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G4 Cube Processor Comptibility?

C

corataylorx

macrumors newbie
Original poster
May 1, 2015
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Louisiana
So, after all the issues, Iv'e finally upgraded my Power Mac G4 Cube as much as I could. New AGP Graphics card, Maxed RAM, AirPort Card, and a Bluetooth dongle. (even a new PRAM Battery and installed a base fan)

Now, my question is, If I buy, say, an 800mhz CPU Card for the G4 Quicksilver, could I install it in my cube? I do have the know-how to do so. I'm just unaware if the socket would be compatible, and if the PSU would be able to handle the extra power draw. Not too worried about temps, I'll just slap some arctic silver 5 on it and install a bigger base fan.
 
corataylorx said:
Now, my question is, If I buy, say, an 800mhz CPU Card for the G4 Quicksilver, could I install it in my cube?
Click to expand...

Not really. The issue is the card overhangs the other direction vs the AGP CPU cards and would hit the IDE connector. If you're good with a soldering iron and dedicated, you could make it work, but it's far easier to use a different CPU. I believe the fastest OEM CPU is the dual 500MHz card from an AGP (compare pictures of this to the other CPU cards and you'll see it goes the other direction). I have one of these running at 550MHz in one of my cubes. All you have to do is tilt the inductor over so that it lays flat and find some kind of spacer (like copper) to thermally connect the CPU dies to the main cube heatsink.

Really, your best option is one of the aftermarket CPUs, like from newertech or powerlogix. These allow you to do a "VRM bypass" where the card is powered with 28v straight from the power brick and does not load the VRM card. Like so:

http://www.cubeowner.com/forums/index.php?showtopic=14768
 
The other issue you're going to run into with a QS card is that you'll have to supply an extra +12v from somewhere.

In addition, an 800mhz QS card will only run at 600mhz. Even the "granddaddy" dual 1ghz-assuming you could shoehorn both the card and an appropriate heatsink in-would only run at 750mhz.

I have a Sonnet 800mhz w/2mb L3 in one of my Cubes. It reuses the stock heat spreader/heatsink but does require a base fan(a good idea on all Cubes). This is a great processor.

I have another on the way with a 1.5gjz already installed.

I have both factory 450mhz and 500mhz Cubes. The 500 is interesting as a collector piece due to the lower production, but honestly isn't noticeably faster.
 
Without using a Cube G4 or a G4 designed for a Cube you risk burning out the VRM board. In theory, you can put any non-ZIF G4 CPU into a Cube and have it boot and use it.
 
Intell said:
Without using a Cube G4 or a G4 designed for a Cube you risk burning out the VRM board. In theory, you can put any non-ZIF G4 CPU into a Cube and have it boot and use it.
Click to expand...

A lot of people put heatsinks on the VRM FETs anyway. My dual 550 has run this way for years.

Suitable aftermarket CPUs seem pretty rare these days, but one thing you could try is a single 533MHz CPU. These are cheap, available, and usually 7410 chips so they use less power than the 7400. The 533 will nearly always do 550 reliably (5.5x on a 100MHz bus), and sometimes 600. It depends what you need, but assuming you're at 450 now, an easy 550 might be enough to get by.
 
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Heatsinks are not enough to prevent them from burning out. Non-Cube CPUs draw more power than the FETs are speced for causing them to burn out.
 
Thanks for all the replies guys. See, my issue is that CPUs from newertech or powerlogix are hard to find and expensive. But G4 cards are cheap. Like this one http://www.ebay.com/itm/Apple-Proce...230?pt=LH_DefaultDomain_0&hash=item4d319a8606

However I do see the clearance issue. And I don't really want to damage my cube by overloading it either. So, in this day and age, what are my options as far as a CPU upgrade for my cube?
 
corataylorx said:
TSo, in this day and age, what are my options as far as a CPU upgrade for my cube?
Click to expand...

1) single 550MHz (might get 600MHz, 7410 chip, change multiplier and drop in)

2) dual 450/500MHz (needs some customization, cooling, etc.)

3) aftermarket (rare, expensive, may need some customization)
 
flyrod said:
1) single 550MHz (might get 600MHz, 7410 chip, change multiplier and drop in)

2) dual 450/500MHz (needs some customization, cooling, etc.)

3) aftermarket (rare, expensive, may need some customization)
Click to expand...

Thank you. :)

I see no point in going up to 550. I mean it's just a 100mhz. Too much trouble to disassemble the cube just for that.

Which leads me to my next question. Is an overclock possible? Iv'e got fresh paste and a base fan installed. If not, if I find the 550-600mhz upgrade really cheap, I may just do it.
 
Intell said:
You can overclock stock Cube G4 by about 50Mhz-100Mhz.
Click to expand...

Sweet. That's about all I'd want to do. is this done at hardware level or software? I'm perfectly capable of doing it in increments, stress testing and the like. I've over clocked PCs, but have would I go about doing so on this cube?
 
To overclock a Cube you will have to solder small resistors on the G4 card. I think you can only do it in increments of 50Mhz.
 
Intell said:
To overclock a Cube you will have to solder small resistors on the G4 card. I think you can only do it in increments of 50Mhz.
Click to expand...

hmm.. I'll brush up on my soldering skills first xD thanks for all the input, guys. it's hard to find any information on the Cube for some reason. not even a full disassembly. had to figure it out myself.
 
You can follow overclock guides for a Sawtooth. Their CPU is nearly identical to the Cube's as far as overclocking it goes.
 
As far as disassembly, Google logic board removal and doing that will get it halfway apart(including the CPU). Removing the optical drive and hard drive will get most of the other half, leaving only the big center heatsink and the handle. They're actually not all that complicated once you get into them. You need a T8 and T10 screwdriver, and I think also a Phillips.

----------
corataylorx said:
Will do. I may just buy another one in case I screw it up. Thank you.
Click to expand...

I have a 450 that's yours for the cost of shipping.
 
Well I've actually already got the thing disassembled. I put fresh thermal paste on the stock cpu because there was basically none at all and I also installed a base fan. it's all back together now. it's pretty awesome. I like the cube a lot, so I've put a bit of money into the upgrades.
 
corataylorx said:
I see no point in going up to 550. I mean it's just a 100mhz.
Click to expand...

Well, it's also more than 20%, and I've seen single 533MHz cards go for $5 on fleabay. There's one going for $7 right now.

Fig1.jpg


From here:

http://www.xlr8yourmac.com/systems/DA_CPU_in_Sawtooth/DA_CPU_mods.html

http://www.xlr8yourmac.com/G4ZONE/sawtooth/SawtoothCPUdesign.html
 
I thought adding more info to this thread would be better than creating yet another one.

When it comes to Cube CPU upgrades, the Apple-made cards that physically fit a Cube are the single processor 7400/7410 cards, and the dual 7400 card from a Gigabit Ethernet tower. None of the Quicksilver or MDD cards will easily fit a Cube. The Digital Audio cards that will fit a Cube are the single processor 7400/7410 cards (which are nearly identical to the earlier versions).

So again, using Apple cards, the main options for a Cube are the single processor 7400/7410 cards (from the AGP, Gigabit Ethernet, and Digital Audio in speeds like 350, 400, 450, 466, 500, and 533MHz) and the dual 7400 card (450 or 500MHz) from a Gigabit Ethernet tower. In a Cube, these chips can be overclocked to 550, 600, and sometimes 650MHz.

To use the dual 450/500 in a Cube, the inductor on the CPU board needs to be moved, or a clearance hole cut in the Cube heatsink. Also, some sort of thermal connection needs to be made between the CPU silicon and the Cube aluminum heatsink (e.g. a piece of metal with suitable thickness).

I did one time see (back on cubeowner.com iirc) where someone installed a 733MHz 7450 CPU from a Digital Audio into a Cube. It required extensive modifications like cutting off the IDE connector, removing the airport connector, re-routing wires, and the same inductor and heatsink modification as for the dual 450/500, except with less room.

So many things are possible, but the main method to run a newer chip like the 7450, 7455, 7457, 7447, or 7448 in a Cube is to BGA solder one on, or simply use an aftermarket card. Some of the aftermarket companies like Sonnet, Powerlogix, Newer Technology, Giga Designs, Fastmac, OWC, etc. made upgrades specifically for the Cube. In many cases aftermarket cards made for the tower series can also be used in a Cube with minimal modifications, but heat and power can be a problem with this route. Try a search on "Cube VRM" to get an idea.

The Cube firmware will accept 7400, 7410, 7450 and 7455 CPUs, but will block later ones like the 7447, 7457, and 7448. The aftermarket companies made firmware patches to remove the block.

Here are more related threads:






 
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