replacing the pearl in the clamshell. DIY iBook G3 Clamshell G4 CPU upgrade

[dosdude1]

I'm in the Seattle area with a PDQ that could use a good G4. Maybe one that can undervolt to run cooler? 🤷‍♂️

I also have the clamshell and a few others if you're swimming in G4 chips and free time, though I would say let others come first as these are all low priority.

I've had issues with G4 upgrades on the PDQ, specifically with the 300 MHz card... So, I can certainly attempt the upgrade, but I'm not 100% certain it will work. I had it work once before on what was originally a 266 MHz card. But worst case, I can swap it out to a 400 or 500 MHz G3 CPU.

 

[reukiodo]

Oh, it already has a 466MHz G3 in it, so maybe not much of an upgrade? Aside from disassembly, how can I tell which CPU this really is? Is there anything like cpuid for ppcs ?

If I can find my 366MHz blue clamshell, maybe it would have more success for a G4 upgrade?

Not sure if you do 68k, but I'd love to get a full 68040 and max ram in my 520c, though it seems rather difficult for me to find these parts.

 

[digdugpacman]

@andloph im guessing by SE models you are referring to the FireWire Clamshell (PowerBook2,2)? (The 366Mhz Non FW SE model uses a PPC750L so is fully compatible with 7400/7410s)

as @dosdude1 says the FW clamshells use the 750CXe which sadly are not pin compatible with any G4 or any other CPU apart from the 750CX and the PowerPC Gekko (we think) but the Bus speed mods are the same for both the First Gen clamshell PowerBook2,1 and FireWire Clamshell PowerBook2,2

but in theory at least, you could take a faster (say 600-700Mhz) 750CXe from a dead iMac Logicboard and transplant it onto the iBook Logicboard and make a 700Mhz G3 iBook clamshell

im guessing at 700Mhz its prolly going to want some beefed up cooling (granted the 700Mhz iMac G3 was a passive machine, but its "heatsink" was much bigger) but if your G4 Swapping a first Gen Clamshell the limit for stock cooling seems to be 450Mhz. (thats what mines at currently and it seems Ok...) but I know people who have tried 500+ have had over heating issues...

(you mention doing some work with a MBP3,1 are you trying to swap the Merom CPU for a Penryn one?)

sorry to unearth this thread but I recently bought an original clamshell and have been looking online for information about them. Was originally a bit disappointed that I got the 300mhz original but the price was right and the prospect of a g4 upgrade is pretty awesome. To go a bit off topic, when you say Gekko I'm assuming thats the same one from the gamecube, does that mean that in theory someone could hack in one of those to a later clamshell. I don't know much about how processors work but I'd imagine maybe there were some custom functions or calls or whatever, (I'm grasping at straws) built into the chip for the gamecube, would that cause it to not function correctly in a mac theoretically?

Not something I intend on doing lol, but just from an theoretical standpoint I find it extremely interesting to be able to take a chip from a game console and hack it into a computer.


Thanks so much for any insight!

 

[LightBulbFun]

yes the Gekko CPU in the game cube is heavily based on the 750CX/750Cxe down to even use the same "socket" i have been wanting to see someone try and slap one in a Mac just to see what would happen, but no ones done that yet sadly

and my soldering station is still packed away, although I have made good progress in clearing up my space to hopefully getting it setup and then I am hoping I can get the hang of plastic package BGA soldering

I already have a MBP4,1 with a dead GPU that I plan to practice on (well technically 2 but one still works for now, give or take some PCIe lanes LOL)

 

[digdugpacman]

yes the Gekko CPU in the game cube is heavily based on the 750CX/750Cxe down to even use the same "socket" i have been wanting to see someone try and slap one in a Mac just to see what would happen, but no ones done that yet sadly

and my soldering station is still packed away, although I have made good progress in clearing up my space to hopefully getting it setup and then I am hoping I can get the hang of plastic package BGA soldering

I already have a MBP4,1 with a dead GPU that I plan to practice on (well technically 2 but one still works for now, give or take some PCIe lanes LOL)

Sweet! Would be super fascinating to see if you ever perform the swap. Reading about the Wii's broadway and the Wii U's Expresso. Looks like wikipedia says that the broadway is almost identical to the 750CL but runs at 729 MHz. I wonder if there's any potential for it to be able to be swapped. Although it looks like the 740 CL is 90nm and the Broadway they got down to 63nm, but the earlier ones are 90nm. I wonder if somehow the later broadways could be put in some mac for better thermals. But I have no idea how much of a difference it'd make. If you have any interest in game consoles, the info out there on the FrankenPS3 is fascinating and they made a ton of progress with it. It involves the older ps3s 90nm RSX? chip being replaced with a later 65nm or 45nm after people realized that sony had been doing this on refurbs after the 90nm process was discontinued. The was someone who was actually doing the swaps for a while before anyone else knew. Its something I'd love to do someday although I'm not sure exactly why considering how much I use my original ps3. So the chances of me actually doing it are slim unless my 90nm gives up the ghost. But there is something so interesting about them.

While I've got you here and if you'd be so kind to let an idiot babble for a short while longer. Some people here and on youtube have asked about a GPU swap for these clamshells but to my understanding based on the response it seems the boards were constructed with a specific GPU in mind and im guessing because of that and the fact that this swap can't be done on later Ibooks there's a large or large enough difference in the motherboards. I'm seeing some mention of AGP. I'm assuming its some sort of internal connection rather than the connector I'm familiar with, but do you think it'd be possible to reconstruct a AGP connector on the ibook board and run an external GPU?

One last thing sorry! I see the earlier clams (according to wikipedia at least) had 512kb L2 backside cache 1:2 vs the newer ones 256 KB L2 Cache 1:1. Do you happen to know what the ratios mean, what the difference between backside and non backside? L2 cache is. And why it was seemingly lowered? Was it a budgeting move to put some money else where in the computer and any detriment would be offset by the increase in clock speed?

Thanks so much!

 

[LightBulbFun]

I'm seeing some mention of AGP. I'm assuming its some sort of internal connection rather than the connector I'm familiar with, but do you think it'd be possible to reconstruct a AGP connector on the ibook board and run an external GPU?

in theory you could de-solder the GPU from the board and break out the AGP signals with a custom interposer, into an actual AGP socket, its been done in PCIe from with the 2011 MBPs

but no ones actually done with an AGP Mac, it might be a bit impracticable on a portable since theres no iGPU to fall back to for internal display running

but on something like a Mac Mini G4 it could be quite fun, especially if you solder a 7448 to the Mac Mini, fit a nice powerful GPU say a Radeon X850 XT flashed FireGL X3, then stuff the guts into a G4 cube

you would basically be making a G4 cube based on an MDD type platform

One last thing sorry! I see the earlier clams (according to wikipedia at least) had 512kb L2 backside cache 1:2 vs the newer ones 256 KB L2 Cache 1:1. Do you happen to know what the ratios mean, what the difference between backside and non backside? L2 cache is. And why it was seemingly lowered? Was it a budgeting move to put some money else where in the computer and any detriment would be offset by the increase in clock speed?

backside L2 cache means the chip has external L2 cache chips connected directly to the CPU on their dedicated own bus, but they dont usually run at the same clock speed of the CPU, for example in a 500Mhz G4 Sawtooth, the L2 cache runs at 250Mhz that is a ratio of 1:2, and a lot of apple consumer macs/portables ran the L2 cache at 5:2 for example a 500Mhz Pismo runs its L2 cache at 5:2

newer CPU's have the L2 cache built into the CPU die itself and more often run at the same clock speed as the CPU itself aka 1:1, for example a 750CXe has 256KB of on die L2 cache, and this runs at the same speed as the CPU so 500Mhz CPU=500Mhz L2 cache hence 1:1

hopefully this makes sense (PS: I like the Volvo 263 GL you have as your profile picture!)

 

[dosdude1]

yes the Gekko CPU in the game cube is heavily based on the 750CX/750Cxe down to even use the same "socket" i have been wanting to see someone try and slap one in a Mac just to see what would happen, but no ones done that yet sadly

and my soldering station is still packed away, although I have made good progress in clearing up my space to hopefully getting it setup and then I am hoping I can get the hang of plastic package BGA soldering

I already have a MBP4,1 with a dead GPU that I plan to practice on (well technically 2 but one still works for now, give or take some PCIe lanes LOL)

I have a dead GameCube, so I will likely attempt this somewhat soon.

 

[digdugpacman]

in theory you could de-solder the GPU from the board and break out the AGP signals with a custom interposer, into an actual AGP socket, its been done in PCIe from with the 2011 MBPs

but no ones actually done with an AGP Mac, it might be a bit impracticable on a portable since theres no iGPU to fall back to for internal display running

but on something like a Mac Mini G4 it could be quite fun, especially if you solder a 7448 to the Mac Mini, fit a nice powerful GPU say a Radeon X850 XT flashed FireGL X3, then stuff the guts into a G4 cube

you would basically be making a G4 cube based on an MDD type platform



backside L2 cache means the chip has external L2 cache chips connected directly to the CPU on their dedicated own bus, but they dont usually run at the same clock speed of the CPU, for example in a 500Mhz G4 Sawtooth, the L2 cache runs at 250Mhz that is a ratio of 1:2, and a lot of apple consumer macs/portables ran the L2 cache at 5:2 for example a 500Mhz Pismo runs its L2 cache at 5:2

newer CPU's have the L2 cache built into the CPU die itself and more often run at the same clock speed as the CPU itself aka 1:1, for example a 750CXe has 256KB of on die L2 cache, and this runs at the same speed as the CPU so 500Mhz CPU=500Mhz L2 cache hence 1:1

hopefully this makes sense (PS: I like the Volvo 263 GL you have as your profile picture!)

Thanks so much for the reply and explanation! You did a great job explaining cache differences. As for the Volvo, thanks lol! I just needed a profile picture and grabbed a random file off my computer that was usable. I don't tend to keep a ton of stuff on this one. Thinkpad x230, really love it! Some people like to swap the x220 keyboard onto these as it was the last classic style keyboard. I've never tried the 220's but I really love the feel of the 230's. Run's fedora solid enough for me to be productive writing, but It won't run any "diversions" too distracting either! I really just wanted something that didn't sound like it was wheezing constantly. My old thinkpad drove me nuts in that regard, ran way too hot for my taste for how loud it was. My desktop sounds like a wind tunnel but thats because I'm too cheap to buy a fan controller but at least it's cool! I really like some macbooks though, I think I had a late 2011? Macbook pro that was far from fast but had every port you could fit on a laptop and always put in a valiant effort no matter what I asked of it. I think I have the ram I used in it in the x230 I'm typing on now. I think we hit a golden age of laptops around then, a lot of removable batteries, lots of I/O and much easier to dissassemble and upgrade. After that it seems like we got obsessed with making things thinner and thinner and gave up all our ports. Although the crummy screens and tiny trackpads of yesteryear are definitley not missed! I worry that of the last of the old gaurd of laptops will begin to fall to the ever marching required specs for internet browsing. Not to mention how difficult it can be to get a decent battery sometimes. But I dunno maybe things aren't so grim I rarely get a chance to use new laptops so I don't know if they're any good. I'm just not ready to drop a grand to find out! (apologies for my laptop tangent)

I think i stole that pic from the Wikipedia article. It's a bummer the 263 never got a window sticker per se. I'm not sure which bums me out more, that or the Saab 900 wagon . Its funny how many people that are into Volvos tend to be into old tech too! I guess they have similar draws to many old computers.

Are there any board schematics for the Ibooks anywhere? Or would this be a reverse engineering affair if I wanted to mess with the AGP connector? Sorry for the million questions I'll try to make this one my last!