1.42 CPU upgrade for original MDD?

Hi!

I have (had) a Power Mac G4 “Mirrored Drive Doors” (M8689LL/A) Dual-G4 7455 @ 1.0 GHz. It is the last and best Power Mac that is capable of booting Mac OS 9.

I wonder if it was possible to replace the processor module with the one from the 1.42 GHz FW800 model (which can be found on eBay these days).

Did anyone ever try that?
I found an article at xlr8yourmac.com, but it doesn't cover this particular case: http://xlr8yourmac.com/archives/jun04/062804.html#S17642

Thanks in advance, Andreas.

Power Mac G5 “Late 2005” DC 2.0 (M9590LL/A), Mac OS X (10.4.11), G5 Dual Core 970MP @ 2.0 GHz • PCIe • 16 GB RAM • ATI Radeon X1900 256 MB

Posted on Jun 30, 2009 3:08 PM

Reply
21 replies

Jul 4, 2009 11:39 AM in response to Mac User #330250

There are two classes of Processors for the Mirrored Drive Doors G4 Macs, and they do not follow the main distinction between the products -- Firewire 400 Vs. Firewire 800.

In the Mirrored Drive Doors models, processor speed is determined by a combination of the jumpers on the processor modules and the Bus Speed of the system into which the processor is installed.
• Install a processor intended for a faster Bus speed into a system with a slower Bus speed, and it will be clocked slower and run slower than expected.
• Install a processor intended for a slower bus speed into a system with a faster Bus speed, and it will be clocked faster -- in most cases so fast that it will immediately crash.

133 MHz Bus speed:
867 MHz dual w 1 MB cache (each processor) from Fw 400 model
1.0 GHz single w 1 MB cache from Fw 800 model

167 MHz Bus speed:
1.0 GHz dual w 1 MB cache (each processor) from Fw 400 model
1.25 GHz dual w 2 MB cache (each processor) from Fw 400 model
1.25 GHz dual w 1 MB cache (each processor) from Fw 800 model
1.42 GHz dual w 2 MB cache (each processor) from Fw 800 model
1.25 GHz single w 1 MB cache from "education only" 2003 model

-compiled from the Power Mac G4 (Mirror/FW800) Service Manual, General Information section.

Jul 2, 2009 11:33 AM in response to Nadav

As far as I know the system bus runs at 167 MHz on all MDDs/FW800s, except for the uni-processor low-end models (MDD: 867 MHz; FW800: 1.0 GHz; both run with 133 MHz system bus). The uni-processor 1.25 GHz MDD 2003 has also a 167 MHz system bus.

What troubles me: the headsink is different and the FW800 models are not Mac OS 9 bootable. Will the MDD Dual 1.0 GHz (mid model) accept the FW800 Dual 1.42 GHz (high-end model) CPU daughter card and still be able to boot Mac OS 9?

I read about the Sonnet 1.6 GHz and 1.8 GHz processor upgrade, that ships with an Open Firmware patch. This way the MDD/FW800 recognizes the new CPU and is able to boot Mac OS X and Mac OS 9.

In my case I wouldn't be able to update the firmware. I have an MDD with its original firmware. If I put in an 1.42 GHz CPU - will it be detected correctly? Will Mac OS 9 be bootable?

I don't know. The 1.42 GHz FW800 Dual CPU daughter cards are around $250,-- on eBay. This is too much to just buy something that might not work at all.

"It should work" is okay, but "I did that and it works" is better.

Anyway, thanks for the answer. It helped a little.
A.

Jul 6, 2009 10:38 AM in response to Mac User #330250

Hi,

I wanted to chime in on this discussion also because I previously owned an MDD. Great machine! I had a dual 1.25 and was considering just getting the dual 1.42 but then something stopped me and I wound up getting a G5 Quad and then trading that up for a 2008 Mac Pro. I might just get another MDD just to play around with it. What do you do with your G4 given this is now the age of Intel?

Jul 7, 2009 10:03 AM in response to Nadav

Hello Nadav!

I use it as my main desktop computer.

Since you asked, here is THE LONG STORY:
I had a PC (Intel Pentium III 600 MHz) before, but it was getting too slow. I also had and still have an IBM TinkPad R51 with a Centrino, Banias core (the first Pentium-M), that runs at 1.7 GHz and with 2 GB of RAM it is all I need for every day work.
Still, because I prefer a desktop computer over a laptop I hat to get a new one. I was thinking of a Dual-Core PC (Intel Core 2 Duo or similar). Lukily my sister knew of my plans and gave me an “old” MDD as a present.

That's why I now have it. And I love it!

What do I do with it? Firstly I had a lot of fun upgrading it. It came with only the original features, no extras like Airport (WLAN), Modem or Bluetooth.

So I installed a PCI expension card for USB 2.0. Then I upgraded the HDD to 500 GB and installed an ATAPI DVD Burner. The RAM was only 512MB (lukily on one single DIMM) so I got 3 more DIMMs and it now has its maximum of 2 GB RAM.

What do I use it for?
I run Linux on it. No problems whatsoever. Since Mac OS X 10.5 is also supporting the MDD I had it installed as well. But I rarely use it.

Only one problem with the PowerPC platform: any proprietary closed-source drivers or programs like the AMD/ATI video drivers, Flash Player and Skype don't work. Wine also doesn't run, which isn't much of a surprise. Running Windows is possible thru QEMU, but it is terribly slow.

There is only one program I really miss, which I regularly use on my ThinkPad: VirtualBox for trying and running other x86 operating systems.

Overall, for me the PowerPC platform isn't that much of a concern, as long as Linux supports it so well. In fact, X with KDE looks astonishing 100% the same as on my ThinkPad.

I know Mac OS X is leaving the PowerPC behind. Since I was never ever dependant on Photoshop, Microsoft Office and +you name it+ I will not miss Mac OS on my Power Mac.

For a few months I had to lend it to my sister again since her own Quicksilver was getting too slow for her, so we switched. But the Quicksilver is nice too.

Additionally I just bought a Power Mac G5 Dual Core 2.0 GHz – and yes, I also (try) to run Linux on it. I didn't have time to fully install and configure it yet, since my time is quite limited right now. But in the end this is going to replace the G4 MDD as my desktop computer.

So my plan right now is to upgrade the G4 to a Dual 1.42 GHz system, so my sister will be even happier with it. (And I will have an awful lot of fun installing the CPU card...)

Thanks for asking.

Jul 7, 2009 11:16 AM in response to Mac User #330250

Hi,

You mentioned you run Linux on the MDD. Doesn't the sound of those fans roaring cause you to re-consider doing that? When I tried installing Yellowdog Linux on my MDD awhile back, it would load up fine except for the fact that the power supply fans and case fan would roar very loud.

Or, do you recall that the linux distro you installed has a way to make the fans quieter?

Jul 8, 2009 2:29 PM in response to Nadav

I installed Gentoo Linux. But, if you ever heard of Gentoo Linux: you don't install it, you compile it.

Because the kernel is configured by myself and most of the packages (i.e. programs) are selected manually by myself, I had to digg deep into the system.

The fans roar loud on Mac OS X too. I wasn't able to tell any difference running Linux. The power management “windtunnel” is supported well enough to keep thinks cool and quiet (well, in G4 MDD terms).

Are you playing with the thought to run Linux on an old G4 of yours?

To be honest I never tried Yellog Dog Linux (YDL). My experiences are limited to OpenSUSE Linux (PPC is still supported by SuSE/Novell), Kubuntu Linux (not an official PPC version, but community supported) and Gentoo Linux.

The sound chip made problems at first, but it is now fixed using the snd-aoa ALSA module that comes with the kernel, 2.6.30 at least (recent version at the time of this posting). The sound was previously muted for CODEC chip TAS3004 with snd-powermac as well as with snd-aoa, but lukily got fixed recently.

Works like a charm. No problems except the missing proprietary stuff (Skype, Flash Player, …), in case you really need that…

Greetings, Andreas.

Aug 10, 2009 3:03 PM in response to Grant Bennet-Alder

I suspect that the only real difference between the two Dual 1.0 GHz CPU's is the necessary difference in the bus ratio settings.
with:
Aside from the difference in the bus ratio settings (which can be easily changed by hardware hackers), a major difference between the two Dual 1.0 GHz processors is the fact that all xserve G4 processorss have a 2 MB L3 cache on each CPU, while the *MDD Dual 1.0 GHz* processor CPUs have only 1 MB L3 cache each.

< Edited by Host >

Sep 15, 2009 10:12 PM in response to aarons510

To the original poster,

I currently have the exact machine you speak of running the dual 1.42 chip with 2MB L3 and booting OS9. You have to have the 167 bus series right before the FW800 models or before to boot OS9. I currently have the copper heat sink and the processor module installed in what was an MDD Dual 1.0 (1MB L3).

It boots and runs OS9 FAST. Problem here is graphics card. I ended up opting for an OSX level card (7800 GT flashed for mac) that doesn't have 3d hardware drivers in OS9. Other option is to get the NVIDIA Geforce 4 Ti which was the premiere card at the time these machines were new and does boot full 3d hardware in OS9.

Either way, noticeable performance improvement in OSX and OS9. The GF actually played WoW on it and leveled to 60 and then some before getting her imac 3.06 and smoking my best comp.

In fact I DO have the extra copper heat sink part that OWC sent with the module. I had gotten a brand new one off ebay before getting the module (and extra heat sink) from OWC. Contact me I guess if you are interested in it.

Sep 20, 2009 9:11 AM in response to Mac User #330250

The only thing that determines whether one of these machines will boot into OS 9 is whether the logic board is an MDD logic board (i.e., one with only FireWire 400 ports) or a FW800 board with, obviously, a FireWire 800 port. The former will boot into OS 9; the latter, i.e., those with a FireWire 800 port, will not.

The processor speed and the bus speed have absolutely nothing to do with it.

Note, BTW, that, +in official Apple terminology+, a FW800 is not an MDD even though it does have *Mirrored Drive Doors*. Go figure!

Sep 20, 2009 10:10 AM in response to ipcray

Hello.
I now have grabed a Dual 1.42 GHz processor card (original part from the fastest stock FW800) including its original copper heat sink.

I haven't had the opportunity to put it into place yet. But I'm glad to hear it will be capable to boot Mac OS 9 when installed into my MDD, originally a Dual 1.0 GHz with system bus speed of 167 MHz.

My graphics card is also original stock ATI Radeon 9000 with 64 MB of VRAM. I've neved used Mac OS 9 on it before except in Classic mode, but I hope it's supported including 3D accelleration.

My sister uses it for DTP and has a couple of (older) software running on it. I've now bought a version of Mac OS X 10.5 to keep the machine updated and fit for the internet (concerning security fixes).
The setback is of course the missing classic support which will make a dual boot setup together with Mac OS 9.2.2 necessary. I sure hope I can acomplish it.


One thing is not quite clear to me:
What is this OWC heatsink you are talking about? I've never heard of a Dual 1.42 GHz processor upgrade by OWC, although I just tried a Mercury Extreme 1.4 Ghz single in an older Gigabit Ethernet, originally 400 MHz. I tried this processor upgrade in a Quicksilver too, but reverted to the original Dual 800 MHz as it seemed still faster than the single 1.4 Ghz.

Cheers,
Andreas

Sep 20, 2009 10:06 AM in response to aarons510

Thanks. I've already got the processor+heatsink, and will install it eventually.

I know that the model is called either MDD or FW800, but technically they are almost identical. The only difference is the FireWire port and, obviously, the compatibilty to Mac OS 9. I'm not an expert but I'd say the latter is due to a different firmware only. So the difference is more of a political decision by Apple than a technical barrier.

Cheers,
Andreas.

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1.42 CPU upgrade for original MDD?

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