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macosx1058
Aug 31, 2012, 09:31 PM
Can i upgrade a single 1GHz model to a dual 1GHz or a dual 1.25GHz cpu with no issues?



Intell
Aug 31, 2012, 09:32 PM
Possibly. But you need to be able to change the fbus speed on the CPU or logicbaord, put in faster ram if changing the speed up, and get a better heat sink.

macosx1058
Aug 31, 2012, 09:36 PM
Possibly. But you need to be able to change the fbus speed on the CPU or logicbaord, put in faster ram if changing the speed up, and get a better heat sink.

how would i change the FSB? cant i just plug it in and boot it up? it already has the same heatsink found on the dual 1.25ghz cpu

Intell
Aug 31, 2012, 09:40 PM
There are three heatsinks used on the FW800 MDD. A small aluminum one, a large aluminum one, and a large copper one. All singles have the small aluminum one. To change the fbus speed, you'll have to move some resistors via soldering the CPU daughtercard or the logicboard. But before you do that, you have to find the correct ones and set them in the correct places.

macosx1058
Aug 31, 2012, 09:55 PM
There are three heatsinks used on the FW800 MDD. A small aluminum one, a large aluminum one, and a large copper one. All singles have the small aluminum one. To change the fbus speed, you'll have to move some resistors via soldering the CPU daughtercard or the logicboard. But before you do that, you have to find the correct ones and set them in the correct places.

i have the heatsink with thin flexable aluminum fins im not good at nor have equipment to do resister work just want to plug it in and boot it up

Intell
Aug 31, 2012, 10:00 PM
That's the single G4 heat sink. It does not have enough heat transfer abilities to be able to cope with a dual MDD G4 very well and will lead to overheating. It is very unlikely, but a dual MDD G4 might work with a simple swap in a single MDD.

macosx1058
Aug 31, 2012, 10:01 PM
That's the single G4 heat sink. It does not have enough heat transfer abilities to be able to cope with a dual MDD G4 very well and will lead to overheating. It is very unlikely, but a dual MDD G4 might work with a simple swap in a single MDD.

u mean lb swap or cpu swap?

Intell
Aug 31, 2012, 10:05 PM
CPU swap.

macosx1058
Aug 31, 2012, 10:15 PM
CPU swap.

will the dual 1ghz from a fw400 work? and how much of a preformance increase will i see from single to dual 1ghz?

Intell
Aug 31, 2012, 10:24 PM
No, it has the faster fbus. The only dual MDD G4 that has the slower fbus is the dual 867 MHz.

macosx1058
Aug 31, 2012, 10:33 PM
No, it has the faster fbus. The only dual MDD G4 that has the slower fbus is the dual 867 MHz.

so im pretty much SOL on a processor upgrade huh? if i get a Dual 1.25 and install it will it be reduced to dual 1GHz? BTW if it matters i got it with 1 stick PC2100 256MB RAM (im assuming factory issue) along with a 512MB PC2700 OWC stick and i added a PC2700 256MB stick giving me 1GB.

I read on another mac forum site of someone getting a MDD with a 1GB Stick installed however i have not seen anything about this working nor have i got 1GB to test with.

Lil Chillbil
Aug 31, 2012, 11:24 PM
If your up for the challenge you could try to overclock it a little bit Its no cpu swap but if 1ghz is not suiting your needs it will help with performance to up it to like 1.1-1.25ghz at a stable speed

macosx1058
Aug 31, 2012, 11:47 PM
If your up for the challenge you could try to overclock it a little bit Its no cpu swap but if 1ghz is not suiting your needs it will help with performance to up it to like 1.1-1.25ghz at a stable speed

1GHz is just fine for me but my eMac is also 1GHz but my eMac is my secondary computer this PowerMac is replacing my primary AMD 2.40GHz 2GB RAM system this thing hardly gets hot on all day long its current CPU temp is 105.3F my AMD never ran this cool :D

archtopshop
Sep 2, 2012, 09:43 AM
Can i upgrade a single 1GHz model to a dual 1GHz or a dual 1.25GHz cpu with no issues?

A 1.25GHz Dual board from a FW800 will work fine on any FW800 motherboard, no matter if its speed is 133MHz or 167MHz. However, on a 133MHz motherboard it will be underclocked and function as a 1.0GHz Dual processor machine. If one wants the full 1.25GHz Dual speed then a resistor on the back of the motherboard (not cpu daughtercard) must be removed.

I performed this upgrade on my wife's single 1.0GHz FW800 about a week ago. It's an easy, plug and play swap. Removing the resistor is another matter--they are extremely small. I plan to do this at some point, but for now my wife is happy with the already noticeable speed increase.

As far as the heatsink is concerned, the heatsink with the many flexible fins is the one which originally shipped with the FW800 1.25GHz Dual machine. The copper one came with the 1.42GHz Dual. As far as I know, the other heavier aluminum heatsink came with the original MDD's and the FW800 single 1.0Ghz model. My wife's 1.0Ghz single came with this one, but I changed it out for the flexible finned one which came with the dual daughtercard I purchased on eBay.

Every FW800 1.25GHz Dual I have ever seen (and that's more than a few) have had the flexible finned heatsink. While it may not look as substantial as the solid aluminum finned one, because it has many more fins it should provide better cooling. In any case, it came this way from the factory in my 1.25GHz Dual FW800.

As an aside, my wife's FW800 operates 10 degrees F cooler than mine. I assume because it is running at the slower speed. The machines are using Tiger 10.4.11 and setup identically.

As always, I am not trying to dispute anyone else's posts or opinions on this forum, just relating my own experience. Oh, I see I have to change that signature now.:D