24" Mid 2007 iMac (imac7,1) MXM graphics replacement?

ezylstra

macrumors member
Original poster
Oct 7, 2017
34
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The 24" iMac7,1 has an MDM graphics slot. I've upgraded the CPU (Intel Core 2 Duo T9500) so that using DosDude1's tool, I've gotten Mojave installed on it. If I throw in a more modern card that uses the same slot and has support in Mojave (say an AMD R9 280X MDM) think it might work? I know it wouldn't be Mac flashed. Maybe a need to manually change a kext entry to link the card to the driver? Aside from losing the splash screen (and option key function to select boot drive), could this be successful?
 

mr.steevo

macrumors 65816
Jul 21, 2004
1,293
732
The 24" iMac7,1 has an MDM graphics slot. I've upgraded the CPU (Intel Core 2 Duo T9500) so that using DosDude1's tool, I've gotten Mojave installed on it. If I throw in a more modern card that uses the same slot and has support in Mojave (say an AMD R9 280X MDM) think it might work? I know it wouldn't be Mac flashed. Maybe a need to manually change a kext entry to link the card to the driver? Aside from losing the splash screen (and option key function to select boot drive), could this be successful?
I can’t offer anything to this thread other than to ask questions of your experience with this project.
How well is Mojave running on this system?

I’d love to try the processor swap but had been under the impression it was a mammoth task. Is there a step by step guide you referred to?
 

ezylstra

macrumors member
Original poster
Oct 7, 2017
34
16
I can’t offer anything to this thread other than to ask questions of your experience with this project.
How well is Mojave running on this system?

I’d love to try the processor swap but had been under the impression it was a mammoth task. Is there a step by step guide you referred to?
Mojave works great, short of lacking WiFi support for the stock card. I'm waiting on my replacement.

I do a lot of work taking computers apart, so this was right in my ballpark.

You have to:
1. use suction cups to remove the glass
2. undo all the screws for the bezel
3. remove the RAM slot cover
4. remove the bezel carefully because you have to disconnect the camera cable
5. unscrew the display
6. carefully lift the display and disconnect the graphics cables (there are 3 cables)
7. remove a bunch of screws securing the motherboard (I did a bunch extra at first)
8. disconnect almost all the cables you can see
9. lift the motherboard out

At this point it is quite easy. Getting here without losing screws, forgetting where they go, or damaging cables is not easy. With an 11 year old computer, what have you got to lose?
 

zackkmac

macrumors 6502a
Jul 7, 2008
732
37
Tulsa
I have been looking into this pretty hard since I have a 2008 20" I'd like to upgrade as well. The best I think you can do is, as seen in this thread, maybe a 9800m GT if you can manage to get an early revision card and flash it with Mac 8800 GS firmware. The R9 cards use a newer type of connection (MXM-3.0B) than your 2007 iMac which uses MXM II; I believe Apple started using MXM III in the early 2009 24" and onwards.
 

ezylstra

macrumors member
Original poster
Oct 7, 2017
34
16
I'd come up with some of this information. I'd seen the information about the 9800GT but none of the posts fully explained why. Your point about the MXM-II interface is the most important point, even before getting to driver support. The 9800 was apparently the highest performance MXM-II card made.

As for the firmware flashing, I know that on classic MacPros, non-flashed cards work fine except you get no splash screen and in a few situations you might not get certain performance features.

One of the advantages of working with the big iMacs is the amount of space you can work with. I think bigger graphics cards aren't a problem as long as they fit the physical slot.

Thanks!

EZ