Here is my CPU card collection. :)

The front:
cpucardsfront.jpg

The back:
cpucardsback.jpg

There are both CPU revisions of 7455A and 7455B. Sometime will be doing some overclocking and see how they hold.

Probably overkill on owning all, but why not?

What's the fastest CPU card available without overclocking, for the MDD machines?

> What's the fastest CPU card available without overclocking, for the MDD machines?

http://www.sonnettech.com/publicfiles/pdfs/pdf_datasheets/encore_mdxg4duet_datasheet.pdf

Yea, Andreas_Wolf is right, as far as THE fastest is defenately that Sonnet Encore MDX. I just have the stock CPU cards that came with MDDs. I do not have any of the 867mhz or the 1ghz model CPU cards that some MDDs have. As far as the fastest one Apple gave the MDDs from them, it was a dual 1.42ghz card.

ah thanks.

I just finished the de-soldering work to overclock my 1.25GHz single G4 CPU module for my MDD PowerMac, but I am searching for all the correct links to information on the topic, before I turn my MDD back on again. I just want to double check that I have done every thing correctly, as it was a few days between looking at the documentation and finding the right tweezers to remove two of the resistors to obtain my 1.58GHz overclocking speed.

If all goes well, and the temperature does not increase too much with this overclock speed, I might then try an additional bump to 1.67GHz, but that will also require a small bump up of the voltage.

I have read that several other people have been successful in running the 1.25GHz G4 CPU modules (either single CPU, or dual G4 CPU's) at the 1.67GHz over-clocked speed, so it should work. It will depend on the performance of my cooling system with the Copper heatsink from the dual 1.42GHz G4 PowerMac and some good Arctic Silver thermal paste compound, coupled with the slightly lower cfm's of my Silent fan replacement.

If my current cooling equipment can cope with the heat of the overclocking speed of 1.58GHz well enough, then I might try the next bump to 1.67GHz.

amigadave,
Quote:

Nice! Keep me updated on how that 1.67GHz goes for you. I figured 1.5GHz should suffice. In the collection of 1.25GHz CPUs, I got both 7455A and 7455B. I think the Dual 1.25GHz 7455A card might not be as forgiving and have a hard time OC, whereas the Dual and Single 7455B cards will likely OC better.

Either way, have fun!

Hi !

i had few apple cpu powermac mdd cards...
I try to overclocked them :
A single cpu 1.25 overclocked to 1.5, at 1.58 it doesn't boot for me, but I saw some of these cards overclocked to 1.67.
A bi cpu 1 giga : can't overclock it (powermac doesn't boot)
A bi cpu 1.42 overclocked to 1.5... after the powermac doesn't boot.
Because morphos doesn't use the bi cpu, the single 1.25 is the best, I think. It is a shame mdd doesn't use the 7448 cpu used in the mac mini :( because it doesn't heat and I overclocked it until 1.83 ! (1.5 base).

Peg4A

> It is a shame mdd doesn't use the 7448 cpu used in the mac mini

1. The Mac mini has the 7447A (or more precisely, the 7447B), not the 7448:

https://morph.zone/modules/newbb_plus/viewtopic.php?forum=3&topic_id=6993&start=28

2. There are 3rd party 7447A CPU upgrade cards for the MDD:

https://morph.zone/modules/newbb_plus/viewtopic.php?forum=3&topic_id=8624&start=2

3. The 7447A CPU came to market only a year after the latest MDD (MDD 2003) was released. Between the 7447B and the more common older MDDs, even 3 years passed. So I don't think it's fair to call it a shame that Apple didn't use it for the MDD.

@Peg4a

Thanks for the information! Yea, I also agree the single 1.25 might best fit my needs. the dual 1.42 was quite hot on stock, whereas this 1.25 single runs cool with the copper heatsink. Either way, 1.5ghz would be good. Least I will have backup CPUs too if one blows up.

I managed to OC the single 1.25GHz cpu to 1.5GHz. So far so good. I didn't try to push it harder, but someday I will. At first I desoldered the wrong resistors (The ones right next to PLL 0-4.. And I went to install everything back together, booted the MDD and it still read 1.25GHz.. I looked at the photo and thats when I realized my mistake! I jumped the solder pads back and undid the correct ones, and now everything is correct at 1.5GHz.

I got two more MDD towers in which I will throw my other single 1.25GHz stock and do side-by-side comparisons on MorphOS.