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Gigabit Ethernet logicboard with Quicksilver CPU

jholt5638

Well-known member
I just ordered a Quicksilver 733MHz Single CPU I plan on installing it in my Gigabit Ethernet Logicboard. From what I have read it should work as along as supply a 12V to the 4th mounting hole. It also says that normally the heatsink interferes with the second ata connector but since I have the board in a ATX case other sources say it should be fine. I am comfortable with changing the jumpers on the cpu card but should I instead use the firmware hack to overclock the Giga's system bus to 133MHz? I am running pc133 RAM already so there should be no problem there. 

Do I have the basics of what needs to be done? 

1. modify ether the Firmware to overclock the system bus to 133MHz or adjust the multiplier to x8 on the CPU

2. add a 12V rail to the 4th mounting hole of the CPU.

Anything I missed?

 

MacJunky

Well-known member
The issue is that the ATA connector is in the way of the wide CPU card itself. The QS heatsink is a different issue and would normally interfere with the CD/ZIP bays in a Sawtooth/GBE case.

For the purpose of this conversation, Sawtooth and Gigabit Ethernet are effectively the same as far as I recall.

12v to the additional mounting hole of QS modules is correct.

I am not aware of a firmware modification that actually OCs the bus, but it has been a long time. You can add a DIP switch to a spot near the RAM (visible in my pic) but at least with the Sawtooth, idk about GBE, you are not likely to hit a stable 133 according to the internet. Though tbh I only just added the switch to my Sawtooth and have not tested it yet.

In your case you are going to have to hack off the ATA connector. you could solder wires in it's place though if you really need it. Be really cool to find one that we could just solder directly to the underside of the board after stripping the old one off but it is not as simple as just flipping a regular connector around.

For anyone else considering, you might look at overclocking a 533MHz Digital Audio CPU?(if you are /really/ inclined to push things) http://www.xlr8yourmac.com/systems/DA_CPU_in_Sawtooth/DA_CPU_mods.html

100_7048.2.jpg

 
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jholt5638

Well-known member
Ok so I will have to remove the secondary ATA connector and ether solder a extension to the board or just move the Optical drive to the slave position on the primary. Probably cut the connector and  just move the drive would be the easiest solution. I'm not confident enough in my solder skills to start poking around on the logicboard doing the ATX to GBE PSU mod and Overclocking my 400MHz to 450MHz was nerve wracking enough lol

 
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jholt5638

Well-known member
what's the best way to remove the connector? Simlar to the Beige G3 to ATX mod to remove the DB15 video connector,

cut the top pins bend it cut the bottom row?

 

MacJunky

Well-known member
Just as a general reference for anyone interested in G4 towers: http://www.outofspec.com/frankenmac/wire.shtml

Also, perhaps you want to toss in a PATA or SATA card to regain ports lost?

As far as removing the connector some would snip, some would pull the black plastic off and desolder the individual pins, some would heatgun the whole thing. It depends what tools&experience you have and what you feel comfortable with.

 

jholt5638

Well-known member
All I have at my disposal is a 15W soldering iron, rosin core solder, and wire stripper/cutter so cutting looks like the way I will go.

I found that site before when I was looking for the proper pinout for my ATX PSU to GBE I ended up it and another source so I don't have a wall wart coming out of my case. I took a +12V rail and the +5V Standby rail with a couple of 50V 1A PNI Diodes and wired it up to the +28V pin on the GBE logicboard works good though it prevents me from using ADC monitors and Firewire would be iffy according to the information I read. I may still switch to using the wallwart if I ever find a decent priced original iSight camera 

 
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jholt5638

Well-known member
I also need to get around to actually mounting it properly. The case I am using only one hole lined up and everything is where it should. So for now I have the board secured to the case by that one mounting hole the rest of the standoffs are threaded into a piece of cardboard and the board is mounted to that

 

MacJunky

Well-known member
I would really suggest drilling some holes in the motherboard tray of your case. To save the hassle of tapping holes, you can stick nuts on the back of standoffs. If you are using a drill rather than a drill press, your holes are not going to be the right size, shape, or location anyway. Brass standoffs secured by nuts will offer a little leeway in the slightly larger than desired holes.

On a side note I have been playing with my Sawtooth board and a 800MHz Quicksilver CPU card. I can only get the FSB up to 120MHz so at the 8x multi I am stuck at 960MHz. Cinebench crashed on the first run then completed a second run for massive 0.11pts. It hit 0.09pts at 120FSB 840MHz. I did not run cinebench at 900MHz, because who has the time? Pretty clear where the score would land anyway. I have xbench 1.3 results somewhere too.

I suppose I could toss it in my DA board and see what happens, but it looks like it might need a volt mod to be stable at 960MHz or higher and does not have much in the way of multipliers anyway. (never mind having no L3 cache)

Anyway, back on topic. How are your attempts going? Please keep us updated.

100_7054.2.jpg

 
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jholt5638

Well-known member
Right now just waiting on 733 get here to install. I did decide to cut the ide connector off and replace with a sonnet tempo ata pci carf

 

jholt5638

Well-known member
Well looks like I'll have to get someone to cut the GBE heatsink. doesn't look like it will fit the QS CPU card as is

 

MacJunky

Well-known member
You mean on just one side? Try a hacksaw, it is just aluminum is it not? Make sure you stick a fan on the heatsink afterward though. :p

If you do cut it, make sure you look at it from the side once mounted to check for gaps between the die itself and the contact area of the heatsink. It is okay if the spacer around the die is not making contact, that just helps prevent the die from being crushed if the heatsink is not sitting flat.

 

jholt5638

Well-known member
Some progress while waiting on the CPU arrive, I went out and got some standoffs that had screws for both sides instead of the ones that you thread into the mainboard tray from Radio Shack and replaced the cardboard. Still only secured to the tray with one screw but at least it looks better. Added a intake fan and cut some slots on the side panel of the case directly over the CPU.

 

Quadraman

Well-known member
Can this even be done? The Gigabit Ethernet uses a 100mhz bus, the Digital Audio and Quicksilver use 133mhz bus. If it does work, you won't get 733mhz from it because 733 isn't a multiple of 100. You'll get 550 at best, if it works at all and if 550 is all you're going to get then you'll be better off with a dual 450 or 500 CPU card that was made for the Gigabit Ethernet.

 
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jholt5638

Well-known member
I have this working no problems, just changed the resistors on the cpu to 7.5 from 5.5 and added the 12V very stable

 

Quadraman

Well-known member
Please re-read the thread, or perhaps check a search engine.

It is very doable.
It still seems like a lot of trouble when a dual 500 CPU is like $20 now and a whole QS machine can be had for $50 plus shipping.

http://www.ebay.com/itm/PowerMac-G4-M8493-733MHz-640MB-RAM-NO-HDD-/231378851401?pt=Apple_Desktops&hash=item35df411649

$39.00 + $10 shipping, bring your own hard drive.

Oh, and you do know the 733 Quicksilver CPU has no level 3 cache, right? A 733 Digital Audio CPU is faster because it has the cache.

 
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