Processor Swap in G4 Cube

[EmilioCube]

I want to upgrade the stock 450mhz processor on my Cube, but I do not want to spend 200 bucks on a single 1Ghz Sonnet upgrade on eBay. So my cube has a 7400 G4 and the logic board is also compatible with 7410s (like the G4 processor the 500mhz cube has), but will my cube work with a 1ghz 7450/7455 (from a Quiksilver) or with a 1.42ghz 7455 (from a MDD)? I mean, do I need to install something like drivers or enablers or so, like in Action Retros Cube CPU Upgrade? (Physical fit is not the problem: these CPUs physically fit if you bend the ferrite coils over or solder them flat because they would interfere with the large heatsink) So everymac.com says that the Cube has a 100mhz bus, the QS 133mhz and the MDD 167mhz. Is this a problem? Or can I just swap the processors and be good to go?

 

[ervus]

Hello, welcome to the forum.

In my opinion, it would be a lot easier to work a few hours at minimum wage and buy a CPU upgrade for a Cube than to do what you suggest.

There is a lot of good information on this forum and the search function works well. Let us know how your project goes.

 

[weckart]

I want to upgrade the stock 450mhz processor on my Cube, but I do not want to spend 200 bucks on a single 1Ghz Sonnet upgrade on eBay. So my cube has a 7400 G4 and the logic board is also compatible with 7410s (like the G4 processor the 500mhz cube has), but will my cube work with a 1ghz 7450/7455 (from a Quiksilver) or with a 1.42ghz 7455 (from a MDD)? I mean, do I need to install something like drivers or enablers or so, like in Action Retros Cube CPU Upgrade? (Physical fit is not the problem: these CPUs physically fit if you bend the ferrite coils over or solder them flat because they would interfere with the large heatsink) So everymac.com says that the Cube has a 100mhz bus, the QS 133mhz and the MDD 167mhz. Is this a problem? Or can I just swap the processors and be good to go?

Depending upon your upgrade, you might also need a beefier VRM to handle the increased power requirements plus a fan. I think those were mostly for dual processor upgrades, though. I have a single processor Gigabyte upgrade specifically for the Cube and that came with a fan.

 

[EmilioCube]

Hello, welcome to the forum.

In my opinion, it would be a lot easier to work a few hours at minimum wage and buy a CPU upgrade for a Cube than to do what you suggest.

There is a lot of good information on this forum and the search function works well. Let us know how your project goes.

Well, as a 15 year old student, I can't have a job like you oldies
These CPU upgrades aren't even for Cubes and in both offers there is no installation cd included, so there is a risk that even these will not work.

 

[EmilioCube]

Depending upon your upgrade, you might also need a beefier VRM to handle the increased power requirements plus a fan. I think those were mostly for dual processor upgrades, though. I have a single processor Gigabyte upgrade specifically for the Cube and that came with a fan.

Which bus speed does your upgrade have? 100mhz, 133 or 167?
Do you need a beefier VRM for your upgrade and how fast is it (Dual or Single, which 74xx type)?
If you do have a better VRM, I'll try and get one as well, but I again don't want to spend so much money on an aftermarket VRM (I think that's the one Action Retro used in his Cube lol).
Every Upgrade I made to my Cube (9 already, only 8x SuperDrive and CPU aren't done yet) hadn't cost me more than 40 Euro, so spending 200 for the VRM and another 200 for the CPU is not an option for me.

I have a Noctua NF-A8 FLX (the four metal fan holders bent up to make the 25mm tall fan fit) and I think this thing has like 2000 rpm without the LNA and the ULNA (low/ultra low noise adapter) attached, so that won't be the problem.
I spotted a 10 Euro dual 7455 1.25ghz on kleinanzeigen.de (german version of ebay), does that need so much more power? That would be sad.

 

[weckart]

Which bus speed does your upgrade have? 100mhz, 133 or 167?
Do you need a beefier VRM for your upgrade and how fast is it (Dual or Single, which 74xx type)?
If you do have a better VRM, I'll try and get one as well, but I again don't want to spend so much money on an aftermarket VRM (I think that's the one Action Retro used in his Cube lol).
Every Upgrade I made to my Cube (9 already, only 8x SuperDrive and CPU aren't done yet) hadn't cost me more than 40 Euro, so spending 200 for the VRM and another 200 for the CPU is not an option for me.

I have a Noctua NF-A8 FLX (the four metal fan holders bent up to make the 25mm tall fan fit) and I think this thing has like 2000 rpm without the LNA and the ULNA (low/ultra low noise adapter) attached, so that won't be the problem.
I spotted a 10 Euro dual 7455 1.25ghz on kleinanzeigen.de (german version of ebay), does that need so much more power? That would be sad.

jumpered from 1.4 to 1.6GHz and stable at all of these I have it running at 1.6GHz. Single processor. No idea what the actual processor is. It came with its own heatsink and was basically a slot in replacement. Works with the stock VRM although the accompanying propoganda mentions a custom VRM bundled with the dual processor cards. I would be cautious about putting in a desktop processor without reading up further on it. Apart from potential firmware issues you need to make sure there is enough clearance for the processor heads and capacitors on the CPU card as space is tight in the Cube.

 

[EmilioCube]

Yeah, space is really tight
The only thing apart from firmware issues is that I have to get a new aluminium plate that fits between the CPU and the heatsink beacuse Dual CPUs won't contact with the stock one when unmodified. They will only contact if the plate ist turned by 90 degrees, but then the CPU screws won't fit anymore.

 

[ervus]

I updated this thread to collect some information for you:

https://forums.macrumors.com/threads/g4-cube-processor-comptibility.1881803/

You can also look on 68kmla.org or archives of cubeowner.com to get some good info.

 

[EmilioCube]

Thanks, I'll look the infos up there!

 

[EmilioCube]

Oh Jesus, that's all Information I could ever want! Thank you so much! (Well, somehow i can't handle the search function, because i didn't find this thread before lol)

 

[EmilioCube]

Let us know how your project goes.

So I just thought I give you a detailled overview of what I have done to my Cube so far.
First the story how I got it. It has been given to me free by a person I haven't seen before that just put it in a shop window, price based on negotiaton. After having a quick look at it (the shop is on my school way and I didnt knew such a thing like the Cube existed to that point) I found that the Cube looked so awesome that I made her an offer. At the meeting, the seller wanted to try the Cube out if it still worked. But it didn't. So she said that I should take it home and try to make it work again. After that, we could talk about the price. After I mailed her that I got the PSU working with the oven/hairdryer method, she was so amazed by my "creativity" that she gave it to me for free.
So I first got a new third party PSU that fits into the plastic case of the original PSU and while assembling (back then, I was a rookie, now, I'm not anymore, I hope), I got a 230V electric shock (Yikes!) and learned my lesson to be a lot more careful in what I am doing.
I got 1.5 Gigs of RAM, the CD/DVD eject mechanism repaired, new rubbers for the speakers as the old ones were trash, a 128 Gigabyte SSD with 3D-printed housing so it doesn't wobble around, new thermal paste, two USB splitter cables for more USB sticks (USB 1.1 is still a pain, I can't access my iPod shuffle "G4" because it requires USB 2.0 (why?)), a GeForce 6200 laying around still not being flashed yet, an AirPort card that I can't use beacuse my stupid Telekom router doesn't support the old WEP, so I have to use the LAN port as before, and a FireWire enclosure for the old HDD to boot up the Cube from it to see what's wrong with the SSD beacuse it didn't boot up properly after I tried to boot a damaged native OS 9 and wasn't even able to boot with pressed alt button to change the startup volume.
Last week I got a 4-pin Noctua but haven't used it as the cheap China fan controller hasn't arrived yet. And

I have a Noctua NF-A8 FLX

was false, I actually have a NF-A8 PWM that supports PWM as the name says so the controller will adapt the fan speed to the temperature.
Still missing is a CD/DVD burner (maybe the SuperDrive from the MDD I will get soon, does that one fit and work in Cubes?), flashing the GeForce, a Bluetooth antenna, and a 23" ADC display with ADC to DVI adapter that I could use instead of the trashy LG screen I'm using right now. Also I will get a set of small heatsinks that I could attach to some components of the VRM. So that's all for now and I will update you as soon as I make any changes to my Cube.
(Written and edited from my Cube)

 

[EmilioCube]

So I have a Question to the VRM.
It has 8 places for MOSFETs but only six are actually soldered onto it. Could I make the VRM (a bit) stronger with getting two fitting MOSFETs and attaching some small heatsinks to them? I think these should be pretty cheap if one finds the right ones.

 

[EmilioCube]

Could this one work? Link

 

[EmilioCube]

So I got the MDD yesterday and it is a 1.25Ghz Dual that would only work in my Cube at a clock speed of 750mhz, but I finally found the data sheet of the 74xx from Motorola so that I would be able to overclock it to something like 1.4Ghz with resoldering some resistors but I will try it out first w/o overclocking. Next step would be to resolder the three coils to make them sit flat. I also found 10 pieces of the newer MOSFET version that I could attach to the VRM (not 10 but 8 of course). I also ordered a copper plate to fit between the CPU and the heatsink. I placed the new CPU (for testing if it works) in my open Cube and it bongs! (Shutted it down after the Bong)

 

[EmilioCube]

And the cheap fan controller that just arrived an hour ago works great with the noctua in my cube!

 

[EmilioCube]

So finally there again is going something in this thread, I managed to get some stuff to complete the upgrade and will be able to actually use it in my Cube. So I got new ferrit cores, some isolated copper wire, a copper plate and some thermal tape. (btw haven’t soldered the isolated wire to the CPU board but I will
After destroying my Cubes VRM, CubeUs worked hard on his own custom one and I ordered it already.
Big shoutout to him, great work!
This is how it looks:

In the field of coils etc. I totally am a noob. So if that what I made is trash just say it 🤣
I also drilled up the two big holes for the screws that fix the logic board and the CPU to the heatsink so that the screws fit. And because the CPU is very wobbly without the third screw attached I just took the spring of it and placed it between logic board and the MDD CPU. It now is pressed to the copper plate on the heatsink just perfectly.
I don’t think it will blow up the stock VRM as the resistors haven’t been modified yet so it will only run at 750mhz instead of the 1,25ghz. If it works and CubeUs’ VRM arrives I think I will try 1,3ghz and then 1,4 but not more.

 

[cuebus]

Did you measure the inductance of the coils before you replaced them? Inductor cores are a material science in and of themselves and there are many parameters that go into their construction. Though you have perhaps matched the wire size and turns count, you should make an effort to determine the inductance and core saturation characteristics of the original. If you are lucky, it is already well matched and you should have no issues. If you are unlucky, you will have voltage that is not well stabilized and experience kernel panics and/or overheating of the cpu.

Otherwise, exciting to see this pan out if it does as I might be interested in something similar too.

 

[indibil]

Great!

 

[bkmoore773]

In the field of coils etc. I totally am a noob. So if that what I made is trash just say it...

Ham radio nerd here. The two things that matter are core material and number of turns. Each pass through the middle of the core counts as one turn. If you put multiple windings around a single core, then they all need to be in the same sense (direction), i.e. going into the core, or coming out of the core. If you reverse direction, you just canceled out the winding, i.e. 4 LT + 2RT = 2 LT.

The diameter or gauge of the wire isn't important, only that it is a suitable gauge for the electrical current. More current means thicker wire gauge. Having long leads connected to your core will increase inductance, since wire by itself has induction, so your coils will have more inductance than the OEM ones if all else is equal. Tolerances on inductance are very large, so it's not too important to match the inductance exactly, and probably won't make much of a difference.

Another thing to consider, and what pops out at me looking at the pictures are that long leads can cause problems at high AC frequencies. If the lead length is 1/10 of a wavelength or more, it can start acting as an RF antenna and a half-wave length wire would be an optimal dipole. So for example, if you have a 1GHz signal going down a wire, its wavelength is close to 12 inches. Any wire length of 1.2 inches or more would start acting as an antenna, and a 6 inch wire would be a perfect dipole and you'd have a nice transmitter on your hands. There are ways to mitigate this, such as having parallel feed lines, where you have the opposite signal going down each side and they cancel each other out.

Generally the purpose of inductors is to filter AC voltages or signals. DC can pass through an inductor unimpeded. But certain AC frequencies will be attenuated, others can pass freely. In radio we could use a series of inductors to filter out a single signal from a combined signal for example. Lastly, electrons don't have eyes and don't care about beauty. A messy looking coil is electically identical to a nice, beautifully wound one. I once had to cram over 80 turns onto a tiny coil, it looked like a mess, but it worked beautifully.

 

[Wouter3]

So finally there again is going something in this thread, I managed to get some stuff to complete the upgrade and will be able to actually use it in my Cube. So I got new ferrit cores, some isolated copper wire, a copper plate and some thermal tape. (btw haven’t soldered the isolated wire to the CPU board but I will
After destroying my Cubes VRM, CubeUs worked hard on his own custom one and I ordered it already.
Big shoutout to him, great work!
This is how it looks:
View attachment 2325776
In the field of coils etc. I totally am a noob. So if that what I made is trash just say it 🤣
I also drilled up the two big holes for the screws that fix the logic board and the CPU to the heatsink so that the screws fit. And because the CPU is very wobbly without the third screw attached I just took the spring of it and placed it between logic board and the MDD CPU. It now is pressed to the copper plate on the heatsink just perfectly.
I don’t think it will blow up the stock VRM as the resistors haven’t been modified yet so it will only run at 750mhz instead of the 1,25ghz. If it works and CubeUs’ VRM arrives I think I will try 1,3ghz and then 1,4 but not more.

I am impressed how far you have come and wonder how the processor board fits in the Cube.
On the subject of the VRM, I blew up my stock VRM and motherboard by installing a 1 GHz Sonnet board. I later bought a new MB and the Japanese VRM which at the time costed $150. Also the 1 GHz board failed on me due to failing capacitors, which I tried to replace to no avail. (I still have the board for anyone who can make it work again). In the end I bought a 1.2 GHz Sonnet processor board, that works great. I also tried to repair my stock VRM by replacing the blown up Mosfets, and two capacitors but that did not work. The lesson for you: do not try a fast processor with the stock VRM as it can also blow up your MB.
I am interested to see how the CubeUs custom VRM works and what is costs.
Have you also managed to flash your 6200 graphics card? I bought one on eBay, but the DVI port does not work, only the VGA port.

 

[EmilioCube]

The MDD processor barely fits in the

and the Ethernet board has to go out of its way for the CPU. When it works I’ll order a AirPort Base Station and hopefully will be able to connect my Cube to the internet wirelessly. Another problem were the coils as the positioning of them was pretty tricky and I had to resolver them a few times before they were in the right position. This is how it looks now:




I placed the original CPU board besides it so you can see that the third screw hole that holds the board in place between the MB and the main HS is on the MDD board not where it should be like on the stock one. So, the board gets very wobbly, therefore the two cores are not touching the HS properly. The little spring from the third screw, now unused, comes in handy here. Fixing and isolating it from the MB with Tesa was easy and it has just the right length to push the CPU to the main HS properly. Every Tesa layer is double so I can be 100% sure the spring does not cause any problems.






The fan is driven by a temperature sensitive controller as seen here, the sensor is placed between where the two cores will touch the heatsink:


I haven’t even tried using the old Motherboard again, neither the old Rage 128 Pro.
And does anyone know if in the case that the ATI Rage is dead it could damage the other components in the Cube?

Now to the GPU:
I bought a non-flashed one on eBay (Kleinanzeigen) for 20 Bucks and it just took 30 minutes to flash it successfully, the only thing that worked first try for all upgrades for my Cube I made so far 😂. Desoldering the BIOS chip, flashing it and soldering it on to the 6200 again. Both the DVI and the VGA port work just as they should.

I tried powering the cube on with a working stock CPU board but all that happened was the black box appearing after the chime and the Apple logo appearing on the screen. I will start a new topic on this problem.

 

[EmilioCube]

The story hasn't even started and it's already over.
His famous last words (quoted by Wouter3):

I was actually just about ready to install the processor in my Cube with the custom VRM from Cuebus but wanted to try it out in my MDD first. I booted up the tower and the chime came up, but suddenly I heard a soft poof and shut down the MDD. After removing the heatsink, I saw that one CPU was burnt. I guess this the reason for this is the modding I did to the ferrit coils and after doing so, they couldn’t stabilize the CPUs enough and then one burnt out.

This is a lesson for me not to start again with something crazy like this and should also be a lesson to everyone else who is not a total electronics nerd who can BGA solder CPUs on while sleeping.

I think I'll use the money I make modding and selling GeForce 6200s to buy a Sonnet/NewerTech/PowerLogix/… CPU made for the Cube and stop experimenting with CPUs. I just have to wait for one to pop up on eBay.

 

[EmilioCube]

Anyone interested in the CPU board for the price of shipping? I have no use for it anymore, and the one core that didn't blow up probably still works for BGA soldering.
Specs are: 1.25Ghz 7455A