Overclocking a Slot-loading iMac

The iMac DV ClockUp page was originally posted at <http://www.bekkoame.ne.jp/~t-imai/imacde1.html> and is no longer available there. We have adapted that information for the benefit of those who wish to overclock slot-loading iMacs.

sage iMac G3This may not apply to 500 MHz to 700 MHz iMacs that use the PowerPC 750CXe CPU, as they use a revised logic board. The original author is not known to us.

This infomation does not confirm stable operation. Please note that any modifications you make to your iMac are made at your own risk.

I analyzed how to increase the clock speed of an iMac DV. If you adjust the set of resistors labeled “R35” to “R42” on the logic board, you may configure the processor clock PLL.

First, remove the display connector cover.

Remove iMac bottom cover (6 screws).


Remove iMac bottom shield (6 screws).

Nonfigure the set of resistors labeled “R35” to “R42” on the logic board.

Resistor Settings

CPU Clock
PLLConfig
R35
R37
R39
R41
R36
R38
R40
R42
350 MHz
x3.5
x
S
S
S
S
x
x
x
400 MHz
x4
x
S
x
S
S
x
S
x
450 MHz
x4.5
S
S
S
x
x
x
x
S
500 MHz
x5
S
S
x
S
x
x
S
x
550 MHz
x5.5
S
x
x
S
x
S
S
x
600 MHz
x6
S
x
S
S
x
S
x
x
650 MHz
x6.5
S
x
S
x
x
S
x
S
700 MHz
x7
x
S
x
x
S
x
S
S
750 MHz
x7.5
S
x
x
x
x
S
S
S
800 MHz
x8
x
x
S
S
S
S
x
x
1 GHz
x10
x
S
S
x
S
x
x
S
  • S: mount resistor
  • x: remove resistor

Keywords: #overclockimac #overclocking

Short link: http://goo.gl/Pbsd1M

searchword: overclockimacg3

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