Dual 867

[MacRumors]

brett posted the following information page after he clocked his dual 800 mhz G4 to a dual 867... fastest mac on the planet.

Synopsis: I tried to overclock my August 2001 Power Mac dp800 to 867 and 933. After some trial and error with the pll banks, it has worked fine reporting at dp867.

[Megaquad]

is it possible to overclock dual 800 to 1 GHz,stable?

[Megaquad]

i read it now it isn't possible

You might be able to clock it faster but in the long run the dual will come out above.

[ThomasB]

How would a Dual 800 be faster than a Dual 867?

sorry didnt realize it was a dual 867 thought it was only a single processor.

Where did you get a dual 867 and a 900? Did you build them or upgrade them from other stores, not apples??

[ThlayliTheFierce]

Did you read the article? He overclocked a dual 800.

[Xistor]

I wonder why it didn't work at 933.. perhaps it wasn't really 933 that it was set to.. I wonder if the author used a frequency counter to double check the system clock on that one.. then again, there are few *cheap* frequency counters that can count something that fast.. Most o'scopes out there can't even see a signal that fast.. unless they are at the most outrageous end of expensive digital kinds.

[brett]

hi,

i did try dual 933 and got a bong but no boot process. i'm pretty sure it was 933 because once at 867, the pll scheme demands a reversal of each non-apple-populated jumper. in any event, i will try 933 again when i have some time. dp867 works great -- no stability issues. sorry the page wasn't clearer on 933 but i threw it up before the holiday weekend. also, i don't have a handheld clock tool, but my page has like 7 utilities, each of which report 867.

brett.

Originally posted by Xistor
I wonder why it didn't work at 933.. perhaps it wasn't really 933 that it was set to.. I wonder if the author used a frequency counter to double check the system clock on that one.. then again, there are few *cheap* frequency counters that can count something that fast.. Most o'scopes out there can't even see a signal that fast.. unless they are at the most outrageous end of expensive digital kinds.

Chips are manufactured on wafers. A wafer contains a quantity of chips, typically a couple hundred. Some of the resulting chips will be able to run at higher clock rates than others, due to slight inconsistencies in the manufacturing process. The manufacturer will test a batch of chips to see if they run okay at a given speed, often not bothering to see if they'll run faster. Apple orders some huge quantity of 800 MHz G4's, Motorola just ships any that work at 800. Some of those might have worked at 867 or 933, but they were never tested.

Testing a chip at a higher rate won't hurt it, as long as it's kept cool enough.

-Jake
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chown -R us:us yourbase

Originally posted by Xistor
I wonder why it didn't work at 933.. perhaps it wasn't really 933 that it was set to.. I wonder if the author used a frequency counter to double check the system clock on that one.. then again, there are few *cheap* frequency counters that can count something that fast.. Most o'scopes out there can't even see a signal that fast.. unless they are at the most outrageous end of expensive digital kinds.

Chips are manufactured on wafers. A wafer contains a quantity of chips, typically a couple hundred. Some of the resulting chips will be able to run at higher clock rates than others, due to slight inconsistencies in the manufacturing process. The manufacturer will test a batch of chips to see if they run okay at a given speed, often not bothering to see if they'll run faster. Apple orders some huge quantity of 800 MHz G4's, Motorola just ships any that work at 800. Some of those might have worked at 867 or 933, but they were never tested.

Testing a chip at a higher rate won't hurt it, as long as it's kept cool enough.

-Jake
---------------
chown -R us:us yourbase