my machine due to the warrantee.  Maybe after it expires.

Chuck

Hi,

I suspect the main reason Apple/Motorola don’t overclock the chips is due to reliability. I believe that chips when produced are tested at the highest Mhz speed - i.e. 867Mhz - if they pass they are used - if they fail then they get tested at the next speed down.

That way I suspect that any machine will have a processor in it that has already been tested at higher speeds and has failed so overclocking may be asking for trouble!

This is rumour however so I could be talking rubbish….

James Mackay

Edited for spelling! JM

<font size=-1>[ This Message was edited by: Maccers on 2001-08-30 06:41 ]</font>

On 2001-08-30 06:19, Maccers wrote:
Hi,

I suspect the main reason Apple/Motorola don’t overclock the chips is due to reliability. I believe that chips when produced are tested at the highest Mhz speed - i.e. 867Mhz - if they pass they are used - if they fail then they get tested at the next speed down.

That way I suspect that any machine will have a processor in it that has already been tested at higher speeds and has failed so overclocking may be asking for trouble!

This is rumour however so I could be talking rubbish….

James Mackay

Edited for spelling! JM

<font size=-1>[ This Message was edited by: Maccers on 2001-08-30 06:41 ]</font>

I thought this too, at first, but if you think about the fact the Intel seems to consistently push their CPUs to the brink you have to wonder if Motorola isn’t throttling back the PPC for some hidden reason.

The thing is that sites like the one posted earlier prove that the G4 could make 1GHZ, which seems to be the magic number currently for speed. G4s, like P4s, will operate at the higher clock speeds if cooled properly. If that’s all it takes then why don’t Apple just cool the suckers and claim 1GHZ + clock speeds like Intel/PCs do?

Does anyone remember the first G4s? Almost immediately upon their release, Apple had to downscale them by 50Mhz because Motorola was having trouble with ‘cache coherency’, which, if you don’t have it, you either have to run without the cache (sacrificing any actual speed garns as memory is always running quite a bit slower than the CPU) or your processor ends up smoking crank (happily feasting on garbage).

Pentia run at higher clock speeds because what is actually running is the “ROP” layer, which is basically a hidden RISC processor emulating the i86 code. Rumor has it a P4 running at the same clock speed as a P3 will lose the race because of the way they had to redesign the CPU internals to handle the higher clock speeds. Note that Intel’s new architecture 64bit CPU (which bears some passing resemblance to PPC Architecture), currently known by some as “Itanic”, is foundering around the 800Mhz mark itself.

Also, do a lot of research on over-clocking your G4. I have seen in more than one place that although the CPU is in a ZIF socket, the motherboard will not allow it to run faster than the OEM setting.

Well, apparently the guy in the link I posted was able to push an 887MHZ G4 to 1GHZ with no apparent problems.

But this is off the subject. It IS apparent that the G4 can run faster than what Apple and Motorola is giving us. If someone can overclock the G4 with no real problems than why don’t Apple sell them overclocked already?

I’m going by the assumption that there is no real technical problems with pushing the MHZ higher. There may very well be, but if that’s the case anyone overclocking a G4 would run into those problems, I assume.

Of course, there’s the heating problem, but a judicious use of fans and fins can take care of that.

So, I asks again, WASSUP?

I would suspect the issue is volume. Sure, some of the G4 chips can run at 1 Ghz, but can Moto crank out enough chips at that speed to meet demand? It’d be a real shame if Apple had to announce a 1Ghz G4 and then have to do the speed dump again because they didn’t have enough chips to meet the demand.. I figure Steve is being cautious after the last time he jumped the gun and announced a chip speed that Moto couldn’t produce.

I also read the report on the overclocking of the 867to 1 GHz, and not only did this person loose any support from an authorized Apple service center regarding the internals of his machine. What the profit he made, he can brag about his 1 GHz G4, but how many others will try and end up with either a fried motherboard or a dead G4. Overclocking these G4’s requires soldering on the processor card. Something I wouldn’t do even if the warrenty had run out.

On 2001-09-02 18:03, Morto wrote:
I would suspect the issue is volume. Sure, some of the G4 chips can run at 1 Ghz, but can Moto crank out enough chips at that speed to meet demand? It’d be a real shame if Apple had to announce a 1Ghz G4 and then have to do the speed dump again because they didn’t have enough chips to meet the demand.. I figure Steve is being cautious after the last time he jumped the gun and announced a chip speed that Moto couldn’t produce.

There’s some truth there, Morto. There are a lot of environmental parameters that must be met for a CPU to operate at whatever speed. Here’s my slant on this.

I overclocked my 6100 a while back. It was easy to do, actually. When overclocking one of the things you are supposed to pay attention to is stability. So the software and instructions that came with my overclocker had me test my system at the max speed (I think it was 100mhz) then back down the speed until I found a stable rate. (I think it stablized around 80mhz. It was a 601 66mhz.) It sounds like the guy that did the 887mhz overclocking performed a similar process. True, some chips will be more stable at the higher speed than others, but he seemed to have no problem getting his 887 to 1 gig.

So, my point is that pushing the current crop of G4s to 1GHZ seems doable. I know IBM’s chips will hit 1 GHZ, they’ve had G4s running at that speed for some time now and can produce them in reasonable volume (at least, that’s what I heard. ), so we really should be seeing 1 GHZ machines out there. Why don’t we?