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CPU upgrade possible in 27" Core Duo imac?

J

joudbren

macrumors regular
Original poster
Apr 13, 2007
244
1
Edmonton, Alberta, Canada
Just curious! I've seen Ifixit's teardown of the 27" and I know the socket is different on the Core Duo from the i5 and i7. Anyone know definitively if the 775 socket on the 27" Core Duo model would be able to accept a standard socket 775 Quad Core CPU and recognize all 4 cores? Might be a nice upgrade down the road for those of us that went dual core! Cheers!

James
 
Most probably the CPU will be soldered onto the logic board, thus not removable.
ktLKDUFPyGmyPPQJ.large


Also the i5 and i7 might need other logic boards than the Core 2 Duos.
 
I'm very curious about this also. It's been ages since I built my own computer. Comparing CPU upgrade price vs buying one off the shelf, is there a big gap in cost? Future expandability would take a big chunk of the PC desktop market. New iMac is just soo pretty. Competition can't come close and the price premium is worth every penny IMO. This extends to windows users!
 
spinnerlys said:
Most probably the CPU will be soldered onto the logic board, thus not removable.
Click to expand...

That is false. Its a known fact the CPUs are socketed.

In that picture you can even clearly see the lever that locks it into the socket!
 
300D said:
That is false. Its a known fact the CPUs are socketed.

In that picture you can even clearly see the lever that locks it into the socket!
Click to expand...

This is true, the i7 and i5 models ARE socketed and the processors is removable. That said, Apple used this processor on an obscure LGA 1156 socket, so that is the only CPU available right now and in the foreseeable future.
 
300D said:
That is false. Its a known fact the CPUs are socketed.

In that picture you can even clearly see the lever that locks it into the socket!
Click to expand...

Techhie said:
This is true, the i7 and i5 models ARE socketed and the processors is removable. That said, Apple used this processor on an obscure LGA 1156 socket, so that is the only CPU available right now and in the foreseeable future.
Click to expand...

Thanks for clarifying that.

Here is a thread about that "new" feature: https://forums.macrumors.com/threads/807088/

But nevertheless, are the i5 and i7 CPUs compatible with a logic board made for a Core2Duo, especially since the i7 is a variant of the Nehalem architecture?
 
Techhie said:
That said, Apple used this processor on an obscure LGA 1156 socket, so that is the only CPU available right now and in the foreseeable future.
Click to expand...

Dude... "obscure LGA 1156 socket"? The Lynnfields JUST came out last month. Let's give Intel an opportunity to expand the new product line a little bit. We'll probably get a good year or so of releases with the LGA 1156 before they move to another socket design.
 
RexTraverse said:
Dude... "obscure LGA 1156 socket"? The Lynnfields JUST came out last month. Let's give Intel an opportunity to expand the new product line a little bit. We'll probably get a good year or so of releases with the LGA 1156 before they move to another socket design.
Click to expand...

I'm just saying that it isn't the run of the mill LGA 1366 socket for the purposes of the kiddies here :p:cool:
 
joudbren said:
Just curious! I've seen Ifixit's teardown of the 27" and I know the socket is different on the Core Duo from the i5 and i7. Anyone know definitively if the 775 socket on the 27" Core Duo model would be able to accept a standard socket 775 Quad Core CPU and recognize all 4 cores? Might be a nice upgrade down the road for those of us that went dual core! Cheers!

James
Click to expand...

If it weren't for that pesky warranty sticker on on of the four heatsink screws, I'd have popped in my socket 755 Q9550 Quad Core CPU in my iMac and could let you know for sure. But alas, the practical side of me prevents me from doing so at the moment. :(

I have used this CPU in my hackintosh for awhile, and it ran fine in that machine. It's a 65W CPU, like the CPU that is in it already, so I think any extra heat the quad would generate would be negligible.

Maybe after the warranty expires, and I want to extend the life of the machine. But who am I kidding, I'll probably be on a new machine well before then. ;)
 
negatv1 said:
If it weren't for that pesky warranty sticker on on of the four heatsink screws, I'd have popped in my socket 755 Q9550 Quad Core CPU in my iMac and could let you know for sure. But alas, the practical side of me prevents me from doing so at the moment. :(
Click to expand...

I'm pretty sure this COULD work.
I'm sure by now at least one brave(?) soul has had to have tried it somewhere.

I'm also looking forward to the person who starts posting pictures and rants of trying 3 dozen different MXM video cards in there.
 
The Q9x00 Quad socket 755 chips (especially the 45mm parts like the Q9550S) would seem like the ideal upgrade cpu for this machine. I know, I know "If I wanted a Quad, I should have ordered a Quad", bleh.

Of course, Apple could have done something in firmware/efi to prevent the thing from working if not recognized.

But seeing that some other socketed machines that came out in the past few years (mac mini, mac pro) were successfully upgraded to CPU's that never even were shipped by Apple (in the case of the Mini, for example). And in that case the only thing I can see not working is the "About this Macintosh" possibly not having the correct text. And that is not a problem, and one simple to fix.

It would be great to see the iFixit or Hardmac sites swap out the CPU and let us know how it goes.
 
negatv1 said:
The Q9x00 Quad socket 755 chips (especially the 45mm parts like the Q9550S) would seem like the ideal upgrade cpu for this machine. I know, I know "If I wanted a Quad, I should have ordered a Quad", bleh.

Of course, Apple could have done something in firmware/efi to prevent the thing from working if not recognized.

But seeing that some other socketed machines that came out in the past few years (mac mini, mac pro) were successfully upgraded to CPU's that never even were shipped by Apple (in the case of the Mini, for example). And in that case the only thing I can see not working is the "About this Macintosh" possibly not having the correct text. And that is not a problem, and one simple to fix.

It would be great to see the iFixit or Hardmac sites swap out the CPU and let us know how it goes.
Click to expand...

I agree! I'm willing to bet that the "warranty void" sticker on the heatsink screw is there because Apple is fully aware that another 775 Socket T CPU will work and wants to discourage people taking their iMac's apart.

Guess we'll just have to wait and see if anyone tries this, at this point I'm not willing to kill my warranty on a 1 week old unit but next year..... maybe....

Cheers!

P.S. Thanks to everyone that has responded so far but just to clarify: The Core 2 models use Socket 775 and it is socketed and is removable. The i5/i7 models are also socketed with LGA 1156 socket and I'm assuming are also removable. You cannot use the i5/i7 in the socket 775 on the Core2 motherboard. My original question was strictly regarding whether or not a Socket 775 Quad Core CPU will work in place of the original dual core. Thanks again!

James
 
While it may not be cost effective to upgrade a 27" iMac to a Q9550S (Core 2 Quad, 2.83 Ghz, 12MB Cache, 65W), because it would cost more than ordering the i5, I can see a few circumstances in which it might be desirable (if you already own the Q9550S).

More notably though, if you just need processor power and not a beefy GPU, you could buy a 21.5" iMac and put a Q9550S in there for $350, bringing the total cost to $1549.

Both processors have the same TDP, but the Q9550S has 4x the Cache (12MB vs. 3MB), and 4 cores running at 2.83Ghz, vs. 2 cores running at 3.06Ghz.

Now we just need to find someone to try it! I have a feeling it would work.
 
Have the cpu, have the iMac... If it weren't for that damned little sticker.

But, I'm starting to get the urge. What the hell, you only go around once, right? ;)


And BTW, microcenter has had the Q9550's for well under $200 for a while now. I've been running it in my DorkPro for a few months, and it is a great cpu.
 
negatv1 said:
But, I'm starting to get the urge. What the hell, you only go around once, right? ;)
Click to expand...
Haha, is there any way to remove that sticker without ripping it? Perhaps apply a little steam? We need to find a stamp collector for some expert advice.

I'm really curious about this. I really think it would work.
 
sfroom said:
Haha, is there any way to remove that sticker without ripping it? Perhaps apply a little steam? We need to find a stamp collector for some expert advice.

I'm really curious about this. I really think it would work.
Click to expand...

OEMs have spent tons of money to make sure that a warranty sticker only works one time.
 
Long story short...


The Q9550 cpu doesn't work. Turns on, black screen no boot. Throw the old CPU in there and it works just fine. Have to guess that Apple locked down the firmware to a couple cpuid's or something similar.

FWIW, I now know the insides of my imac inside and out. And word to the wise, the iFixit teardown misses alot of steps/connectors, but is a good general reference.
 
Is it a Q9550 or a Q9550s? I assume a Q9550 wouldn't work. That CPU has a 95W TDP. The Q9550s is the low TDP version, and has a TDP of 65W, the same as the new iMacs CPU.

But thanks for experimenting! What a cool project.
 
sfroom said:
Is it a Q9550 or a Q9550s? I assume a Q9550 wouldn't work. That CPU has a 95W TDP. The Q9550s is the low TDP version, and has a TDP of 65W, the same as the new iMacs CPU.

But thanks for experimenting! What a cool project.
Click to expand...


Yeah, I got sick of not knowing and really. It's just a piece of hardware thats going to be replaced in a year anyways.

So, yeah I thought I had a Q9550s, as it is a 45nm part, but it looks like isn't after all. So I guess If somebody had a Q9550s, there might still be hope. Send me one, and I'll gladly try it out. Just not interested enough in buying one. :)

I did some pics that I'll probably post to my site.

BTW, my 27inch uses a 1TB Seagate 7200.12, and not a WD Caviar Black.
 
negatv1 said:
Yeah, I got sick of not knowing and really. It's just a piece of hardware thats going to be replaced in a year anyways.

So, yeah I thought I had a Q9550s, as it is a 45nm part, but it looks like isn't after all. So I guess If somebody had a Q9550s, there might still be hope. Send me one, and I'll gladly try it out. Just not interested enough in buying one. :)

I did some pics that I'll probably post to my site.

BTW, my 27inch uses a 1TB Seagate 7200.12, and not a WD Caviar Black.
Click to expand...

I'd love to see some pics posted. The iFixIt teardown leaves a lot to be desired. Kudos on your effort. If someone manages to get a 9550s working, I'd seriously consider upgrading once the price of the CPU drops a bit.
 
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