iMac G5 with 4.5GB of RAM

[x_orange90_x]

I just came across this thread and I'm astounded to see it's been recently active!

I have a iMac G5 A1195 with the Core 2 Duo. It's still stock with the 512mb RAM, and I was wondering if this model can take 4gb. From the pictures in this thread I see it's desktop memory which surprises me. Does it take any speed of DDR2?

Also, has anyone tested performance with Lion after upgrading theirs to 4.5gb?

Thanks

 

[Amethyst1]

I have a iMac G5 A1195 with the Core 2 Duo.

If it's an A1195, it's not an iMac G5... and it doesn't have a Core 2 Duo either, but a Core Duo.

It's still stock with the 512mb RAM, and I was wondering if this model can take 4gb.

If it's a Core Duo, it can take 2 GB. If it's a Core 2 Duo (use About This Mac to check), you can install 4 GB but only three-point-something GB will be usable due to a chipset limitation. So there's no way to actually use 4 GB RAM.

 

[x_orange90_x]

If it's an A1195, it's not an iMac G5... and it doesn't have a Core 2 Duo either, but a Core Duo.


If it's a Core Duo, it can take 2 GB. If it's a Core 2 Duo (use About This Mac to check), you can install 4 GB but only three-point-something GB will be usable due to a chipset limitation. So there's no way to actually use 4 GB RAM.

Hi, thanks for the reply!

I'll have to double check About page. I do know it's 1.83GHz but it also has the iSight camera.

 

[Amethyst1]

I do know it's 1.83GHz but it also has the iSight camera.

If it's 1.83 GHz and has never been upgraded, it's a Core Duo (32-bit) model and can use 2 GB RAM maximum. You'd have to upgrade the CPU to a Core 2 Duo (64-bit) to be able to use more RAM.

EDIT: I was wrong. The second “educational market” 17” model with the Intel GMA 950 (iMac5,2) does have a 1.83 GHz Core 2 Duo T5600.

 

[x_orange90_x]

If it's 1.83 GHz and has never been upgraded, it's a Core Duo (32-bit) model and can use 2 GB RAM maximum. You'd have to upgrade the CPU to a Core 2 Duo (64-bit) to be able to use more RAM.

It's a Core 2 Duo. And I guess I have 1gb in it. Haven't played with it much, rather I've been going off the picture of the serial tag I took on my phone. So it *should* take ~3.5gb RAM then?

See attached pics

 

[pc297]

If it's 1.83 GHz and has never been upgraded, it's a Core Duo (32-bit) model and can use 2 GB RAM maximum. You'd have to upgrade the CPU to a Core 2 Duo (64-bit) to be able to use more RAM.

Which is indeed the case but if you think of it is kinda weird since the 32-bit Core Duo (Yonah) should be able to address 4Gb, let alone that it has PAE so in theory more ! That's Apple for you and sometimes somewhat random firmware limitations.

On the mini, I don't know if it was the 1,1->2,1 firmware update alone or in combination with the Core2 Duo CPU that allowed 4Gb, the flashing process needed to be done on a Core Duo, I somehow recall booting into SL before upgrading to the Core 2 Duo but I don't recall trying 4Gb on the Core Duo (it could be that I did try it on the Core Duo and that it didn't boot but I can't be sure), but certainly on the T7600 and successfully.

As a result that 4Gb T7600 2006 mini that I had found in a skip back then (as in 2007), having been discarded due to a broken PSU, SSD- and Blu-Ray -upgraded, lasted me until last year as a main media station until I had enough of having to juggle between SL, ML 32-bit NexPostFacto - great work @parrotgeek btw - and Yosemite depending on whether we were watching Netflix, Amazon Prime, Youtube, EyeTV or simply having it sleep which sadly isn't possible under Yosemite with the 10.6.2 64-bit beta GMA950 kext; but it's still going, my son is using it as his main machine. Rock solid machine in any case!

Btw which is why I'm wondering if there's anyway that rEFIt/rEFInd/OCLP can be used in some way to perform the hack we did in OF for the G5, but I don't know if any of those support any kind of comprehensive hardware/firmware control the likes of OF.

 

[Amethyst1]

Which is indeed the case but if you think of it is kinda weird since the 32-bit Core Duo (Yonah) should be able to address 4Gb, let alone that it has PAE so in theory more ! That's Apple for you and sometimes somewhat random firmware limitations.

IIRC all Pentium M/Core Solo/Core Duo systems are limited to 2 GB, irrespective of the manufacturer.

It's a Core 2 Duo.

Oops. You have the rare “educational market” 17” Core 2 Duo model with Intel GMA 950 graphics (iMac5,2). That’s the only iMac to have a 1.83 GHz Core 2 Duo. I didn’t think of that model when you mentioned 1.83 GHz (sorry!). And yep, around 3.3…3.5 GB should be addressable.

 

[B S Magnet]

Oops. You have the rare “educational market” 17” Core 2 Duo model with Intel GMA 950 graphics (iMac5,2). That’s the only iMac to have a 1.83 GHz Core 2 Duo. I didn’t think of that model when you mentioned 1.83 GHz (sorry!). And yep, around 3.3…3.5 GB should be addressable.

Come on, @Amethyst1 ! GET WITH THE PROGRAMME! ;D

(Just to be clear, I wouldn’t have thought about the Core 2 Duo 1.83GHz variant, either!)

 

[x_orange90_x]

IIRC all Pentium M/Core Solo/Core Duo systems are limited to 2 GB, irrespective of the manufacturer.


Oops. You have the rare “educational market” 17” Core 2 Duo model with Intel GMA 950 graphics (iMac5,2). That’s the only iMac to have a 1.83 GHz Core 2 Duo. I didn’t think of that model when you mentioned 1.83 GHz (sorry!). And yep, around 3.3…3.5 GB should be addressable.

Figures I get the educational model 😆 I have an educational eMac G3 as well. I guess it's a trade off in this case. I get a better CPU but get shafted on The GPU. I found this in the thrift shop for $35 so I had to have it.

Thanks for the help! I dug through my ram last night and found several 1gb sticks of DDR2, but no 2gb. When I figure out how to open this thing I'll pop in a couple and see what happens.

 

[Amethyst1]

Figures I get the educational model 😆 I have an educational eMac G3 as well. I guess it's a trade off in this case. I get a better CPU but get shafted on The GPU. I found this in the thrift shop for $35 so I had to have it.

Think positively: you don't have a discrete GPU so it can't fail. And I guess those edu Intel iMacs are somewhat rare.

 

[dextructor]

make sure it's all functional (e.g. make -j2 or -4, should do it on the iMac G5)

Since I've been "traumatized" trying to compile things on OSX thought MacPorts and having the sensation that it was much slower than compiling it in "Real Linux" I never touched again any compiler on OSX, but if I'm wrong I would love to know. But I tested with many VPC7 machines at the same time and didn't have out of memory in my tests.

How do you boot Void?

I use the excellent guide from MorphOS to dual boot and learned the commands to proper identify the OS method combined with the OpenFirmware Wiki description, it was just putting the pieces together. And my iMac boot automatically to Void. But since Void don't have this limitation, I would apply any patch just to OSX.

check out this very simple solution found by @sasho648 which involves creating a .ramsc file:

Thanks! I will try latter, but seems very detailed and probably will work just fine.

unless anyone has ever come across 8Gb DDR2 UDIMMs

That was my hope to find such large RAM because making a computer with just 1 slot?! Those engineers at Apple should be punished for making such a disservice coming from a easy to service computer like the first generation iMac G5 to this latest pain in the ***

Thanks for the help!

 

[x_orange90_x]

So quick update. I was able to bump up to 1.5gb last night after swapping out a 512mb stick for a 1gb one. Surprisingly though my model takes laptop memory, not desktop like I had previously thought

 

[netsrot39]

Surprisingly though my model takes laptop memory, not desktop like I had previously thought

That is not surprising at all since you have an Intel iMac. While the iMac G5 and the early white Intel iMacs looks pretty much the same from the outside, they are vastly different on the inside. I know because I have a Late 2006 iMac and a Late 2005 iMac G5. After upgrading both to an SSD, I noticed that they redesigned the Intel one quite substantially. I don't think you can even swap parts from a G5 to an Intel one (besides SATA drives and perhaps the LCD). Anyways, as far as I know all Intel iMacs use laptop memory DIMMs while all iMacs prior to them use desktop style memory (or a mix of both like in the iMac G4)

 

[Intell]

For those early generation Intell Macs, like the 2006 iMac and Mac Mini, it's the firmware update that enables the machine to boot with more than 2GB installed. Even with a CoreDuo and its 2GB limitation, it'll still boot with 4GB installed. There was only an official firmware update for the iMac, it can be used to turn the iMac4,x into an iMac5,x. A similar firmware update was created by the community to turn the MacMini1,1 into a MacMini2,1 and allow it to use 4GB. There is not a similar update for the Macbook1,1 likely because it has a soldered on CoreDuo and cannot use anything above 2GB.

 

[sailorMH]

Since the G5 architecture is obviously able to address over 2GB unlike G4s

All G4 has 36-bit physical address bus ( and 52-bit virtual ). So they are easily adressable upto 64 GB of physical RAM. Unfortunatelly this feature was not used on Powermacs. ( And I also don't know any other computer which use this feature ).

But return to iMac G5: I have 4.5 GB in mine iMac G5 iSight 20". There are photos of RAM, maybe it helps:
Memory, RAM chips.

And there is OS available memory: MacOS X, MacOS X finder, Debian

 

[B S Magnet]

All G4 has 36-bit physical address bus ( and 52-bit virtual ). So they are easily adressable upto 64 GB of physical RAM. Unfortunatelly this feature was not used on Powermacs. ( And I also don't know any other computer which use this feature ).

But return to iMac G5: I have 4.5 GB in mine iMac G5 iSight 20". There are photos of RAM, maybe it helps:
Memory, RAM chips.

And there is OS available memory: MacOS X, MacOS X finder, Debian

Based on what you know, do you think this feature would have required additional, kernel-level code for the system to be able to access, or do you think this feature was disabled deliberately at a kernel level?

 

[sailorMH]

Based on what you know, do you think this feature would have required additional, kernel-level code for the system to be able to access, or do you think this feature was disabled deliberately at a kernel level?

I think main problem is with hardware design - CPU higher address pins are not connected.

I checked only one Powerbook scheme, and Maxbus between CPU and Northbridge has only ADDR<31..0> wires.
Probably used northbridges are not generally capable more than 32 address pins.

 

[Project Alice]

All G4 has 36-bit physical address bus ( and 52-bit virtual ). So they are easily adressable upto 64 GB of physical RAM. Unfortunatelly this feature was not used on Powermacs. ( And I also don't know any other computer which use this feature ).

But return to iMac G5: I have 4.5 GB in mine iMac G5 iSight 20". There are photos of RAM, maybe it helps:
Memory, RAM chips.

And there is OS available memory: MacOS X, MacOS X finder, Debian

Right, I assume the G4 memory limit is a firmware limitation. It’s irritating. Almost any PC from that era would work up to 4GB at least.

 

[ivnj]

I have a G5 with insight too. Still in the box. Surprisingly works. Has 1GB of ram. Was added directly at Apple the day we got it. Sadly it's super outdated and does not do much. And nobody on eBay is giving much either. Plus with box it's 30 pounds. So almost 100 to ship anywhere.

 

[Project Alice]

I have a G5 with insight too. Still in the box. Surprisingly works. Has 1GB of ram. Was added directly at Apple the day we got it. Sadly it's super outdated and does not do much. And nobody on eBay is giving much either. Plus with box it's 30 pounds. So almost 100 to ship anywhere.

It’s the best iMac G5, also not surprising it works. They’re the most reliable ones as far as G5s go.

If you don’t want it, hold onto it until someone buys it. They’re definitely worth more than the other ones IMO.

 

[ivnj]

It’s the best iMac G5, also not surprising it works. They’re the most reliable ones as far as G5s go.

If you don’t want it, hold onto it until someone buys it. They’re definitely worth more than the other ones IMO.

It was the best but still does nothing useful. Unless Linux loads or something somebody on reddit suggested.

 

[sailorMH]

It was the best but still does nothing useful. Unless Linux loads or something somebody on reddit suggested.

If you have iMac G5 iSight, you can try MorphOS. Forum is here. It is fast, easy-to-use has up-to-date browser and email, but number of games and applications are limited compared to MacOS X.

 

[ivnj]

If you have iMac G5 iSight, you can try MorphOS. Forum is here. It is fast, easy-to-use has up-to-date browser and email, but number of games and applications are limited compared to MacOS X.

It sounds like it's worth a try thanks. But how do you open an .hdimg?

 

[ivnj]

OK, I figured it out. But it's not booting. No distro is. Except mint but it does not boot after install.

 

[Project Alice]

OK, I figured it out. But it's not booting. No distro is. Except mint but it does not boot after install.

Can you elaborate? Did you correctly partition the drive and install the boot loader?