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View Full Version : Quicksilver processors compatible with Gigabit Ethernet G4?




coldcaption
Jul 6, 2011, 09:40 PM
Howdy! I have a Gigabit G4 with a 400 MHz processor running 10.3. Things are dandy enough, but faster processors seem to go for very little on eBay. It's easy enough to tell which ones will certainly work with the Power Mac, but I can't find many resources to tell me whether or not I can use processors from Quicksilver (or Digital Audio!) G4s. In pictures they seem like they'd fit, but their PCBs do have a bit 'extra' on them that isn't present on the stock one I've been using. I'd appreciate any help!

Edit: Also, would it be wise to use my current heatsink with dual-processors? Only half of it is actually heatsink (other half is flat metal); but from what I can gather, the processor is in the middle of the PCB anyway.



840quadra
Jul 6, 2011, 10:56 PM
Hi,

I have a digital audio with a quicksilver processor installed. the DA has a 133 MHz bus like the quicksilver, but lacks the 4th mounting screw that provides an additional 12v power source for the quicksilver processor. On older systems like ours, you need to run a wire to that mounting location, to provide the quicksilver processor the additional power. Also keep in mind that any Quicksilver or digital audio processor will run at a reduced processor speed on your system due to the 100 MHz bus speed.

in this post I was discussing the differences in processors, and I have an image included showing a quicksilver processor, next to an older one. Our older systems use the 3 mounting screws that are in a < pattern (sideways V), the point you need to run 12 volts to is in the bottom left corner on the larger processor in the image shown in the post below.

http://forums.macrumors.com/showpost.php?p=10950946&postcount=8

You will need a dual processor heatsink / fan setup, as the one you have will not contact or cool both processors.

coldcaption
Jul 7, 2011, 12:39 AM
Ah, that was extremely helpful; thanks! I assume, then, that G4 processors up to ones from the Digital Audio machines would be immediately compatible? I'm not sure what I'll go with yet, but it's good information to have. Also, could you please detail a bit how you got the 12V feed to the extra screw? I want to know what you did to have it working so it wouldn't disconnect or otherwise be a problem, as well as where you drew it from. Thank you so much!

Cox Orange
Jul 7, 2011, 05:20 AM
this is interesting, since it is not covered here http://lowendmac.com/mail/0803mb/0306.html#2 (restrictions in spapping G4 CPUs).

I recently wondered, if a last generation Quicksilver and first gen. MDD would be interchangeable, since the BUS-speed is the same and the other MDD models all seem completely different by looking at the specs. In fact I wondered, if the first MDD, was just a Quicksilver in an MDD-case.

840quadra
Jul 7, 2011, 07:20 AM
Ah, that was extremely helpful; thanks! I assume, then, that G4 processors up to ones from the Digital Audio machines would be immediately compatible? I'm not sure what I'll go with yet, but it's good information to have. Also, could you please detail a bit how you got the 12V feed to the extra screw? I want to know what you did to have it working so it wouldn't disconnect or otherwise be a problem, as well as where you drew it from. Thank you so much!

You are going to need to tap into power from one of the Molex Power Supply cables intended for Hard disks or CD / ROM drives.

http://www.excaliberpc.com/images/resources/593611/29ed69526792460984ad3ccd03189a60.jpg

The yellow wire is +12v, and is the wire you need to somehow tap into, and run to the 4th screw hole. In my case, I had a dead Auxiliry CPU fan for a PC, that plugged directly into the molex power supply source. I then cut all but 1 of the wires free from the fan, and used the remaining wire as my power for the CPU, putting it into an eylet that I could bolt to the 4th mounting hole on the Quicksilver CPU

http://shop.gotellispeedshop.com/images/1294771841269-1361935945.jpeg

I used a simple PC case screw, and a nut that fit the threads ( I have stuff like this lying around ;) ) and attached it to the 4th mounting hole of the Quicksilver CPU.

You need to be careful to ensure this 4th screw and nut does not contact the Motherboard, or touch the heat-sink. If it does, it can short out, causing bigger problems. So put a small square of adhesive backed rubber sticky pad on the logic board near this 4th point, and modify the CPU heat-sink if needed.

You may also have to do light case modifications to allow for the Quicksilver heatsink to clear your CD-ROM / ZIP drive cage. You May be able to keep your old heat-sink depending on the speed of processor you go with, to avoid this though.

this is interesting, since it is not covered here http://lowendmac.com/mail/0803mb/0306.html#2 (restrictions in spapping G4 CPUs).

I recently wondered, if a last generation Quicksilver and first gen. MDD would be interchangeable, since the BUS-speed is the same and the other MDD models all seem completely different by looking at the specs. In fact I wondered, if the first MDD, was just a Quicksilver in an MDD-case.

I guess I don't know what that guy is on about for part of that post, but the only reason you would need to do any electrical modification to the processor, is to change it's multiplier to match the older systems 100 MHz bus speed. Bolted down, and given the correct power, the CPU will work fine, but be slower on the older 100 MHz Bus. You can change resistors around to increase the multiplyer on the CPU to a higher rate, but I don't know which resisters you would move / change to do this sadly :( .

Without modification you can calculate what a CPU from a 133 MHz Bus PowerMac will run, on a 100 MHz Bus system

Say we are working with an 800 MHz Quicksilver Processor
(800Mhz * (100/133)) = 600Mhz

I have zero experience with the MDD systems sadly. I am not sure about processor compatibility with those. There are quite a few write-ups on installing Quicksilver CPUs in older systems, but I have never seen one on a MDD CPU. :confused:

coldcaption
Jul 7, 2011, 11:43 AM
Wow, pictures and everything! Thanks so much for all of the help; I'll almost certainly be giving this a try. At best, it seems I can get about 751 MHz with my bus speed using a 1 GHz processor. Considering that I'd be moving up from 400 MHz and almost certainly getting two, that'd be a pretty good speed boost! I'll certainly come around again if I need more help; I'm getting much more so far than I've gotten from Apple's support forums in the past.

666sheep
Jul 7, 2011, 01:39 PM
840quadra: you have DA, Sawtooth/GE w QS CPU mod is slightly different. It requires one more important thing (except additional 12V feeding OFC):
- desoldering ATA33 connector off logic board (otherwise QS CPU won't precisely fit in CPU socket - QS daughtercard is a little longer than Sawtooth/GE)

I have few links with details of this mod , but all are seem to be dead now.

I've done something like this few years ago (of GE) and I've reached 960 MHz with 733 QS CPU @120 MHz bus (yes, sawtooth/GE can do it ;))

Unfortunately I haven't done more pics of the whole mod stages, but there are few for reference:

GE CPU (this particular OC'ed, with added fan) - see space between original CPU and ATA33 connector

http://i52.tinypic.com/34gr9dg.jpg


QS 733 CPU in GE - see where left edge of QS CPU ends in comparison to original GE CPU

http://i54.tinypic.com/29xztvt.jpg

12V from PSU soldered to QS CPU (free mounting hole)

http://i53.tinypic.com/2rfqz9v.jpg


You can see my machine's Xbench @960/120 MHz score here (http://db.xbench.com/merge.xhtml?doc2=331462)


OP, if you are well skilled in soldering, get 933 2MB L3 CPU from QS and this is IMHO the best of QS CPUs for GE. I've OC'ed few to 1066 MHz without problems with stock voltage. And 2MB L3 does its work very well.
Any dual from QS will be more problematic heat wise. GE cooling is slightly different than QS.

840quadra
Jul 7, 2011, 02:39 PM
840quadra: you have DA, Sawtooth/GE w QS CPU mod is slightly different. It requires one more important thing (except additional 12V feeding OFC):
- desoldering ATA33 connector off logic board (otherwise QS CPU won't precisely fit in CPU socket - QS daughtercard is a little longer than Sawtooth/GE)

<Snip>



Thanks for the details on this. I actually do know about that issue, but had TOTALLY forgotten that step, despite helping desolder a friends connector years ago! :o

The processor location on the Digital Audio is in near the exact same location as the Quicksilver, while the Sawtooth, and Mystic systems had it located much closer to the ATA connectors (as shown in 666sheep's pictures). Since it's been a while since I had worked with one of those G4 systems, I totally forgot :( .




coldcaption
Your project is slightly more complicated because of this, but still doable if you are up for the challenge. The other option is, getting a Digital Audio Logic board, which would give you the faster bus speed, 4x AGP slot, and one extra PCI slot. The only issue here is that I believe you would need a new power supply that supports that system.

On eBay currently you can get a DA logic board for $35, and since it takes the same power supply as the logic board you currently have, should be a direct replacement with a slightly higher celing than what you currently have.

Though personally, I hate retiring any piece of Apple hardware that is in good working order :o . Your GE Logic board is in good working order, and has a purpose!

coldcaption
Jul 7, 2011, 03:54 PM
I've never done anything with soldering/desoldering before. I'm comfortable enough with computer hardware to be able to do it for sure, but I don't want to make those kinds of permanent changes to my hardware in case I ever want to go back over the changes. Out of curiosity, how was the overclocking done? I've looked into it and seen that it requires some soldering as well, but never got the full rundown.
Getting a DA logic board isn't a bad idea, since I wouldn't have to modify it to get a new processor up and running. Though I agree; I'd then have to find something to do with the GE board! I've already been trying to come up with what I might do with the 400 MHz processor once it's out. I may look into simply getting a DA and putting this to work for some other additional purpose, since the cost of parts would add up after getting a new power supply, logic board, and processor; and an additional PCI slot would have nowhere to go in the GE's case.

Oh, and; wouldn't desoldering that connector have some adverse effect? It looks to me like it runs up to where the optical drive is, and I wouldn't want to lose that functionality!

zen.state
Jul 7, 2011, 05:03 PM
My NewerTech G4 upgrade CPU in my Sawtooth has similar wires coming out of it with a female molex on the end. It works in the Sawtooth through to the Quicksilver. Also has built in switch jumpers for proper clocking in the different bus speeds.

Too bad the stock Apple daughter cards have to be soldered to change the clock rate. It might well be possible to solder on a switched jumper block if everything lines up right on the bottom.