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Interest in adapting 744x to 7400?

herd

Well-known member
I was looking at the pin-out for the 7447 and I think it could be adapted to the 7400. Would people be interested in this? The main application I can see would be to install faster 7447 chips onto these boards for use in the Cube:

533cpub.jpg

These boards fit a Cube and are relatively available; the 7447 chips are also available.

The 7400 pin-out is also similar to the pin-out on a few versions of "G3" chips, so an adapter might allow 7447 chips to be installed on a few different G3 boards. The Pismo comes to mind, from this thread:


Or maybe time would be better spent on recreating that adapter between the 750 and 750FX pin-outs? Those chips are also available and go up to 1GHz or so.
 

Byrd

Well-known member
Would the interposer (I'm assuming) cause height issues needing significant mods to the G4 Cube heatsink?
 

herd

Well-known member
Yes, I'm talking about an adapter. With a new board you could do whatever you want.

In case the link goes dead, here are a couple of the pictures:

750FXa.jpg


750FXb.jpg
 

LightBulbFun

Well-known member
ooh yeah id be very interested in seeing an interposer developed!

I know there is someone on here who has made a 7450-7455 BGA483 to BGA360 interposer to retrofit 7447A's and 7448's to existing DA/QS/MDD cards

but it would be awesome to see such an interposer for all the other PPC CPU's "sockets" :) esp something like the 750CX/CXe socket

would be lots of fun to cram a 7448 into an iBook G3 clamshell or iMac G3 :) and having an interposer for the original 750/7400 socket would be good for upgrading everything from Kanga's to Pismo's :) and it would also be neat to see the Above 750GX interpose recreated :)


(as a side note id love to see one of the BGA483-BGA360 interposed slapped onto a Sonnet 7450/7455 G4 7300-9600 upgrade card and make a completely Over powered 7448 based 9600 LOL)
 

Nixontheknight

Well-known member
ooh yeah id be very interested in seeing an interposer developed!

I know there is someone on here who has made a 7450-7455 BGA483 to BGA360 interposer to retrofit 7447A's and 7448's to existing DA/QS/MDD cards

but it would be awesome to see such an interposer for all the other PPC CPU's "sockets" :) esp something like the 750CX/CXe socket

would be lots of fun to cram a 7448 into an iBook G3 clamshell or iMac G3 :) and having an interposer for the original 750/7400 socket would be good for upgrading everything from Kanga's to Pismo's :) and it would also be neat to see the Above 750GX interpose recreated :)


(as a side note id love to see one of the BGA483-BGA360 interposed slapped onto a Sonnet 7450/7455 G4 7300-9600 upgrade card and make a completely Over powered 7448 based 9600 LOL)
800MHz+ would be really nice on a 9600
 

indibil

Well-known member
ooh yeah id be very interested in seeing an interposer developed!

I know there is someone on here who has made a 7450-7455 BGA483 to BGA360 interposer to retrofit 7447A's and 7448's to existing DA/QS/MDD cards

but it would be awesome to see such an interposer for all the other PPC CPU's "sockets" :) esp something like the 750CX/CXe socket

would be lots of fun to cram a 7448 into an iBook G3 clamshell or iMac G3 :) and having an interposer for the original 750/7400 socket would be good for upgrading everything from Kanga's to Pismo's :) and it would also be neat to see the Above 750GX interpose recreated :)


(as a side note id love to see one of the BGA483-BGA360 interposed slapped onto a Sonnet 7450/7455 G4 7300-9600 upgrade card and make a completely Over powered 7448 based 9600 LOL)
Good idea! my iMac G3 500MHz with 750CX want this interposer board!!!!!!!
 

zarky

Member
Not to boost an older thread, but i would be interested to see what the most G4 you could stuff into a Pismo would be. I'm about as dumb as it comes with this stuff, but am I reading that there could be a possibility of a 7448 G4 in a pismo? Cooling issues aside, of course.
 

ried

Well-known member
I'd love to see a 7447 on a 7400 ZIF daughtercard (Sonnet, Yikes) for my G3 All-in-One. The Sonnet 1GHz G4 ZIF upgrades are unobtanium.
 

Phipli

Well-known member
I'd love to see a 7447 on a 7400 ZIF daughtercard (Sonnet, Yikes) for my G3 All-in-One. The Sonnet 1GHz G4 ZIF upgrades are unobtanium.
The Sonnet 1GHz ziff cards use external power, would it be better to go for a 750fx - you lose Altivec, but they are lower power and as fast for non-altivec stuff?

@Siliconinsider was previously working on something like the Powerlogix card, but I think he hit some issues sadly. Not sure what the current project status is :)
 

ried

Well-known member
The Sonnet 1GHz ziff cards use external power...
That's a really good point. What's the power limit of a ZIF socket without additional external power? The 7447 designs have mobile applications, so my assumption is that they're relatively power efficient - but they may still use significantly more power than the G3's ZIF socket could deliver.
 

cobalt60

Well-known member
1GHz 750GX has a typical power draw of 8.3W @ 1GHz.
1GHz 7447A has a typical power draw of 16W @ 1GHz
533MHz 7410 has a typical power draw of 5.3W @ 500MHz
I am also curious what (all the variants of) a ZIF socket will deliver. I would be worried about any G4 other than a 7410.
Not sure what the power draw of the backside cache chips are, but I think it would be relevant.
 

zarky

Member
I wonder if in a situation like a pismo, one could tap an extra 5v from the hard drive power supply or something for a 7447. I have a 7410 powered pismo and ive been brainstorming a better cooling solution that would fit into the HDD bay after I swap to a mini-SSD
 

herd

Well-known member
The main application I can see would be to install faster 7447 chips onto these boards for use in the Cube

I guess I never followed up on this thread. In case any Cube enthusiasts care, the chip swaps I mentioned work fine. A 7447 at 1.2GHz uses roughly the same peak power as the stock Cube CPU. I think 1.4GHz is still conservative enough to use the stock VRM, but fan(s) should be added. Anyway, FYI.


cube7447b.jpg
 

herd

Well-known member
The Dual CPU swaps also work. I've been running this in my Cube for a while at dual 1.2GHz.

cube7447d.jpg
 

François

Well-known member
I’m a Cube enthusiast! I’ve just discovered this thread. I’m very much interested!

So, how one does such a CPU swap? I’m guessing you need specialized soldering equipment?
 
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