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BGA chip swaps on G3/G4 cards, motherboards, and more

k24a1

Well-known member
So this is a project I've been THINKING of taking on. I've received my 2 PowerPC 7455A chips, each rated at 1GHz, probably able to get to 1.33GHz at the most. My plan was to swap 7455A/B chips onto these computer parts:
-Dual 1GHz G4 card, early - I'm going to have to get someone to do this for me. I was thinking I could send these chips to someone I know on MR along with the card to have them swapped and to achieve at least 1.27/1.33GHz. That should be a pretty good speed boost.
-Alternatively, if I manage to get ahold of a couple of 7457s (uncertain about P/Ns!!) then I could take this card further and achieve a possible dual 1.6GHz configuration. In theory it should also perform much better than the 7455s, and run much cooler due to the smaller manufacturing node.

-Single G4 733MHz card -> 1.33GHz single, with or without L3 depending on the situation - This could be something I'd be less shy to try out. The single CPU cards are far more common and would be easier to solder on as well.

-"Tessera" iMac G4 board CPU swap+L3 - I'd like to get ahold of a 17-inch Mid-02 iMac G4 motherboard for this project solely because of the Geforce4 MX card. From what I can tell these can be swapped into the 15-inch chassis no problem. On these earlier iMac G4 boards (and even the first revision eMacs!) there are provisions for L3 cache and a PowerPC 7451 is in place, which uses the same 483-pin layout. It would be somewhat impractical (as eMacs... exist) but it would be interesting to see one of these earlier G4 iMacs with L3 cache populated AND operational.

-Sonnet Crescendo L2 300/512K -> 600MHz G4 7410, 1MB L2 - This would be an interesting one. There is not much documentation on these cards being overclocked, let alone modified. I do have one, and this one I might want to have someone work on too. I've heard certain things about 7400s and 7410s with differences in how they handle L2 cache, but I'm not sure. I do have a 7400 pulled from a 400MHz G4 card on hand, but I could probably buy a 7410 off of eBay depending on which chip would work better.

-2005 eMac with a 7448 - This should be doable as the firmware is of a later revision, but I'm not too sure. Would be cool to see a 7448 eMac running at 2.08 or even up to 2.4GHz given how high the FSB wants to go. Also considering a video chip mod if doable, would love to see a 9600 XT in the eMac running with 128MB of VRAM.

-iBook G4 12" Early04 with 1GB of internal RAM and a 7447B/7448 - This might be too much to think of, but it would be really cool to see this. I'm also thinking of finding a way to overclock the front side bus to 167MHz if possible, which could hopefully bring more throughput to this little iBook.

These are all merely my ideas, and I don't think all of this is even possible. Just something I've thought of and I thought i'd spew it out somewhere. :/
 

CC_333

Well-known member
-"Tessera" iMac G4 board CPU swap+L3 - I'd like to get ahold of a 17-inch Mid-02 iMac G4 motherboard for this project solely because of the Geforce4 MX card. From what I can tell these can be swapped into the 15-inch chassis no problem. On these earlier iMac G4 boards (and even the first revision eMacs!) there are provisions for L3 cache and a PowerPC 7451 is in place, which uses the same 483-pin layout. It would be somewhat impractical (as eMacs... exist) but it would be interesting to see one of these earlier G4 iMacs with L3 cache populated AND operational.
I have a couple of first generation eMacs! One is 700 MHz, and the other is 800 MHz. Though I loathe to open one up (they're not an easy machine to work on!) I'd happily volunteer one of their logic boards to your project, as I have one which became damaged and has a dead IDE port.

Actually, not that I think of it, the other eMac (the 800 MHz one) is actually disassembled, and the logic board is free. I can't remember if it's the one with the dead IDE port or not, but I guess for your purposes, that doesn't matter, as I tested it and it works fully otherwise (both the optical and hard drives seem to be workable off the single working port). Hmm!

If I can dig it out of storage (just made a big move, so everything's buried), would you be interested in experimenting with it?

I wouldn't mind getting it back eventually (hopefully upgraded!), but it's OK if I don't, as I have another.

c
 

k24a1

Well-known member
Not sure. I'll need a good amount of practice for working on BGA chip swaps, and maybe even some new equipment. Also, I don't have a 2002 eMac unit to test it with. Only got 2003-05 models.
 
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